Friday, May 25, 2007

ARTICLE UPDATE - Fear and anxiety as separable emotions: An investigation of the revised reinforcement sensitivity theory of personality.

Perkins AM, Kemp SE, Corr PJ

Emotion, 7, 252-261

The Gray and McNaughton (2000) theory draws on a wide range of animal data to hypothesize that the emotions of fear and anxiety are separable. The authors tested their hypothesis in two studies. The first study examined associations between scores on questionnaire measures of fear, anxiety, and neuroticism; correlational analysis revealed that fear and anxiety are not interchangeable constructs. The second study examined associations between scores on questionnaire measures of fear/anxiety and performance in a military training setting; regression analysis revealed that fear captured significant variance in performance that was not shared with anxiety. These results imply that hypotheses derived from nonhuman animal data may hold important implications for understanding human emotion and motivation, especially in relation to fear and anxiety.

ARTICLE UPDATE - Garner interference reveals dependencies between emotional expression and gaze in face perception.

Graham R, Labar KS

Emotion, 7, 296-313

The relationship between facial expression and gaze processing was investigated with the Garner selective attention paradigm. In Experiment 1, participants performed expression judgments without interference from gaze, but expression interfered with gaze judgments. Experiment 2 replicated these results across different emotions. In both experiments, expression judgments occurred faster than gaze judgments, suggesting that expression was processed before gaze could interfere. In Experiments 3 and 4, the difficulty of the emotion discrimination was increased in two different ways. In both cases, gaze interfered with emotion judgments and vice versa. Furthermore, increasing the difficulty of the emotion discrimination resulted in gaze and expression interactions. Results indicate that expression and gaze interactions are modulated by discriminability. Whereas expression generally interferes with gaze judgments, gaze direction modulates expression processing only when facial emotion is difficult to discriminate.

ARTICLE UPDATE - Dissociable effects of conscious emotion regulation strategies on explicit and implicit memory.

Dillon DG, Ritchey M, Johnson BD, Labar KS.

Emotion, 7, 354-365

The authors manipulated emotion regulation strategies at encoding and administered explicit and implicit memory tests. In Experiment 1, participants used reappraisal to enhance and decrease the personal relevance of unpleasant and neutral pictures. In Experiment 2, decrease cues were replaced with suppress cues that directed participants to inhibit emotion-expressive behavior. Across experiments, using reappraisal to enhance the personal relevance of pictures improved free recall. By contrast, attempting to suppress emotional displays tended to impair recall, especially compared to the enhance condition. Using reappraisal to decrease the personal relevance of pictures had different effects depending on picture type. Paired with unpleasant pictures, the decrease cue tended to improve recall. Paired with neutral stimuli, the decrease cue tended to impair recall. Emotion regulation did not affect perceptual priming. Results highlight dissociable effects of emotion regulation on explicit and implicit memory, as well as dissociations between regulation strategies with respect to explicit memory.

Friday, May 18, 2007

ARTICLE UPDATE - Gaze fixations predict brain activation during the voluntary regulation of picture-induced negative affect.

Carien M. van Reekuma, Tom Johnstone, Heather L. Urry, Marchell E. Thurow, Hillary S. Schaefer, Andrew L. Alexander and Richard J. Davidson

NeuroImage, in press

Recent studies have identified a distributed network of brain regions thought to support cognitive reappraisal processes underlying emotion regulation in response to affective images, including parieto-temporal regions and lateral/medial regions of prefrontal cortex (PFC). A number of these commonly activated regions are also known to underlie visuospatial attention and oculomotor control, which raises the possibility that people use attentional redeployment rather than, or in addition to, reappraisal as a strategy to regulate emotion. We predicted that a significant portion of the observed variance in brain activation during emotion regulation tasks would be associated with differences in how participants visually scan the images while regulating their emotions. We recorded brain activation using fMRI and quantified patterns of gaze fixation while participants increased or decreased their affective response to a set of affective images. fMRI results replicated previous findings on emotion regulation with regulation differences reflected in regions of PFC and the amygdala. In addition, our gaze fixation data revealed that when regulating, individuals changed their gaze patterns relative to a control condition. Furthermore, this variation in gaze fixation accounted for substantial amounts of variance in brain activation. These data point to the importance of controlling for gaze fixation in studies of emotion regulation that use visual stimuli.

