Sunday, June 29, 2008

ARTICLE UPDATE - Preferences for emotional information in older and younger adults: A meta-analysis of memory and attention tasks.

Murphy NA, Isaacowitz DM.

Psychology and Aging, 23, 263-286

The authors conducted a meta-analysis to determine the magnitude of older and younger adults' preferences for emotional stimuli in studies of attention and memory. Analyses involved 1,085 older adults from 37 independent samples and 3,150 younger adults from 86 independent samples. Both age groups exhibited small to medium emotion salience effects (i.e., preference for emotionally valenced stimuli over neutral stimuli) as well as positivity preferences (i.e., preference for positively valenced stimuli over neutral stimuli) and negativity preferences (i.e., preference for negatively valenced stimuli to neutral stimuli). There were few age differences overall. Type of measurement appeared to influence the magnitude of effects; recognition studies indicated significant age effects, where older adults showed smaller effects for emotion salience and negativity preferences than younger adults.

ARTICLE UPDATE - Effects of semantic relatedness on recall of stimuli preceding emotional oddballs.

Smith RM, Beversdorf DQ.

Journal of International Neuropsychological Society, 14, 620-628.

Semantic and episodic memory networks function as highly interconnected systems, both relying on the hippocampal/medial temporal lobe complex (HC/MTL). Episodic memory encoding triggers the retrieval of semantic information, serving to incorporate contextual relationships between the newly acquired memory and existing semantic representations. While emotional material augments episodic memory encoding at the time of stimulus presentation, interactions between emotion and semantic memory that contribute to subsequent episodic recall are not well understood. Using a modified oddball task, we examined the modulatory effects of negative emotion on semantic interactions with episodic memory by measuring the free-recall of serially presented neutral or negative words varying in semantic relatedness. We found increased free-recall for words related to and preceding emotionally negative oddballs, suggesting that negative emotion can indirectly facilitate episodic free-recall by enhancing semantic contributions during encoding. Our findings demonstrate the ability of emotion and semantic memory to interact to mutually enhance free-recall.

Sunday, June 22, 2008

ARTICLE UPDATE - Mirror neuron activation is associated with facial emotion processing.

Enticott PG, Johnston PJ, Herring SE, Hoy KE, Fitzgerald PB.

Neuropsychologia, in press

Theoretical accounts suggest that mirror neurons play a crucial role in social cognition. The current study used transcranial magnetic stimulation (TMS) to investigate the association between mirror neuron activation and facial emotion processing, a fundamental aspect of social cognition, among healthy adults (n=20). Facial emotion processing of static (but not dynamic) images correlated significantly with an enhanced motor response, proposed to reflect mirror neuron activation. These correlations did not appear to reflect general facial processing or pattern recognition, and provide support to current theoretical accounts linking the mirror neuron system to aspects of social cognition. We discuss the mechanism by which mirror neurons might facilitate facial emotion recognition.

Saturday, June 14, 2008

ARTICLE UPDATE - Electrocortical and electrodermal responses covary as a function of emotional arousal: A single-trial analysis.

Keil A, Smith JC, Wangelin BC, Sabatinelli D, Bradley MM, Lang PJ.

Psychophysiology, in press

Electrophysiological studies of human visual perception typically involve averaging across trials distributed over time during an experimental session. Using an oscillatory presentation, in which affective or neutral pictures were presented for 6 s, flickering on and off at a rate of 10 Hz, the present study examined single trials of steady-state visual evoked potentials. Moving window averaging and subsequent Fourier analysis at the stimulation frequency yielded spectral amplitude measures of electrocortical activity. Cronbach's alpha reached values >.79, across electrodes. Single-trial electrocortical activation was significantly related to the size of the skin conductance response recorded during affective picture viewing. These results suggest that individual trials of steady-state potentials may yield reliable indices of electrocortical activity in visual cortex and that amplitude modulation of these indices varies with emotional engagement.

ARTICLE UPDATE - Stimulus-driven and strategic neural responses to fearful and happy facial expressions in humans.

Williams MA, McGlone F, Abbott DF, Mattingley JB.

European Journal of Neuroscience, in press

The human amygdala responds selectively to consciously and unconsciously perceived facial expressions, particularly those that convey potential threat such as fear and anger. In many social situations, multiple faces with varying expressions confront observers yet little is known about the neural mechanisms involved in encoding several faces simultaneously. Here we used event-related fMRI to measure neural activity in pre-defined regions of interest as participants searched multi-face arrays for a designated target expression (fearful or happy). We conducted separate analyses to examine activations associated with each of the four multi-face arrays independent of target expression (stimulus-driven effects), and activations arising from the search for each of the target expressions, independent of the display type (strategic effects). Comparisons across display types, reflecting stimulus-driven influences on visual search, revealed activity in the amygdala and superior temporal sulcus (STS). By contrast, strategic demands of the task did not modulate activity in either the amygdala or STS. These results imply an interactive threat-detection system involving several neural regions. Crucially, activity in the amygdala increased significantly when participants correctly detected the target expression, compared with trials in which the identical target was missed, suggesting that the amygdala has a limited capacity for extracting affective facial expressions.

ARTICLE UPDATE - Sequential modulations of valence processing in the emotional Stroop task.

Kunde W, Mauer N.

Experimental Psychology, 55, 151-156

This study investigated trial-to-trial modulations of the processing of irrelevant valence information. Participants (N = 126) responded to the frame color of pictures with positive, neutral, or negative affective content--a procedure known as an emotional Stroop task (EST). As is typically found, positive and negative pictures delayed responses as compared to neutral pictures. However, the type and extent of this valence-based interference depended on the irrelevant picture valence in the preceding trial. Whereas preceding exposure to negative valence prompted interference from positive and negative pictures, such interference was removed after neutral trials. Following positive pictures, interference from negative but not from positive pictures was observed. We suggest that these sequential modulations reflect automatic self-regulatory selection processes that help to keep the balance between attending to task-relevant information and task-irrelevant information that signals important changes in the environment.

ARTICLE UPDATE - The Montreal Affective Voices: a validated set of nonverbal affect bursts for research on auditory affective processing.

Belin P, Fillion-Bilodeau S, Gosselin F.

Behavioural Research Methods, 40, 531-539

The Montreal Affective Voices consist of 90 nonverbal affect bursts corresponding to the emotions of anger, disgust, fear, pain, sadness, surprise, happiness, and pleasure (plus a neutral expression), recorded by 10 different actors (5 of them male and 5 female). Ratings of valence, arousal, and intensity for eight emotions were collected for each vocalization from 30 participants. Analyses revealed high recognition accuracies for most of the emotional categories (mean of 68%). They also revealed significant effects of both the actors' and the participants' gender: The highest hit rates (75%) were obtained for female participants rating female vocalizations, and the lowest hit rates (60%) for male participants rating male vocalizations. Interestingly, the mixed situations--that is, male participants rating female vocalizations or female participants rating male vocalizations--yielded similar, intermediate ratings. The Montreal Affective Voices are available for download at vnl.psy.gla.ac.uk/ (Resources section).

ARTICLE UPDATE - Unpacking the cognitive architecture of emotion processes.

Grandjean D, Scherer KR.

Emotion, 8, 341-351.

The results of 2 electroencephalographic studies confirm Component Process Model (CPM) predictions that different appraisal checks have specific brain state correlates, occur rapidly in a brief time window after stimulation, and produce results that occur in sequential rather than parallel fashion. The data are compatible with the assumption that early checks (novelty and intrinsic pleasantness) occur in an automatic, unconscious mode of processing, whereas later checks, specifically goal conduciveness, require more extensive, effortful, and controlled processing. Overall, this work, combined with growing evidence for the CPM's response patterning predictions concerning autonomic physiological signatures, facial muscle movements, and vocalization changes, suggests that this model provides an appropriate basis for the unpacking of the cognitive architecture of emotion and its computational modeling.

ARTICLE UPDATE - Decoding of affective facial expressions in the context of emotional situations.

Sommer M, Döhnel K, Meinhardt J, Hajak G.

Neuropsychologia, in press

The ability to recognize other persons' affective states and to link these with aspects of the current situation arises early in development and is precursor functions of a Theory of Mind (ToM). Until now, studies investigated either the processing of affective faces or affective pictures. In the present study, we tried to realize a scenario more similar to every day situations. We employed fMRI and used a picture matching task to explore the neural correlates associated with the integration and decoding of facial affective expressions in the context of affective situations. In the emotion condition, the participants judged an emotional facial expression with respect to the content of an emotional picture. In the two other conditions, participants indicated colour matches on the background of either affective or scrambled pictures. In contrast to colour matching on scrambled pictures, colour matching on emotional pictures resulted in longer reaction times and increased activation of the bilateral fusiform and occipital gyrus. These results indicated that, although task irrelevant, participants may attend to the emotional background of the pictures. The emotion task was associated with higher reaction times and with activation of the bilateral fusiform and occipital gyrus. Additionally, emotion attribution induced left amygdala activity. Possibly, attention processes and amygdala projections modulated the activation found in the occipital and fusiform areas. Furthermore, the involvement of the amygdala in the ToM precursor ability to link facial expressions with an emotional situation may indicate that the amygdala is involved in the development of stable ToM abilities.

ARTICLE UPDATE - Emotion, decision making, and the amygdala.

Seymour B, Dolan R.

Neuron, 58, 662-671

Emotion plays a critical role in many contemporary accounts of decision making, but exactly what underlies its influence and how this is mediated in the brain remain far from clear. Here, we review behavioral studies that suggest that Pavlovian processes can exert an important influence over choice and may account for many effects that have traditionally been attributed to emotion. We illustrate how recent experiments cast light on the underlying structure of Pavlovian control and argue that generally this influence makes good computational sense. Corresponding neuroscientific data from both animals and humans implicate a central role for the amygdala through interactions with other brain areas. This yields a neurobiological account of emotion in which it may operate, often covertly, to optimize rather than corrupt economic choice.

ARTICLE UPDATE - Affective learning enhances visual detection and responses in primary visual cortex.

Padmala S, Pessoa L.

Journal of Neuroscience, 28, 6202-6210

The affective significance of a visual item is thought to lead to enhanced visual processing. However, the precise link between enhanced visual perception of emotion-laden items and increased visual responses remains poorly understood. To investigate this link, we acquired functional magnetic resonance imaging (fMRI) data while participants performed a challenging visual detection task. Grating stimuli were physically identical and differed only as a function of their previous exposure history; CS+ stimuli were initially paired with shock, whereas CS- stimuli were not. Behaviorally, subjects were both faster and more accurate during CS+ relative to CS- target detection. These behavioral results were paralleled by increases in fMRI responses across early, retinotopically organized visual cortex, which was mapped in a separate fMRI session. Logistic regression analyses revealed that trial-by-trial fluctuations in fMRI responses were closely linked to trial type, such that fMRI signal strength reliably predicted the probability of a hit trial across retinotopically organized visual cortex, including area V1. For instance, during the CS+ condition, a 0.5% signal change increased the probability of a hit from chance to 67.3-73.5% in V1-V4 (the highest increase was observed in area V1). Furthermore, across participants, differential fMRI responses to hits versus correct rejects were correlated with behavioral performance. Our findings provide a close link between increased activation in early visual cortex and improved behavioral performance as a function of the affective significance of an item.

Saturday, May 31, 2008

ARTICLE UPDATE - Affective primes suppress attention bias to threat in socially anxious individuals.

Helfinstein SM, White LK, Bar-Haim Y, Fox NA.

Behavioral Research Therapy, in press

Anxious individuals show an attention bias towards threatening information. However, under conditions of sustained environmental threat this otherwise-present attention bias disappears. It remains unclear whether this suppression of attention bias can be caused by a transient activation of the fear system. In the present experiment, high socially anxious and low socially anxious individuals (HSA group, n=12; LSA group, n=12) performed a modified dot-probe task in which they were shown either a neutral or socially threatening prime word prior to each trial. EEG was collected and ERP components to the prime and faces displays were computed. HSA individuals showed an attention bias to threat after a neutral prime, but no attention bias after a threatening prime, demonstrating that suppression of attention bias can occur after a transient activation of the fear system. LSA individuals showed an opposite pattern: no evidence of a bias to threat with neutral primes but induction of an attention bias to threat following threatening primes. ERP results suggested differential processing of the prime and faces displays by HSA and LSA individuals. However, no group by prime interaction was found for any of ERP components.

ARTICLE UPDATE - When do motor behaviors (mis)match affective stimuli? An evaluative coding view of approach and avoidance reactions.

Eder AB, Rothermund K.

Journal of Experimental Psychology: General, 2, 262-281

Affective-mapping effects between affective stimuli and lever movements are critically dependent upon the evaluative meaning of the response labels that are used in the task instructions. In Experiments 1 and 2, affective-mapping effects predicted by specific-muscle-activation and distance-regulation accounts were replicated when the standard response labels towards and away were used but were reversed when identical lever movements were labeled downwards and upwards. In Experiment 3, affective-mapping effects were produced with affectively labeled right and left lever movements that are intrinsically unrelated to approach and avoidance. Experiments 4 and 5 revealed that affective-mapping effects are not mediated by memory retrieval processes and depend on the execution of affectively coded responses. The results support the assumption that evaluative implications of action instructions assign affective codes to motor responses on a representational level that interact with stimulus evaluations on a response selection stage.

ARTICLE UPDATE - Time course of the involvement of the right anterior superior temporal gyrus and the right fronto-parietal operculum in emotional pro

Hoekert M, Bais L, Kahn RS, Aleman A.

PLoS One, 3, e2244

In verbal communication, not only the meaning of the words convey information, but also the tone of voice (prosody) conveys crucial information about the emotional state and intentions of others. In various studies right frontal and right temporal regions have been found to play a role in emotional prosody perception. Here, we used triple-pulse repetitive transcranial magnetic stimulation (rTMS) to shed light on the precise time course of involvement of the right anterior superior temporal gyrus and the right fronto-parietal operculum. We hypothesized that information would be processed in the right anterior superior temporal gyrus before being processed in the right fronto-parietal operculum. Right-handed healthy subjects performed an emotional prosody task. During listening to each sentence a triplet of TMS pulses was applied to one of the regions at one of six time points (400-1900 ms). Results showed a significant main effect of Time for right anterior superior temporal gyrus and right fronto-parietal operculum. The largest interference was observed half-way through the sentence. This effect was stronger for withdrawal emotions than for the approach emotion. A further experiment with the inclusion of an active control condition, TMS over the EEG site POz (midline parietal-occipital junction), revealed stronger effects at the fronto-parietal operculum and anterior superior temporal gyrus relative to the active control condition. No evidence was found for sequential processing of emotional prosodic information from right anterior superior temporal gyrus to the right fronto-parietal operculum, but the results revealed more parallel processing. Our results suggest that both right fronto-parietal operculum and right anterior superior temporal gyrus are critical for emotional prosody perception at a relatively late time period after sentence onset. This may reflect that emotional cues can still be ambiguous at the beginning of sentences, but become more apparent half-way through the sentence.

ARTICLE UPDATE - Audio-visual integration of emotion expression.

Collignon O, Girard S, Gosselin F, Roy S, Saint-Amour D, Lassonde M, Lepore F.

Brain Research, in press

Regardless of the fact that emotions are usually recognized by combining facial and vocal expressions, the multisensory nature of affect perception has scarcely been investigated. In the present study, we show results of three experiments on multisensory perception of emotions using newly validated sets of dynamic visual and non-linguistic vocal clips of affect expressions. In Experiment 1, participants were required to categorise fear and disgust expressions displayed auditorily, visually, or using congruent or incongruent audio-visual stimuli. Results showed faster and more accurate categorisation in the bimodal congruent situation than in the unimodal conditions. In the incongruent situation, participant preferentially categorised the affective expression based on the visual modality, demonstrating a visual dominance in emotional processing. However, when the reliability of the visual stimuli was diminished, participants categorised incongruent bimodal stimuli preferentially via the auditory modality. These results demonstrate that visual dominance in affect perception does not occur in a rigid manner, but follows flexible situation-dependent rules. In Experiment 2, we requested the participants to pay attention to only one sensory modality at a time in order to test the putative mandatory nature of multisensory affective interactions. We observed that even if they were asked to ignore concurrent sensory information, the irrelevant information significantly affected the processing of the target. This observation was especially true when the target modality was less reliable. Altogether, these findings indicate that the perception of emotion expressions is a robust multisensory situation which follows rules that have been previously observed in other perceptual domains.

Friday, May 09, 2008

ARTICLE UPDATE - Emotional words are preferentially processed during silent reading. Here, we investigate to what extent different components of the v

Mallan KM, Lipp OV, Libera M.

International Journal of Psychophysiology, in press

Affect modulates the blink startle reflex in the picture-viewing paradigm, however, the process responsible for reflex modulation during conditional stimuli (CSs) that have acquired valence through affective conditioning remains unclear. In Experiment 1, neutral shapes (CSs) and valenced or neutral pictures (USs) were paired in a forward (CS-->US) manner. Pleasantness ratings supported affective learning of positive and negative valence. Post-acquisition, blink reflexes were larger during the pleasant and unpleasant CSs than during the neutral CS. Rather than affect, attention or anticipatory arousal were suggested as sources of startle modulation. Experiment 2 confirmed that affective learning in the picture-picture paradigm was not affected by whether the CS preceded the US. Pleasantness ratings and affective priming revealed similar extents of affective learning following forward, backward or simultaneous pairings of CSs and USs. Experiment 3 utilized a backward conditioning procedure (US-->CS) to minimize effects of US anticipation. Again, blink reflexes were larger during CSs paired with valenced USs regardless of US valence implicating attention rather than anticipatory arousal or affect as the process modulating startle in this paradigm.

ARTICLE UPDATE - Emotion and attention in visual word processing-An ERP study.

Kissler J, Herbert C, Winkler I, Junghofer M.

Biological Psychology, in press

Emotional words are preferentially processed during silent reading. Here, we investigate to what extent different components of the visual evoked potential, namely the P1, N1, the early posterior negativity (EPN, around 250ms after word onset) as well as the late positive complex (LPC, around 500ms) respond differentially to emotional words and whether this response depends on the availability of attentional resources. Subjects viewed random sequences of pleasant, neutral and unpleasant adjectives and nouns. They were first instructed to simply read the words and then to count either adjectives or nouns. No consistent effects emerged for the P1 and N1. However, during both reading and counting the EPN was enhanced for emotionally arousing words (pleasant and unpleasant), regardless of whether the word belonged to a target or a non-target category. A task effect on the EPN was restricted to adjectives, but the effect did not interact with emotional content. The later centro-parietal LPC (450-650ms) showed a large enhancement for the attended word class. A small and topographically distinct emotion-LPC effect was found specifically in response to pleasant words, both during silent reading and the active task. Thus, emotional word content is processed effortlessly and automatically and is not subject to interference from a primary grammatical decision task. The results are in line with other reports of early automatic semantic processing as reflected by posterior negativities in the ERP around 250ms after word onset. Implications for models of emotion-attention interactions in the brain are discussed.

ARTICLE UPDATE - Early emotion word processing: Evidence from event-related potentials.

Scott GG, O'Donnell PJ, Leuthold H, Sereno SC.

Biological Psychology, in press

Behavioral and electrophysiological responses were monitored to 80 controlled sets of emotionally positive, negative, and neutral words presented randomly in a lexical decision paradigm. Half of the words were low frequency and half were high frequency. Behavioral results showed significant effects of frequency and emotion as well as an interaction. Prior research has demonstrated sensitivity to lexical processing in the N1 component of the event-related brain potential (ERP). In this study, the N1 (135-180ms) showed a significant emotion by frequency interaction. The P1 window (80-120ms) preceding the N1 as well as post-N1 time windows, including the Early Posterior Negativity (200-300ms) and P300 (300-450ms), were examined. The ERP data suggest an early identification of the emotional tone of words leading to differential processing. Specifically, high frequency negative words seem to attract additional cognitive resources. The overall pattern of results is consistent with a time line of word recognition in which semantic analysis, including the evaluation of emotional quality, occurs at an early, lexical stage of processing.