ARTICLE UPDATE - Attention control, memory updating, and emotion regulation temporarily reduce the capacity for executive control.

Schmeichel BJ.

Journal of Experimental Psychology: General, 136, 241-255.

This research tested the hypothesis that initial efforts at executive control temporarily undermine subsequent efforts at executive control. Four experiments revealed that controlling the focus of visual attention (Experiment 1), inhibiting predominant writing tendencies (Experiment 2), taking a working memory test (Experiment 3), or exaggerating emotional expressions (Experiment 4) undermined performance on subsequent tests of working memory span, reverse digit span, and response inhibition, respectively. The results supported a limited resource model of executive control and cast doubt on competing accounts based on mood, motivation, or task difficulty. Prior efforts at executive control are a significant contextual determinant of the operation of executive processes.

Tuesday, May 15, 2007

ARTICLE UPDATE - Visual presentation of phobic stimuli: Amygdala activation via an extrageniculostriate pathway?

Liesbet Goossens, Koen Schruers, Ronald Peeters, Eric Griez and Stefan Sunaert

Psychiatry Research: Neuroimaging, in press

In the present study, event-related functional magnetic resonance imaging (fMRI) was used to examine the neural correlates of phobic fear by exposing spider phobic subjects to a visual presentation of spiders. In contrast to control subjects, spider phobics showed significantly increased activation in the amygdala and the pulvinar nucleus of the thalamus on the basis of region of interest (ROI) analysis. Furthermore, voxelwise analysis revealed increased activation related to phobia-specific pictures bilaterally in the anterior cingulate cortex, the left insular cortex and bilaterally in the supplementary motor area. These findings confirm the involvement of the amygdala in the processing of phobia-relevant stimuli as found earlier in a recent study. Moreover, the thalamus findings support the involvement of an extrageniculostriate pathway in the process of phobic fear.

Friday, May 11, 2007

ARTICLE UPDATE - Brain, emotion and decision making: the paradigmatic example of regret

Giorgio Coricelli, Raymond J. Dolan, and Angela Sirigu

Trends in Cognitive Sciences, in press

Human decisions cannot be explained solely by rational imperatives but are strongly influenced by emotion. Theoretical and behavioral studies provide a sound empirical basis to the impact of the emotion of regret in guiding choice behavior. Recent neuropsychological and neuroimaging data have stressed the fundamental role of the orbitofrontal cortex in mediating the experience of regret. Functional magnetic resonance imaging data indicate that reactivation of activity within the orbitofrontal cortex and amygdala occurring during the phase of choice, when the brain is anticipating possible future consequences of decisions, characterizes the anticipation of regret. In turn, these patterns reflect learning based on cumulative emotional experience. Moreover, affective consequences can induce specific mechanisms of cognitive control of the choice processes, involving reinforcement or avoidance of the experienced behavior.

ARTICLE UPDATE - fMRI delineation of working memory for emotional prosody in the brain: Commonalities with the lexico-semantic emotion network

Rachel L.C. Mitchell

NeuroImage, in press

Decoding emotional prosody is crucial for successful social interactions, and continuous monitoring of emotional intent via prosody requires working memory. It has been proposed by Ross and others that emotional prosody cognitions in the right hemisphere are organized in an analogous fashion to propositional language functions in the left hemisphere. This study aimed to test the applicability of this model in the context of prefrontal cortex working memory functions. BOLD response data were therefore collected during performance of two emotional working memory tasks by participants undergoing fMRI. In the prosody task, participants identified the emotion conveyed in pre-recorded sentences, and working memory load was manipulated in the style of an N-back task. In the matched lexico-semantic task, participants identified the emotion conveyed by sentence content. Block-design neuroimaging data were analyzed parametrically with SPM5. At first, working memory for emotional prosody appeared to be right-lateralized in the PFC, however, further analyses revealed that it shared much bilateral prefrontal functional neuroanatomy with working memory for lexico-semantic emotion. Supplementary separate analyses of males and females suggested that these language functions were less bilateral in females, but their inclusion did not alter the direction of laterality. It is concluded that Ross et al.’s model is not applicable to prefrontal cortex working memory functions, that evidence that working memory cannot be subdivided in prefrontal cortex according to material type is increased, and that incidental working memory demands may explain the frontal lobe involvement in emotional prosody comprehension as revealed by neuroimaging studies.