ARTICLE UPDATE - Not all emotions are created equal: The negativity bias in social-emotional development.

Vaish A, Grossmann T, Woodward A

Psychological Bulletin, 134, 383-403

There is ample empirical evidence for an asymmetry in the way that adults use positive versus negative information to make sense of their world; specifically, across an array of psychological situations and tasks, adults display a negativity bias, or the propensity to attend to, learn from, and use negative information far more than positive information. This bias is argued to serve critical evolutionarily adaptive functions, but its developmental presence and ontogenetic emergence have never been seriously considered. The authors argue for the existence of the negativity bias in early development and that it is evident especially in research on infant social referencing but also in other developmental domains. They discuss ontogenetic mechanisms underlying the emergence of this bias and explore not only its evolutionary but also its developmental functions and consequences. Throughout, the authors suggest ways to further examine the negativity bias in infants and older children, and they make testable predictions that would help clarify the nature of the negativity bias during early development.

ARTICLE UPDATE - In this paper we discuss the issue of the processes potentially underlying the emergence of emotional consciousness in the light of t

Kapucu A, Rotello CM, Ready RE, Seidl KN.

Journal of Experimental Psychology: Learning, Memory and Cognition, 34, 703-711

Older adults sometimes show a recall advantage for emotionally positive, rather than neutral or negative, stimuli (S. T. Charles, M. Mather, & L. L. Carstensen, 2003). In contrast, younger adults respond "old" and "remember" more often to negative materials in recognition tests. For younger adults, both effects are due to response bias changes rather than to enhanced memory accuracy (S. Dougal & C. M. Rotello, 2007). We presented older and younger adults with emotional and neutral stimuli in a remember-know paradigm. Signal-detection and model-based analyses showed that memory accuracy did not differ for the neutral, negative, and positive stimuli, and that "remember" responses did not reflect the use of recollection. However, both age groups showed large and significant response bias effects of emotion: Younger adults tended to say "old" and "remember" more often in response to negative words than to positive and neutral words, whereas older adults responded "old" and "remember" more often to both positive and negative words than to neutral stimuli.

ARTICLE UPDATE - Conscious emotional experience emerges as a function of multilevel, appraisal-driven response synchronization.

Grandjean D, Sander D, Scherer KR.

Consciousness and Cognition, in press

In this paper we discuss the issue of the processes potentially underlying the emergence of emotional consciousness in the light of theoretical considerations and empirical evidence. First, we argue that componential emotion models, and specifically the Component Process Model (CPM), may be better able to account for the emergence of feelings than basic emotion or dimensional models. Second, we advance the hypothesis that consciousness of emotional reactions emerges when lower levels of processing are not sufficient to cope with the event and regulate the emotional process, particularly when the degree of synchronization between the components reaches a critical level and duration. Third, we review recent neuroscience evidence that bolsters our claim of the central importance of the synchronization of neuronal assemblies at different levels of processing.

Monday, April 21, 2008

ARTICLE UPDATE - The affective regulation of cognitive priming.

Storbeck J, Clore GL.

Emotion, 8, 208-215

Semantic and affective priming are classic effects observed in cognitive and social psychology, respectively. The authors discovered that affect regulates such priming effects. In Experiment 1, positive and negative moods were induced before one of three priming tasks; evaluation, categorization, or lexical decision. As predicted, positive affect led to both affective priming (evaluation task) and semantic priming (category and lexical decision tasks). However, negative affect inhibited such effects. In Experiment 2, participants in their natural affective state completed the same priming tasks as in Experiment 1. As expected, affective priming (evaluation task) and category priming (categorization and lexical decision tasks) were observed in such resting affective states. Hence, the authors conclude that negative affect inhibits semantic and affective priming. These results support recent theoretical models, which suggest that positive affect promotes associations among strong and weak concepts, and that negative affect impairs such associations (Clore & Storbeck, 2006; Kuhl, 2000).

ARTICLE UPDATE - I know how you feel: task-irrelevant facial expressions are spontaneously processed at a semantic level.

Preston SD, Stansfield RB.

Cognitive, Affective and Behavioral Neuroscience, 8, 54-64.

Previous studies have demonstrated that emotions are automatically processed. Even with subliminal presentations, subjects involuntarily mimic specific facial expressions, are influenced by the valence of a preceding emotion during judgments, and exhibit slowed responses to personally meaningful emotions; these effects are due to reflexive mimicry, unconscious carryover of valence, and attentional capture, respectively. However, perception-action effects indicate that rapid processing should involve deep, semantic-level representations of emotion (e.g., "fear"), even in the absence of a clinical emotion disorder. To test this hypothesis, we developed an emotional Stroop task (Emostroop) in which subjects responded nonverbally to emotion words superimposed over task-irrelevant images of faces displaying congruent or incongruent emotional expressions. Subjects reliably responded more slowly to incongruent than to congruent stimuli, and this interference was related to trait measures of emotionality. Rapid processing of facial emotions spontaneously activates semantic, content-rich representations at the level of the specific emotion.

ARTICLE UPDATE - Emotional priming of pop-out in visual search.

Lamy D, Amunts L, Bar-Haim Y.

Emotion, 8, 151-161

When searching for a discrepant target along a simple dimension such as color or shape, repetition of the target feature substantially speeds search, an effect known as feature priming of pop-out (V. Maljkovic and K. Nakayama, 1994). The authors present the first report of emotional priming of pop-out. Participants had to detect the face displaying a discrepant expression of emotion in an array of four face photographs. On each trial, the target when present was either a neutral face among emotional faces (angry in Experiment 1 or happy in Experiment 2), or an emotional face among neutral faces. Target detection was faster when the target displayed the same emotion on successive trials. This effect occurred for angry and for happy faces, not for neutral faces. It was completely abolished when faces were inverted instead of upright, suggesting that emotional categories rather than physical feature properties drive emotional priming of pop-out. The implications of the present findings for theoretical accounts of intertrial priming and for the face-in-the-crowd phenomenon are discussed.

ARTICLE UPDATE - The persistence of attention to emotion: Brain potentials during and after picture presentation.

Hajcak G, Olvet DM.

Emotion, 8, 250-255

Emotional stimuli have been shown to elicit increased perceptual processing and attentional allocation. The late positive potential (LPP) is a sustained P300-like component of the event-related potential that is enhanced after the presentation of pleasant and unpleasant pictures as compared with neutral pictures. In this study, the LPP was measured using dense array electroencephalograph both before and after pleasant, neutral, and unpleasant images to examine the time course of attentional allocation toward emotional stimuli. Results from 17 participants confirmed that the LPP was larger after emotional than neutral images and that this effect persisted for 800 ms after pleasant picture offset and at least 1,000 ms after unpleasant picture offset. The persistence of increased attention after unpleasant compared to pleasant stimuli is consistent with the existence of a negativity bias. Overall, these results indicate that attentional capture of emotion continues well beyond picture presentation and that this can be measured with the LPP. Implications and directions for future research are discussed.

ARTICLE UPDATE - Emotion and working memory: Evidence for domain-specific processes for affective maintenance.

Mikels JA, Reuter-Lorenz PA, Beyer JA, Fredrickson BL.

Emotion, 8, 256-266

Working memory is comprised of separable subsystems for visual and verbal information, but what if the information is affective? Does the maintenance of affective information rely on the same processes that maintain nonaffective information? The authors address this question using a novel delayed-response task developed to investigate the short-term maintenance of affective memoranda. Using selective interference methods the authors find that a secondary emotion-regulation task impaired affect intensity maintenance, whereas secondary cognitive tasks disrupted brightness intensity maintenance, but facilitated affect maintenance. Additionally, performance on the affect maintenance task depends on the valence of the maintained feeling, further supporting the domain-specific nature of the task. The importance of affect maintenance per se is further supported by demonstrating that the observed valence effects depend on a memory delay and are not evident with simultaneous presentation of stimuli. These findings suggest that the working memory system may include domain-specific components that are specialized for the maintenance of affective memoranda.

ARTICLE UPDATE - Although there are many well-characterized affective visual stimuli sets available to researchers, there are few auditory sets availa

Levens SM, Phelps EA.

Emotion, 8, 267-280

The interaction between emotion and working memory maintenance, load, and performance has been investigated with mixed results. The effect of emotion on specific executive processes such as interference resolution, however, remains relatively unexplored. In this series of studies, we examine how emotion affects interference resolution processes within working memory by modifying the Recency-probes paradigm (Monsel, 1978) to include emotional and neutral stimuli. Reaction time differences were compared between interference and non-interference trials for neutral and emotional words (Studies 1 & 3) and pictures (Study 2). Our results indicate that trials using emotional stimuli show a relative decrease in interference compared with trials using neutral stimuli, suggesting facilitation of interference resolution in the former. Furthermore, both valence and arousal seem to interact to produce this facilitation effect. These findings suggest that emotion facilitates response selection amid interference in working memory.

ARTICLE UPDATE - Affective auditory stimuli: characterization of the International Affective Digitized Sounds (IADS) by discrete emotional categories.

Stevenson RA, James TW.

Behavioural Research Methods, 40, 315-320

Although there are many well-characterized affective visual stimuli sets available to researchers, there are few auditory sets available. Those auditory sets that are available have been characterized primarily according to one of two major theories of affect: dimensional or categorical. Current trends have attempted to utilize both theories to more fully understand emotional processing. As such, stimuli that have been thoroughly characterized according to both of these approaches are exceptionally useful. In an effort to provide researchers with such a stimuli set, we collected descriptive data on the International Affective Digitized Sounds (IADS), identifying which discrete categorical emotions are elicited by each sound. The IADS is a database of 111 sounds characterized along the affective dimensions of valence, arousal, and dominance. Our data complement these characterizations of the IADS, allowing researchers to control for or manipulate stimulus properties in accordance with both theories of affect, providing an avenue for further integration of these perspectives. Related materials may be downloaded from the Psychonomic Society Web archive at www.psychonomic.org/archive.

ARTICLE UPDATE - Amygdala contribution to selective dimensions of emotion.

Berntson GG, Bechara A, Damasio H, Tranel D, Cacioppo JT.

Social, Cognitive and Affective Neuroscience, 2, 123-129

The amygdala has been implicated in emotional processes, although the precise nature of the emotional deficits following amygdala lesions remains to be fully elucidated. Cognitive disturbances in the perception, recognition or memory of emotional stimuli have been suggested by some, whereas others have proposed changes in emotional arousal. To address this issue, measures of emotional arousal and valence (positivity and negativity) to a graded series of emotional pictures were obtained from patients with lesions of the amygdala and from a clinical contrast group with lesions that spared this structure. Relative to the contrast group, patients with damage to the amygdala evidenced a complete lack of an arousal gradient across negative stimuli, although they displayed a typical arousal gradient to positive stimuli. These results were not attributable to the inability of amygdala patients to process the hostile or hospitable nature of the stimuli, as the amygdala group accurately recognized and categorized both positive and negative features of the stimuli. The relative lack of emotional arousal to negative stimuli may account for many of the clinical features of amygdala lesions.

ARTICLE UPDATE - Chronometric features of processing unpleasant stimuli: a functional MRI-based transcranial magnetic stimulation study.

Kaffenberger T, Baumgartner T, Koeneke S, Jäncke L, Herwig U.

Neuroreport, 19, 777-781

The quick identification of potentially threatening events is a crucial cognitive capacity to survive in a changing environment. Previous functional MRI data revealed the right dorsolateral prefrontal cortex and the region of the left intraparietal sulcus (IPS) to be involved in the perception of emotionally negative stimuli. For assessing chronometric aspects of emotion processing, we applied transcranial magnetic stimulation above these areas at different times after negative and neutral picture presentation. An interference with emotion processing was found with transcranial magnetic stimulation above the dorsolateral prefrontal cortex 200-300 ms and above the left intraparietal sulcus 240/260 ms after negative stimuli. The data suggest a parallel and conjoint involvement of prefrontal and parietal areas for the identification of emotionally negative stimuli.

Monday, April 14, 2008

ARTICLE UPDATE - The amygdala and the experience of affect.

Barrett LF, Bliss-Moreau E, Duncan SL, Rauch SL, Wright CI.

Social Cognitive Affective Neuroscience, 2, 73-83

The current study examined the hypothesis that amygdala activation serves as a neural precondition for negative affective experience. Participants' affective experience was measured by asking them to report on their momentary experiences several times a day over the course of a month using an electronic experience-sampling procedure. One year later, participants viewed backwardly masked depictions of fear while functional magnetic resonance imaging was used to measure their amygdala and fusiform gyrus activation. Negative affect, as measured during the experience-sampling procedure 1-year prior, was positively correlated with amygdala activation in response to these brief presentations of fear depictions. Furthermore, descriptive analyses indicated that fusiform gyrus activation and negative affective experience in the scanner were associated for participants reporting increased nervousness during the imaging procedure. The results are consistent with the interpretation that the amygdala contributes to negative affective experience by increasing perceptual sensitivity for negative stimuli.

ARTICLE UPDATE - Prefrontal cortex damage abolishes brand-cued changes in cola preference.

Koenigs M, Tranel D.

Social Cognitive Affective Neuroscience, 3, 1-6

Human decision-making is remarkably susceptible to commercial advertising, yet the neurobiological basis of this phenomenon remains largely unexplored. With a series of Coke and Pepsi taste tests we show that patients with damage specifically involving ventromedial prefrontal cortex (VMPC), an area important for emotion, did not demonstrate the normal preference bias when exposed to brand information. Both comparison groups (neurologically normal adults and lesion patients with intact VMPC) preferred Pepsi in a blind taste test, but in subsequent taste tests that featured brand information ('semi-blind' taste tests), both comparison groups' preferences were skewed toward Coke, illustrating the so-called 'Pepsi paradox'. Like comparison groups, the VMPC patients preferred Pepsi in the blind taste test, but unlike comparison groups, the VMPC patients maintained their Pepsi preference in the semi-blind test. The result that VMPC damage abolishes the 'Pepsi paradox' suggests that the VMPC is an important part of the neural substrate for translating commercial images into brand preferences.

ARTICLE UDPATE - Basic tastes and basic emotions: Basic problems and perspectives for a nonbasic solution.

Sander D.

Behavioural Brain Research, 31, 88.

Contemporary behavioral and brain scientists consider the existence of so-called basic emotions in a similar way to the one described by Erickson for so-called basic tastes. Commenting on this analogy, I argue that similar basic problems are encountered in both perspectives, and I suggest a potential nonbasic solution that is tested in emotion research (i.e., the appraisal model of emotion).

ARTICLE UPDATE - Beyond fear: rapid spatial orienting toward positive emotional stimuli.

Brosch T, Sander D, Pourtois G, Scherer KR.

Psychological Science, 19, 362-370

There is much empirical evidence for modulation of attention by negative-particularly fear-relevant-emotional stimuli. This modulation is often explained in terms of a fear module. Appraisal theories of emotion posit a more general mechanism, predicting attention capture by stimuli that are relevant for the needs and goals of the organism, regardless of valence. To examine the brain-activation patterns underlying attentional modulation, we recorded event-related potentials from 20 subjects performing a dot-probe task in which the cues were fear-inducing and nurturance-inducing stimuli (i.e., anger faces and baby faces). Highly similar validity modulation was found for the P1 time-locked to target onset, indicating early attentional capture by both positive and negative emotional stimuli. Topographic segmentation analysis and source localization indicate that the same amplification process is involved whether attention orienting is triggered by negative, fear-relevant stimuli or positive, nurturance-relevant stimuli. These results confirm that biological relevance, and not exclusively fear, produces an automatic spatial orienting toward the location of a stimulus.

Monday, April 07, 2008

ARTICLE UPDATE - Affective incoherence: When affective concepts and embodied reactions clash.

Centerbar DB, Schnall S, Clore GL, Garvin ED.

Journal of Personality and Social Psychology, 94, 560-578

In five studies, the authors examined the effects on cognitive performance of coherence and incoherence between conceptual and experiential sources of affective information. The studies crossed the priming of happy and sad concepts with affective experiences. In different experiments, these included approach or avoidance actions, happy or sad feelings, and happy or sad expressive behaviors. In all studies, coherence between affective concepts and affective experiences led to better recall of a story than did affective incoherence. The authors suggest that the experience of such experiential affective cues serves as evidence of the appropriateness of affective concepts that come to mind. The results suggest that affective coherence has epistemic benefits and that incoherence is costly in terms of cognitive performance.

ARTICLE UPDATE - Selective Attention to Affective Value Alters How the Brain Processes Olfactory Stimuli.

Rolls ET, Grabenhorst F, Margot C, da Silva MA, Velazco MI.

Journal of Cognitive Neuroscience, in press

How does selective attention to affect influence sensory processing? In an functional magnetic resonance imaging investigation, when subjects were instructed to remember and rate the pleasantness of a jasmin odor, activations were greater in the medial orbito-frontal and pregenual cingulate cortex than when subjects were instructed to remember and rate the intensity of the odor. When the subjects were instructed to remember and rate the intensity, activations were greater in the inferior frontal gyrus. These top-down effects occurred not only during odor delivery but started in a preparation period after the instruction before odor delivery, and continued after termination of the odor in a short-term memory period. Thus, depending on the context in which odors are presented and whether affect is relevant, the brain prepares itself, responds to, and remembers an odor differently. These findings show that when attention is paid to affective value, the brain systems engaged to prepare for, represent, and remember a sensory stimulus are different from those engaged when attention is directed to the physical properties of a stimulus such as its intensity. This differential biasing of brain regions engaged in processing a sensory stimulus depending on whether the cognitive demand is for affect-related versus more sensory-related processing may be an important aspect of cognition and attention. This has many implications for understanding the effects not only of olfactory but also of other sensory stimuli.

ARTICLE UPDATE - Working Memory for Social Cues Recruits Orbitofrontal Cortex and Amygdala: A Functional Magnetic Resonance Imaging Study of Delayed M

Lopresti ML, Schon K, Tricarico MD, Swisher JD, Celone KA, Stern CE.

The Journal of Neuroscience, 28, 3718-3728.

During everyday interactions, we continuously monitor and maintain information about different individuals and their changing emotions in memory. Yet to date, working memory (WM) studies have primarily focused on mechanisms for maintaining face identity, but not emotional expression, and studies investigating the neural basis of emotion have focused on transient activity, not delay related activity. The goal of this functional magnetic resonance imaging study was to investigate WM for two critical social cues: identity and emotion. Subjects performed a delayed match-to-sample task that required them to match either the emotional expression or the identity of a face after a 10 s delay. Neuroanatomically, our predictions focused on the orbitofrontal cortex (OFC) and the amygdala, as these regions have previously been implicated in emotional processing and long-term memory, and studies have demonstrated sustained OFC and medial temporal lobe activity during visual WM. Consistent with previous studies, transient activity during the sample period representing emotion and identity was found in the superior temporal sulcus and inferior occipital cortex, respectively. Sustained delay-period activity was evident in OFC, amygdala, and hippocampus, for both emotion and identity trials. These results suggest that, although initial processing of emotion and identity is accomplished in anatomically segregated temporal and occipital regions, sustained delay related memory for these two critical features is held by the OFC, amygdala and hippocampus. These regions share rich connections, and have been shown previously to be necessary for binding features together in long-term memory. Our results suggest a role for these regions in active maintenance as well.

Friday, March 28, 2008

ARTICLE UPDATE - The neurophysiological bases of emotion: An fMRI study of the affective circumplex using emotion-denoting words.

Posner J, Russell JA, Gerber A, Gorman D, Colibazzi T, Yu S, Wang Z, Kangarlu A, Zhu H, Peterson BS.