Friday, May 04, 2007

ARTICLE UPDATE - A time-course analysis of attentional cueing by threatening scenes.

Koster EH, Crombez G, Verschuere B, Vanvolsem P, De Houwer J.

Experimental Psychology, 54, 161-171

Models of attention and emotion have assigned a special status to the processing of threatening information: Facilitated attentional capture by threat and its prioritized processing would allow for swift and adequate action to potentially dangerous stimuli. In four experiments, we examined the time-course of facilitated orienting of attention to threatening scenes in the exogenous cueing paradigm. Threat value and presentation duration of the cues were systematically varied. Facilitated attentional capture by threat was limited to highly threatening pictures presented for 100 ms. No attentional effects were observed with a 28 ms cue presentation duration. At slightly longer cue presentations, 200 ms and 500 ms, results indicated no and even reduced attentional capture by threat compared with neutral information. The present results provide support for the idea that threat facilitates fast attentional orienting to its location, followed by the inhibition of attention to threat.

Tuesday, May 01, 2007

ARTICLE UPDATE - Neural Correlates of Positive and Negative Emotion Regulation

Sang Hee Kim and Stephan Hamann

Journal of Cognitive Neuroscience, 19, 776-798

The ability to cope adaptively with emotional events by volitionally altering one's emotional reactions is important for psychological and physical health as well as social interaction. Cognitive regulation of emotional responses to aversive events engages prefrontal regions that modulate activity in emotion-processing regions such as the amygdala. However, the neural correlates of the regulation of positive emotions remain largely unexplored. We used event-related functional magnetic resonance imaging to examine the neural correlates of cognitively increasing and decreasing emotional reactions to positive and negative stimuli. Participants viewed negative, positive, and neutral pictures while attempting to increase, decrease, or not alter their emotional reactions. Subjective reactions were assessed via on-line ratings. Consistent with previous studies, increasing negative and positive emotion engaged primarily left-lateralized prefrontal regions, whereas decreasing emotion activated bilateral prefrontal regions. Different activations unique to increasing versus decreasing emotion were observed for positive and negative stimuli: Unique increase-related activations were observed only for positive stimuli, whereas unique decrease-related activations were observed only for negative stimuli. Regulation also modulated activity in the amygdala, a key emotion-processing region. Regulation effects on amygdala activity were larger for positive than for negative stimuli, potentially reflecting a greater malleability of positive emotional reactions. Increasing and decreasing positive and negative emotion can thus increase and decrease subjective reactions and associated amygdala activity in line with regulatory goals, and is associated with different patterns of prefrontal activation as a function of emotional valence and regulatory goal.

Friday, April 27, 2007

ARTICLE UPDATE - The influence of olfactory-induced negative emotion on verbal working memory: Individual differences in neurobehavioral findings

Habel U, Koch K, Pauly K, Kellermann T, Reske M, Backes V, Seiferth NY, Stocker T, Kircher T, Amunts K, Jon Shah N, Schneider F.

Brain Research, in press

The influence of emotion on cognition plays an important role in people's everyday life as well as in psychiatric and neurological disorders. The present study used fMRI to examine the neural correlates of cognitive–emotional interactions and its inter-individual differences. Twenty-one healthy males performed a 0-back/2-back task while negative or neutral emotion was induced by negative/neutral olfactory stimulation. Subjects revealed a differential effect of emotion on cognition; in 9 subjects, negative odor had a deteriorating influence on verbal working memory (“affected group”, AG) while in 12 subjects, performance was not affected in a negative way (“unaffected group”, UAG). Although no brain activation differences emerged during the working memory task, the interaction of working memory and emotion yielded significant differences between the AG and the UAG. The latter showed greater activation in the fronto-parieto-cerebellar working memory (WM) network including the precuneus while the AG demonstrated stronger activation in more “emotional” areas (mainly the temporal and medial frontal cortex) as well as compensatory activations in prefrontal regions known to be essential for the cognitive down-regulation of emotions. Hence, the UAG may have been better able to counteract the detrimental influence of negative stimulation during the 2-back task and to effectively sustain or even increase activation in the task-relevant WM network. Correlation analyses for the whole group supported this interpretation; reduced working memory performance during negative stimulation was accompanied by higher activation in the inferior frontal gyrus whereas less performance impairment was related to higher activation in the precuneus. Results confirm the importance of incorporating individual differences in emotion processing and its interaction with cognitive functions in neuroimaging.