Human Brain Mapping, in press

Objective: We aimed to study the neural processing of emotion-denoting words based on a circumplex model of affect, which posits that all emotions can be described as a linear combination of two neurophysiological dimensions, valence and arousal. Based on the circumplex model, we predicted a linear relationship between neural activity and incremental changes in these two affective dimensions. Methods: Using functional magnetic resonance imaging, we assessed in 10 subjects the correlations of BOLD (blood oxygen level dependent) signal with ratings of valence and arousal during the presentation of emotion-denoting words. Results: Valence ratings correlated positively with neural activity in the left insular cortex and inversely with neural activity in the right dorsolateral prefrontal and precuneus cortices. The absolute value of valence ratings (reflecting the positive and negative extremes of valence) correlated positively with neural activity in the left dorsolateral and medial prefrontal cortex (PFC), dorsal anterior cingulate cortex, posterior cingulate cortex, and right dorsal PFC, and inversely with neural activity in the left medial temporal cortex and right amygdala. Arousal ratings and neural activity correlated positively in the left parahippocampus and dorsal anterior cingulate cortex, and inversely in the left dorsolateral PFC and dorsal cerebellum. Conclusion: We found evidence for two neural networks subserving the affective dimensions of valence and arousal. These findings clarify inconsistencies from prior imaging studies of affect by suggesting that two underlying neurophysiological systems, valence and arousal, may subserve the processing of affective stimuli, consistent with the circumplex model of affect.

ARTICLE UPDATE - Should Persuasion Be Affective or Cognitive? The Moderating Effects of Need for Affect and Need for Cognition.

Haddock G, Maio GR, Arnold K, Huskinson T.

ersonality and Social Psychology Bulletin, in press

Three experiments tested the hypothesis that need for affect and need for cognition influence receptivity to affect-and cognition-based persuasive messages. Experiment 1 found that an affective message elicited more positive attitudes among individuals high in need for affect and low in need for cognition, whereas a cognitive message elicited more positive attitudes among individuals low in need for affect and high in need for cognition. Experiment 2 found that individual differences in need for affect influenced receptivity to an affect-based (but not cognition-based) message, whereas individual differences in need for cognition influenced receptivity to a cognition-based (but not affect-based) message. Experiment 3 found that individual differences in need for affect were associated with increased recognition of information from an affect-based (but not cognition-based) message, whereas individual differences in need for cognition were associated with increased recognition of information from a cognition-based (but not affect-based) message. Overall, the studies point to the importance of individual differences in need for affect and need for cognition in understanding how individuals respond to different types of persuasive messages.

ARTICLE UPDATE - Disconnecting force from money: effects of basal ganglia damage on incentive motivation.

Schmidt L, d'Arc BF, Lafargue G, Galanaud D, Czernecki V, Grabli D, Schüpbach M, Hartmann A, Lévy R, Dubois B, Pessiglione M.

Brain, in press

Bilateral basal ganglia lesions have been reported to induce a particular form of apathy, termed auto-activation deficit (AAD), principally defined as a loss of self-driven behaviour that is reversible with external stimulation. We hypothesized that AAD reflects a dysfunction of incentive motivation, a process that translates an expected reward (or goal) into behavioural activation. To investigate this hypothesis, we designed a behavioural paradigm contrasting an instructed (externally driven) task, in which subjects have to produce different levels of force by squeezing a hand grip, to an incentive (self-driven) task, in which subjects can win, depending on their hand grip force, different amounts of money. Skin conductance was simultaneously measured to index affective evaluation of monetary incentives. Thirteen AAD patients with bilateral striato-pallidal lesions were compared to thirteen unmedicated patients with Parkinson's; disease (PD), which is characterized by striatal dopamine depletion and regularly associated with apathy. AAD patients did not differ from PD patients in terms of grip force response to external instructions or skin conductance response to monetary incentives. However, unlike PD patients, they failed to distinguish between monetary incentives in their grip force. We conclude that bilateral striato-pallidal damage specifically disconnects motor output from affective evaluation of potential rewards.

ARTICLE UDPATE - Affective incoherence: When affective concepts and embodied reactions clash.

Centerbar DB, Schnall S, Clore GL, Garvin ED.

Journal of Personality and Social Psychology, 94, 560-578.

In five studies, the authors examined the effects on cognitive performance of coherence and incoherence between conceptual and experiential sources of affective information. The studies crossed the priming of happy and sad concepts with affective experiences. In different experiments, these included approach or avoidance actions, happy or sad feelings, and happy or sad expressive behaviors. In all studies, coherence between affective concepts and affective experiences led to better recall of a story than did affective incoherence. The authors suggest that the experience of such experiential affective cues serves as evidence of the appropriateness of affective concepts that come to mind. The results suggest that affective coherence has epistemic benefits and that incoherence is costly in terms of cognitive performance.

ARTICLE UPDATE - Rapid interactions between the ventral visual stream and emotion-related structures rely on a two-pathway architecture.

Rudrauf D, David O, Lachaux JP, Kovach CK, Martinerie J, Renault B, Damasio A.

The Journal of Neuroscience, 28, 2793-2803

Visual attention can be driven by the affective significance of visual stimuli before full-fledged processing of the stimuli. Two kinds of models have been proposed to explain this phenomenon: models involving sequential processing along the ventral visual stream, with secondary feedback from emotion-related structures ("two-stage models"); and models including additional short-cut pathways directly reaching the emotion-related structures ("two-pathway models"). We tested which type of model would best predict real magnetoencephalographic responses in subjects presented with arousing visual stimuli, using realistic models of large-scale cerebral architecture and neural biophysics. The results strongly support a "two-pathway" hypothesis. Both standard models including the retinotectal pathway and nonstandard models including cortical-cortical long-range fasciculi appear plausible.

ARTICLE UPDATE - Beyond Conventional Event-related Brain Potential (ERP): Exploring the Time-course of Visual Emotion Processing Using Topographic and

Pourtois G, Delplanque S, Michel C, Vuilleumier P.

Brain Topography, in press

Recent technological advances with the scalp EEG methodology allow researchers to record electric fields generated in the human brain using a large number of electrodes or sensors (e.g. 64-256) distributed over the head surface (multi-channel recording). As a consequence, such high-density ERP mapping yields fairly dense ERP data sets that are often hard to analyze comprehensively or to relate straightforwardly to specific cognitive or emotional processes, because of the richness of the recorded signal in both the temporal (millisecond time-resolution) and spatial (multidimensional topographic information) domains. Principal component analyses (PCA) and topographic analyses (combined with distributed source localization algorithms) have been developed and successfully used to deal with this complexity, now offering powerful alternative strategies for data-driven analyses in complement to more traditional ERP analyses based on waveforms and peak measures. In this paper, we first briefly review the basic principles of these approaches, and then describe recent ERP studies that illustrate how they can inform about the precise spatio-temporal dynamic of emotion processing. These studies show that the perception of emotional visual stimuli may produce both quantitative and qualitative changes in the electric field configuration recorded at the scalp level, which are not apparent when using conventional ERP analyses. Additional information gained from these approaches include the identification of a sequence of successive processing stages that may not fully be reflected in ERP waveforms only, and the segregation of multiple or partly overlapping neural events that may be blended within a single ERP waveform. These findings highlight the added value of such alternative analyses when exploring the electrophysiological manifestations of complex and distributed mental functions, as for instance during emotion processing.

ARTICLE UPDATE - Emotion Processing in the Visual Brain: A MEG Analysis.

Peyk P, Schupp HT, Elbert T, Junghöfer M.

Brain Topography, in press

Recent functional magnetic resonance imaging (fMRI) and event-related brain potential (ERP) studies provide empirical support for the notion that emotional cues guide selective attention. Extending this line of research, whole head magneto-encephalogram (MEG) was measured while participants viewed in separate experimental blocks a continuous stream of either pleasant and neutral or unpleasant and neutral pictures, presented for 330 ms each. Event-related magnetic fields (ERF) were analyzed after intersubject sensor coregistration, complemented by minimum norm estimates (MNE) to explore neural generator sources. Both streams of analysis converge by demonstrating the selective emotion processing in an early (120-170 ms) and a late time interval (220-310 ms). ERF analysis revealed that the polarity of the emotion difference fields was reversed across early and late intervals suggesting distinct patterns of activation in the visual processing stream. Source analysis revealed the amplified processing of emotional pictures in visual processing areas with more pronounced occipito-parieto-temporal activation in the early time interval, and a stronger engagement of more anterior, temporal, regions in the later interval. Confirming previous ERP studies showing facilitated emotion processing, the present data suggest that MEG provides a complementary look at the spread of activation in the visual processing stream.

ARTICLE UPDATE - Neuronal Processes Involved in Subjective Feeling Emergence: Oscillatory Activity During an Emotional Monitoring Task.

Dan Glauser ES, Scherer KR.

Brain Topography, in press

Subjective feeling, defined as the conscious experience of emotion and measured by self-report, is generally used as a manipulation check in studying emotional processes, rather than being the primary focus of research. In this paper, we report a first investigation into the processes involved in the emergence of a subjective feeling. We hypothesized that the oscillatory brain activity presumed to underlie the emergence of a subjective feeling can be measured by electroencephalographic (EEG) frequency band activity, similar to what has been shown in the literature for the conscious representation of objects. Emotional reactions were induced in participants using static visual stimuli. Episodes for which participants reported a subjective feeling were compared to those that did not lead to a conscious emotional experience, in order to identify potential differences between these two kinds of reactions at the oscillatory level. Discrete wavelet transforms of the EEG signal in gamma (31-63 Hz) and beta (15-31 Hz) bands showed significant differences between these two types of reactions. In addition, whereas beta band activities were widely distributed, differences in gamma band activity were predominantly observed in the frontal and prefrontal regions. The results are interpreted and discussed in terms of the complexity of the processes required to perform the affective monitoring task. It is suggested that future work on coherent mental representation of multimodal reaction patterns leading to the emergence of conscious emotional experience should include modifications in the time window examined and an extension of the frequency range to be considered.

Friday, March 14, 2008

ARTICLE UPDATE - Distinct effects of attention and affect on pain perception and somatosensory evoked potentials.

Kenntner-Mabiala R, Andreatta M, Wieser MJ, Mühlberger A, Pauli P.

Biological Psychology, in press

The influence of affect and attention on sensory and affective pain as well as on somatosensory evoked potentials in response to painful and nonpainful electrical stimuli was investigated in a single experimental design. Affect was induced by pictures from the International Affective Picture System; attention was manipulated by asking participants to focus attention either on the pictures or on the electrical stimuli. Sensory and affective pain ratings were generally lower during exposure to positive compared to negative and neutral pictures. Attention modulated only sensory pain ratings with lower ratings with an attention focus on pictures than with an attention focus on sensory pain. The N150 was modulated by picture valence, the P260 by picture arousal. Furthermore, the P260 was modulated by attention with highest amplitudes with an attention focus on the stimulus intensity. This study provides neurophysiological evidence that attention and affect have distinct effects on pain processing.

ARTICLE UPDATE - Viewing emotionally arousing compared to neutral pictures is associated with differential electrophysiological activity in early ("ea

Rigoulot S, Delplanque S, Despretz P, Defoort-Dhellemmes S, Honoré J, Sequeira H.

Brain Topography, in press

Recent findings from event-related potentials (ERPs) studies provided strong evidence that cen- trally presented emotional pictures could be used to assess affective processing. Moreover, several studies showed that emotionally charged stimuli may automatically attract attention even if these are not consciously identified. Indeed, such perceptive conditions can be compared to those typical of the peripheral vision, particularly known to have low spatial resolution capacities. The aim of the present study was to characterize at behavioral and neural levels the impact of emotional visual scenes presented in peripheral vision. Eighteen participants were asked to categorize neutral and unpleasant pictures presented at central (0 degrees ) and peripheral eccentricities (-30 and +30 degrees ) while ERPs were recorded from 63 electrodes. ERPs were analysed by means of spatio-temporal principal component analyses (PCA) in order to evaluate influences of the emotional content on ERP components for each spatial position (central vs. peripheral). Main results highlight that affective modulation of early ERP components exists for both centrally and peripherally presented pictures. These findings suggest that, for far peripheral eccentricities as for central vision, the brain engages specific resources to process emotional information.

ARTICLE UPDATE - Affective Prime and Target Picture Processing: An ERP Analysis of Early and Late Interference Effects.

Flaisch T, Stockburger J, Schupp HT.

Brain Topography, in press

Viewing emotionally arousing compared to neutral pictures is associated with differential electrophysiological activity in early ("early posterior negativity", EPN), as well as later time-windows ("late positive potential", LPP). A previous study revealed that the EPN is reduced when the preceding prime picture was emotional. The present study explored whether sequential interference effects are specific for early processing stages or extend to later processing stages. Dense sensor ERPs were measured while subjects viewed a continuous stream of pleasant, neutral, and unpleasant pictures, presented for 660 ms each. Previous results were replicated in that emotional pictures were associated with enlarged EPN and LPP amplitudes compared to neutral pictures. Furthermore, the EPN to emotional and neutral pictures was reduced when preceded by pleasant prime pictures. The novel finding was that emotional compared to neutral prime pictures were associated with reduced LPP amplitudes to the subsequently presented picture irrespective of its emotional valence (pleasant, neutral, unpleasant). These results demonstrate sustained interference effects in serial picture presentations discussed within a framework of resource competition among successive pictures.

ARTICLE UPDATE - Immediate memory consequences of the effect of emotion on attention to pictures.

Talmi D, Anderson AK, Riggs L, Caplan JB, Moscovitch M.

Learning & Memory, 15, 172-182

Emotionally arousing stimuli are at once both highly attention grabbing and memorable. We examined whether emotional enhancement of memory (EEM) reflects an indirect effect of emotion on memory, mediated by enhanced attention to emotional items during encoding. We tested a critical prediction of the mediation hypothesis-that regions conjointly activated by emotion and attention would correlate with subsequent EEM. Participants were scanned with fMRI while they watched emotional or neutral pictures under instructions to attend to them a lot or a little, and were then given an immediate recognition test. A region in the left fusiform gyrus was activated by emotion, voluntary attention, and subsequent EEM. A functional network, different for each attention condition, connected this region and the amygdala, which was associated with emotion and EEM, but not with voluntary attention. These findings support an indirect cortical mediation account of immediate EEM that may complement a direct modulation model.

ARTICLE UPDATE - Distinguishing specific sexual and general emotional effects in fMRI-Subcortical and cortical arousal during erotic picture viewing.

Walter M, Bermpohl F, Mouras H, Schiltz K, Tempelmann C, Rotte M, Heinze HJ, Bogerts B, Northoff G.

Neuroimage, in press

Sexual activity involves excitement with high arousal and pleasure as typical features of emotions. Brain activations specifically related to erotic feelings and those related to general emotional processing are therefore hard to disentangle. Using fMRI in 21 healthy subjects (11 males and 10 females), we investigated regions that show activations specifically related to the viewing of sexually intense pictures while controlling for general emotional arousal (GEA) or pleasure. Activations in the ventral striatum and hypothalamus were found to be modulated by the stimulus' specific sexual intensity (SSI) while activations in the anterior cingulate cortex were associated with an interaction between sexual intensity and emotional valence. In contrast, activation in other regions like the dorsomedial prefrontal cortex, the mediodorsal thalamus and the amygdala was associated only with a general emotional component during sexual arousal. No differences were found in these effects when comparing females and males. Our findings demonstrate for the first time neural differentiation between emotional and sexual components in the neural network underlying sexual arousal.

ARTICLE UPDATE - Neuromagnetic Activity During Recognition of Emotional Pictures.

Kissler J, Hauswald A.

Brain Topography, in press

Recently studied [Symbol: see text]old' stimuli lead to larger frontal and parietal ERP responses than [Symbol: see text]new' stimuli. The present experiment investigated the neuromagnetic correlates (MEG) of this [Symbol: see text]old-new' effect and its modulation by emotional stimulus content. Highly arousing pleasant, highly arousing unpleasant and un-arousing neutral photographs were presented to the participants with the instruction to memorize them. They were later re-presented together with new photographs in an old-new decision task. In line with previous ERP studies, a long-lasting old-new effect (350-700 ms) was found. Independently, an emotion effect also occurred, as reflected in a, particularly left temporal, activity increase for emotional pictures between 450 and 580 ms. Moreover, only for the pleasant pictures did the early part of the old-new effect, which is thought to reflect familiarity based recognition processes, interact with picture content: The old-new effect for pleasant pictures in frontal regions was larger than the one for neutral or unpleasant pictures between 350 and 450 ms. In parallel, subjects' responses were accelerated towards and biased in favour of classifying pleasant pictures as old. However, when false alarm rate was taken into account, there was no significant effect of emotional content on recognition accuracy. In sum, this MEG study demonstrates an effect of particularly pleasant emotional content on recognition memory which may be mediated by a familiarity based process.

Friday, March 07, 2008

ARTICLE UPDATE - Incidental encoding of emotional pictures: Affective bias studied through event related brain potentials.

Tapia M, Carretié L, Sierra B, Mercado F.

International Journal of Psychophysiology, in press

Emotional stimuli are better remembered than neutral stimuli. Most of the studies taking into account this emotional bias refer to explicit memory, use behavioral measures of the recall and predict better recall of negative stimuli. The few studies taking into account implicit memory and the valence emotional dimension are inconclusive on the effect of the stimulus' emotional valence. In the present study, 120 pictures (30 positive, 30 negative, 30 relaxing and 30 neutral) were shown to, and assessed by, 28 participants (study phase). Subsequently, event related brain potentials (ERPs) were recorded during the presentation of 120 new (shown for the first time) and 120 old (already shown in the study phase) pictures (test phase). No explicit instructions or clues related to recovery were given to participants, and a distractor task was employed, in order to maintain implicit the memory assessment. As expected from other studies' data, our results showed that old stimuli elicited an enhanced late positive component 450 ms after stimulus onset (repetition effect). Moreover, this effect was modulated by the stimuli's emotional valence, since the most positively valenced stimuli were associated with a decreased repetition effect with respect to the most negatively valenced stimuli. This effect was located at ventromedial prefrontal cortex. These results suggest the existence of a valence-mediated bias in implicit memory.

ARTICLE UPDATE - Affective neuroscience of pleasure: reward in humans and animals.

Berridge KC, Kringelbach ML.

Psychopharmacology, in press

INTRODUCTION: Pleasure and reward are generated by brain circuits that are largely shared between humans and other animals. DISCUSSION: Here, we survey some fundamental topics regarding pleasure mechanisms and explicitly compare humans and animals. CONCLUSION: Topics surveyed include liking, wanting, and learning components of reward; brain coding versus brain causing of reward; subjective pleasure versus objective hedonic reactions; roles of orbitofrontal cortex and related cortex regions; subcortical hedonic hotspots for pleasure generation; reappraisals of dopamine and pleasure-electrode controversies; and the relation of pleasure to happiness.

ARTICLE UPDATE - Valuating other people's emotional face expression: A combined functional magnetic resonance imaging and electroencephalography study

Seitz RJ, Schäfer R, Scherfeld D, Friederichs S, Popp K, Wittsack HJ, Azari NP, Franz M.

Neuroscience, in press

Reading the facial expression of other people is a fundamental skill for social interaction. Human facial expressions of emotions are readily recognized but may also evoke the same experiential emotional state in the observer. We used event-related functional magnetic resonance imaging and multi-channel electroencephalography to determine in 14 right-handed healthy volunteers (29+/-6 years) which brain structures mediate the perception of such a shared experiential emotional state. Statistical parametric mapping showed that an area in the dorsal medial frontal cortex was specifically activated during the perception of emotions that reflected the seen happy and sad emotional face expressions. This area mapped to the pre-supplementary motor area which plays a central role in control of behavior. Low resolution brain electromagnetic tomography-based analysis of the encephalographic data revealed that the activation was detected 100 ms after face presentation onset lasting until 740 ms. Our observation substantiates recently emerging evidence suggesting that the subjective perception of an experiential emotional state-empathy-is mediated by the involvement of the dorsal medial frontal cortex.

ARTICLE UPDATE - Emotional valence and arousal interact in attentional control.

Jefferies LN, Smilek D, Eich E, Enns JT.

Psychological Science, 19, 290-295

A recent study demonstrated that observers' ability to identify targets in a rapid visual sequence was enhanced when they simultaneously listened to happy music. In the study reported here, we examined how the emotion-attention relationship is influenced by changes in both mood valence (negative vs. positive) and arousal (low vs. high). We used a standard induction procedure to generate calm, happy, sad, and anxious moods in participants. Results for an attentional blink task showed no differences in first-target accuracy, but second-target accuracy was highest for participants with low arousal and negative affect (sad), lowest for those with strong arousal and negative affect (anxious), and intermediate for those with positive affect regardless of their arousal (calm, happy). We discuss implications of this valence-arousal interaction for the control of visual attention.

Friday, February 29, 2008

ARTICLE UPDATE - Seeing the pain of others while being in pain: A laser-evoked potentials study.

Valeriani M, Betti V, Le Pera D, De Armas L, Miliucci R, Restuccia D, Avenanti A, Aglioti SM.

Neuroimage, in press

Seeing actions, emotions and feelings of other individuals may activate resonant mechanisms that allow the empathic understanding of others' states. Being crucial for implementing pro-social behaviors, empathy is considered as inherently altruistic. Here we explored whether the personal experience of pain make individuals less inclined to share others' pain. We used laser-evoked potentials (LEPs) to explore whether observation of painful or non-noxious stimuli delivered to a stranger model induced any modulation in the pain system of onlookers who were suffering from pain induced by the laser stimuli. After LEPs recording, participants rated intensity and unpleasantness of the laser pain, and of the pain induced by the movie in themselves and in the model. Mere observation of needles penetrating the model's hand brought about a specific reduction of the N1/P1 LEP component, related to the activation of somatic nodes of the pain matrix. Such reduction is stronger in onlookers who rated the pain intensity induced by the pain movie as higher in themselves and lower in the model. Conversely, the N2a-P2 component, supposedly associated to affective pain qualities, did not show any specific modulation during observation of others' pain. Thus, viewing 'flesh and bone' pain in others specifically modulates neural activity in the pain matrix sensory node. Moreover, this socially-derived inhibitory effect is correlated with the intensity of the pain attributed to self rather than to others suggesting that being in pain may bias the empathic relation with stranger models towards self-centred instead than other-related stances.

ARTICLE UPDATE - Understanding the Role of Emotion in Sense-making. A Semiotic Psychoanalytic Oriented Perspective.

Salvatore S, Venuleo C.

Integrative Psychological and Behavioral Science, 42, 32-46

We propose a model of emotion grounded on Ignacio Matte Blanco's theory of the unconscious. According to this conceptualization, emotion is a generalized representation of the social context actors are involved in. We discuss how this model can help to better understand the sensemaking processes. For this purpose we present a hierarchical model of sensemaking based on the distinction between significance-the content of the sign-and sense-the psychological value of the act of producing the sign in the given contingence of the social exchange. According to this model, emotion categorization produces the frame of sense regulating the interpretation of the sense of the signs, therefore creating the psychological value of the sensemaking.

ARTICLE UPDATE - The power of the word may reside in the power of affect.

Panksepp J.

Integrative Psychological and Behavioral Science, 42, 47-55

This commentary on Dan Shanahan's, A New View of Language, Emotion and the Brain, basically agrees with an emotion-based view of the evolutionary and developmental basis of language acquisition. It provides a supplementary neuroscience perspective that is more deeply affective and epigenetic in the sense that all claims about neocortically-based language modules need to be tempered by the existing genetic evidence as well as the robust neuroscience evidence that the cortex resembles random-access-memory space, a tabula rasa upon which epigenetic and learning processes create functional networks. The transition from non-linguistic creatures to linguistic ones may have required the conjunction of social-affective brain mechanisms, morphological changes in the articulatory apparatus, an abundance of cross-modal cortical processing ability, and the initial urge to communicate in coordinate prosodic gestural and vocal ways, which may have been more poetic and musical than current propositional language. There may be no language instinct that is independent of these evolutionary pre-adaptations.

ARTICLE UPDATE - Differential effects of object-based attention on evoked potentials to fearful and disgusted faces.

Isabel M. Santos, Jaime Iglesias, Ela I. Olivares and Andrew W. Young

Neuropsychologia, in press

Event-related potentials (ERPs) were used to investigate the role of attention on the processing of facial expressions of fear and disgust. Stimuli consisted of overlapping pictures of a face and a house. Participants had to monitor repetitions of faces or houses, in separate blocks of trials, so that object-based attention was manipulated while spatial attention was kept constant. Faces varied in expression and could be either fearful or neutral (in the fear condition) or disgusted or neutral (in the disgust condition). When attending to faces, participants were required to signal repetitions of the same person, with the facial expressions being completely irrelevant to the task. Different effects of selective attention and different patterns of brain activity were observed for faces with fear and disgust expressions. Results indicated that the perception of fear from faces is gated by selective attention at early latencies, whereas a sustained positivity for fearful faces compared to neutral faces emerged around 160ms at central-parietal sites, independent of selective attention. In the case of disgust, ERP differences began only around 160ms after stimulus onset, and only after 480ms was the perception of disgust modulated by attention allocation. Results are interpreted in terms of different neural mechanisms for the perception of fear and disgust and related to the functional significance of these two emotions for the survival of the organism.

Thursday, February 21, 2008

ARTICLE UPDATE - Emotional scenes in peripheral vision: Selective orienting and gist processing, but not content identification.

Calvo MG, Nummenmaa L, Hyönä J.

Emotion, 8, 68-80

Emotional-neutral pairs of visual scenes were presented peripherally (with their inner edges 5.2 degrees away from fixation) as primes for 150 to 900 ms, followed by a centrally presented recognition probe scene, which was either identical in specific content to one of the primes or related in general content and affective valence. Results indicated that (a) if no foveal fixations on the primes were allowed, the false alarm rate for emotional probes was increased; (b) hit rate and sensitivity (A') were higher for emotional than for neutral probes only when a fixation was possible on only one prime; and (c) emotional scenes were more likely to attract the first fixation than neutral scenes. It is concluded that the specific content of emotional or neutral scenes is not processed in peripheral vision. Nevertheless, a coarse impression of emotional scenes may be extracted, which then leads to selective attentional orienting or--in the absence of overt attention--causes false alarms for related probes.

ARTICLE UPDATE - Affective learning increases sensitivity to graded emotional faces.

Lim SL, Pessoa L.

Emotion, 8, 96-103

How does the affective significance of emotional faces affect perceptual decisions? We manipulated affective significance by pairing 100% fearful faces with aversive electrical stimulation and hypothesized that increasing the significance of a stimulus via its prior history would lead to enhanced processing. After fear conditioning, participants viewed graded emotional faces that ranged from neutral to fearful. Faces were shown either in a color that was previously paired with shock or a color not paired with shock during conditioning. Increases in the frequency of "fearful" responses for faces shown in the shock-paired color were most robust for faces at intermediate intensity levels (40-60% fearful). Psychometric fits to the data revealed significant increased sensitivity for shock-paired relative to unpaired faces. Thus, despite identical physical features for shock-paired and unpaired stimuli (aside from the color, which was counterbalanced), more frequent (and faster) "fearful" responses were made when participants viewed affectively significant stimuli.

ARTICLE UPDATE - Affective flexibility: evaluative processing goals shape amygdala activity.

Cunningham WA, Van Bavel JJ, Johnsen IR.

Psychological Science, 19, 152-160

Although early research implicated the amygdala in automatic processing of negative information, more recent research suggests that it plays a more general role in processing the motivational relevance of various stimuli, suggesting that the relation between valence and amygdala activation may depend on contextual goals. This study provides experimental evidence that the relation between valence and amygdala activity is dynamically modulated by evaluative goals. During functional magnetic resonance imaging, participants evaluated the positive, negative, or overall (positive plus negative) aspects of famous people. When participants were providing overall evaluations, both positive and negative names were associated with amygdala activation. When they were evaluating positivity, positive names were associated with amygdala activity, and when they were evaluating negativity, negative names were associated with amygdala activity. Evidence for a negativity bias was found; modulation was more pronounced for positive than for negative information. These data suggest that the amygdala flexibly processes motivationally relevant evaluative information in accordance with current processing goals, but processes negative information less flexibly than positive information.

ARTICLE UPDATE - Neural activities for negative priming with affective stimuli: An fMRI study.

Leung KK, Lee TM, Xiao Z, Wang Z, Zhang JX, Yip PS, Li LS.

Neuropsychology, in press

Negative priming refers to the slowing down in reaction time to a stimulus that is either the same as, or related to, a distracting stimulus that has been ignored by people in an immediately preceding trial. It can be used as an index to examine the extent to which people are able to disengage attention or even ignore a distracting stimulus. In this fMRI study, with healthy Mandarin-speaking Chinese participants, we replicated the basic negative priming effect with affectively neutral words. Negative priming was associated with increased activities in the anterior cingulate cortex and the insula, a result that supports the inhibition account of negative priming. We observed that the negative priming effect was attenuated by negative affective words, relative to neutral words, suggesting that subjects' inhibition of negative information was compromised. Such attenuation of negative priming by negative affective words was associated with increased activities in the ventrolateral and medial frontal regions, the hippocampus, and supplementary motor areas. These observations indicate that specific frontal and subcortical regions take part in attention orientation toward negative-affect information.

ARTICLE UPDATE - The pupil as a measure of emotional arousal and autonomic activation.

Bradley MM, Miccoli L, Escrig MA, Lang PJ.

Psychophysiology, in press

Pupil diameter was monitored during picture viewing to assess effects of hedonic valence and emotional arousal on pupillary responses. Autonomic activity (heart rate and skin conductance) was concurrently measured to determine whether pupillary changes are mediated by parasympathetic or sympathetic activation. Following an initial light reflex, pupillary changes were larger when viewing emotionally arousing pictures, regardless of whether these were pleasant or unpleasant. Pupillary changes during picture viewing covaried with skin conductance change, supporting the interpretation that sympathetic nervous system activity modulates these changes in the context of affective picture viewing. Taken together, the data provide strong support for the hypothesis that the pupil's response during affective picture viewing reflects emotional arousal associated with increased sympathetic activity.

ARTICLE UPDATE - The use of aftereffects in the study of relationships among emotion categories.

Rutherford MD, Chattha HM, Krysko KM.

Journal of Experimental Psychology: Human Perception & Performance, 34, 27-40

The perception of visual aftereffects has been long recognized, and these aftereffects reveal a relationship between perceptual categories. Thus, emotional expression aftereffects can be used to map the categorical relationships among emotion percepts. One might expect a symmetric relationship among categories, but an evolutionary, functional perspective predicts an asymmetrical relationship. In a series of 7 experiments, the authors tested these predictions. Participants fixated on a facial expression, then briefly viewed a neutral expression, then reported the apparent facial expression of the 2nd image. Experiment 1 revealed that happy and sad are opposites of one another; each evokes the other as an aftereffect. The 2nd and 3rd experiments reveal that fixating on any negative emotions yields an aftereffect perceived as happy, whereas fixating on a happy face results in the perception of a sad aftereffect. This suggests an asymmetric relationship among categories. Experiments 4-7 explored the mechanism driving this effect. The evolutionary and functional explanations for the category asymmetry are discussed.

ARTICLE UPDATE - The emotional memory effect: differential processing or item distinctiveness?

Schmidt SR, Saari B.

Memory & Cognition, 35, 1905-1916

A color-naming task was followed by incidental free recall to investigate how emotional words affect attention and memory. We compared taboo, nonthreatening negative-affect, and neutral words across three experiments. As compared with neutral words, taboo words led to longer color-naming times and better memory in both within- and between-subjects designs. Color naming of negative-emotion nontaboo words was slower than color naming of neutral words only during block presentation and at relatively short interstimulus intervals (ISIs). The nontaboo emotion words were remembered better than neutral words following blocked and random presentation and at both long and short ISIs, but only in mixed-list designs. Our results support multifactor theories of the effects of emotion on attention and memory. As compared with neutral words, threatening stimuli received increased attention, poststimulus elaboration, and benefit from item distinctiveness, whereas nonthreatening emotional stimuli benefited only from increased item distinctiveness.

ARTICLE UPDATE - The automaticity of emotion recognition.

Tracy JL, Robins RW.

Emotion, 8, 81-95

Evolutionary accounts of emotion typically assume that humans evolved to quickly and efficiently recognize emotion expressions because these expressions convey fitness-enhancing messages. The present research tested this assumption in 2 studies. Specifically, the authors examined (a) how quickly perceivers could recognize expressions of anger, contempt, disgust, embarrassment, fear, happiness, pride, sadness, shame, and surprise; (b) whether accuracy is improved when perceivers deliberate about each expression's meaning (vs. respond as quickly as possible); and (c) whether accurate recognition can occur under cognitive load. Across both studies, perceivers quickly and efficiently (i.e., under cognitive load) recognized most emotion expressions, including the self-conscious emotions of pride, embarrassment, and shame. Deliberation improved accuracy in some cases, but these improvements were relatively small. Discussion focuses on the implications of these findings for the cognitive processes underlying emotion recognition.

ARTICLE UPDATE - Modulations of the electrophysiological response to pleasant stimuli by cognitive reappraisal.

Krompinger JW, Moser JS, Simons RF.

Emotion, 8, 132-137

Research indicates that individuals successfully regulate their emotions to negatively valenced stimuli using cognitive, antecedent-focused techniques (cf. Gross, 1998). Event-related potential studies have elucidated candidate neural correlates, particularly modulations of the late positive potential (LPP) to index emotion regulation processes. The present study attempted to extend prior demonstrations of emotion regulation effects on the LPP to the domain of positively valenced stimuli. Twenty participants completed a blocked emotion regulation task: The first block consisted of passively viewing pleasant and neutral pictures, whereas the last two blocks consisted of either decreasing or increasing emotions to pleasant pictures. Results replicated our previous findings with negatively valenced stimuli, demonstrating an attenuated LPP during decrease instructions and no effect of increase instructions. Modulation of the ERP as a function of instruction was most prominent during the positive-going slow-wave time window of the LPP, indicating that attentional resources allocated to the perceptual processing of pleasant stimuli may be manipulated using emotion regulation strategies.

Tuesday, February 12, 2008

ARTICLE UPDATE - Learning affective values for faces is expressed in amygdala and fusiform gyrus

Predrag Petrovic, Raffael Kalisch, Mathias Pessiglione, Tania Singer and Raymond J. Dolan

Social Cognitive and Affective Neuroscience, in press

To monitor the environment for social threat humans must build affective evaluations of others. These evaluations are malleable and to a high degree shaped by responses engendered by specific social encounters. The precise neuronal mechanism by which these evaluations are constructed is poorly understood. We tested a hypothesis that conjoint activity in amygdala and fusiform gyrus would correlate with acquisition of social stimulus value. We tested this using a reinforcement learning algorithm, Q-learning, that assigned values to faces as a function of a history of pairing, or not pairing, with aversive shocks. Behaviourally, we observed a correlation between conditioning induced changes in skin conductance response (SCR) and subjective ratings for likeability of faces. Activity in both amygdala and fusiform gyrus (FG) correlated with the output of the reinforcement learning algorithm parameterized by these ratings. In amygdala, this effect was greater for averted than direct gaze faces. Furthermore, learning-related activity change in these regions correlated with SCR and subjective ratings. We conclude that amygdala and fusiform encode affective value in a manner that closely approximates a standard computational solution to learning.

ARTICLE UPDATE - Electrophysiological correlates of spatial orienting towards angry faces: A source localization study

Diane L. Santesso, Alicia E. Meuret, Stefan G. Hofmann, Erik M. Mueller, Kyle G. Ratner, Etienne B. Roesch and Diego A. Pizzagalli

Neuropsychologia, in press

The goal of this study was to examine behavioral and electrophysiological correlates of involuntary orienting toward rapidly presented angry faces in non-anxious, healthy adults using a dot-probe task in conjunction with high-density event-related potentials and a distributed source localization technique. Consistent with previous studies, participants showed hypervigilance toward angry faces, as indexed by facilitated response time for validly cued probes following angry faces and an enhanced P1 component. An opposite pattern was found for happy faces suggesting that attention was directed toward the relatively more threatening stimuli within the visual field (neutral faces). Source localization of the P1 effect for angry faces indicated increased activity within the anterior cingulate cortex, possibly reflecting conflict experienced during invalidly cued trials. No modulation of the early C1 component was found for affect or spatial attention. Furthermore, the face-sensitive N170 was not modulated by emotional expression. Results suggest that the earliest modulation of spatial attention by face stimuli is manifested in the P1 component, and provide insights about mechanisms underlying attentional orienting toward cues of threat and social disapproval.

Tuesday, February 05, 2008

ARTICLE UPDATE - Does it look painful or disgusting? Ask your parietal and cingulate cortex.

Benuzzi F, Lui F, Duzzi D, Nichelli PF, Porro CA.

The Journal of Neuroscience, 28, 923-931

Looking at still images of body parts in situations that are likely to cause pain has been shown to be associated with activation in some brain areas involved in pain processing. Because pain involves both sensory components and negative affect, it is of interest to explore whether the visually evoked representations of pain and of other negative emotions overlap. By means of event-related functional magnetic resonance imaging, here we compare the brain areas recruited, in female volunteers, by the observation of painful, disgusting, or neutral stimuli delivered to one hand or foot. Several cortical foci were activated by the observation of both painful and disgusting video clips, including portions of the medial prefrontal cortex, anterior, mid-, and posterior cingulate cortex, left posterior insula, and right parietal operculum. Signal changes in perigenual cingulate and left anterior insula were linearly related to the perceived unpleasantness, when the individual differences in susceptibility to aversive stimuli were taken into account. Painful scenes selectively induced activation of left parietal foci, including the parietal operculum, the postcentral gyrus, and adjacent portions of the posterior parietal cortex. In contrast, brain foci specific for disgusting scenes were found in the posterior cingulate cortex. These data show both similarities and differences between the brain patterns of activity related to the observation of noxious or disgusting stimuli. Namely, the parietal cortex appears to be particularly involved in the recognition of noxious environmental stimuli, suggesting that areas involved in sensory aspects of pain are specifically triggered by observing noxious events.

ARTICLE UPDATE - The cognitive consequences of emotion regulation: An ERP investigation.

Deveney CM, Pizzagalli DA.

Psychophysiology, in press

Increasing evidence suggests that emotion regulation (ER) strategies modulate encoding of information presented during regulation; however, no studies have assessed the impact of cognitive reappraisal ER strategies on the processing of stimuli presented after the ER period. Participants in the present study regulated emotions to unpleasant pictures and then judged whether a word was negative or neutral. Electromyographic measures (corrugator supercilli) confirmed that individuals increased and decreased negative affect according to ER condition. Event-related potential analyses revealed smallest N400 amplitudes to negative and neutral words presented after decreasing unpleasant emotions and smallest P300 amplitudes to words presented after increasing unpleasant emotions whereas reaction time data failed to show ER modulations. Results are discussed in the context of the developing ER literature, as well as theories of emotional incongruity (N400) and resource allocation (P300).

ARTICLE UPDATE - Fearful faces selectively increase corticospinal motor tract excitability: A transcranial magnetic stimulation study.

Schutter DJ, Hofman D, Van Honk J.

Psychophysiology, in press

Fearful facial expressions are danger signals that rapidly trigger a cascade of neurobiological processes defensibly associated with action preparation. However, direct evidence for the activating effects of fearful facial expressions on the motor system is absent. The current transcranial magnetic stimulation (TMS) study investigated whether fearful facial expressions selectively increase corticospinal motor tract (CST) excitability. Focal TMS was applied over the left primary motor cortex during the exposure of fearful, happy, and neutral facial expressions in 12 healthy right-handed volunteers. Changes in CST excitability using the motor evoked potential (MEP) were recorded. Results showed significant selective increases in MEP to fearful facial expressions. These findings provide the first direct evidence for selective increases in CST excitability to threat and contribute to evolutionary views on emotion and action preparedness.