ARTICLE UPDATE - Differential time-dependent effects of emotion on recollective experience and memory for contextual information

Tali Sharot and Andrew P. Yonelinas

Cognition, in press

Emotion has been suggested to slow forgetting via a mechanism that enhances memory consolidation. Here, we investigate whether this time dependent process influences the subjective experience of recollection as well as the ability to retrieve specific contextual details of the study event. To do so we examined recognition for emotional and neutral pictures at two retention intervals and collected remember/know reports and reports about the task that had been performed with the item during encoding. Recollective experience was enhanced for emotional compared to neutral photos after a 24-h delay, but not immediately after encoding. In contrast, memory for the task performed during encoding did not differ between emotional and neutral photos at either time point. The findings indicate that emotion slows the effects of forgetting on the recollective experience associated with studied events, without necessarily slowing the forgetting of specific contextual details of those events.

ARTICLE UPDATE - Affective evaluations of objects are influenced by observed gaze direction and emotional expression

Andrew P. Bayliss, Alexandra Frischen, Mark J. Fenske and Steven P. Tipper

Cognition, in press

Gaze direction signals another person’s focus of interest. Facial expressions convey information about their mental state. Appropriate responses to these signals should reflect their combined influence, yet current evidence suggests that gaze-cueing effects for objects near an observed face are not modulated by its emotional expression. Here, we extend the investigation of perceived gaze direction and emotional expression by considering their combined influence on affective judgments. While traditional response-time measures revealed equal gaze-cueing effects for happy and disgust faces, affective evaluations critically depended on the combined product of gaze and emotion. Target objects looked at with a happy expression were liked more than objects looked at with a disgust expression. Objects not looked at were rated equally for both expressions. Our results demonstrate that facial expression does modulate the way that observers utilize gaze cues: Objects attended by others are evaluated according to the valence of their facial expression.

Tuesday, April 24, 2007

ARTICLE UPDATE - Emotions and False Memories: Valence or Arousal?

Corson, Yves & Verrier, Nadège

Psychological Science, 18, 208-211.

The effects of mood on false memories have not been studied systematically until recently. Some results seem to indicate that negative mood may reduce false recall and thus suggest an influence of emotional valence on false memory. The present research tested the effects of both valence and arousal on recall and recognition and indicates that the effect is actually due to arousal. In fact, whether participants' mood is positive, negative, or neutral, false memories are significantly more frequent under conditions of high arousal than under conditions of low arousal.

Friday, April 20, 2007

ARTICLE UPDATE - Independent Effects of Emotion and Working Memory Load on Visual Activation in the Lateral Occipital Complex

Jan Gläscher, Michael Rose, and Christian Büchel

The Journal of Neuroscience, 27, 4366-4373.

Emotional salience and working memory (WM) load are known to affect object processing in the ventral stream. However, the combined effect, which could be either synergistic or antagonistic, remains unclear. Using functional magnetic resonance imaging and a three-factorial design, we investigated the effects of WM load and emotional salience on object processing in the ventral visual stream. Twenty-three female subjects were shown blocks of task-irrelevant and more or less degraded visual stimuli that varied in emotional valence (negative or neutral) and phase coherence rendering them more or less noisy. Superimposed on these pictures, subjects saw colored squares on which they had to perform a demanding WM task (one-back, two-back). This WM task absorbs attentional resources normally available for the perceptual analysis of visual objects and can therefore be interpreted as a manipulation of attention. We hypothesized that attenuated processing resources in the lateral occipital complex (LOC) for these task-irrelevant pictures under high WM load (Rose et al., 2005) could be regained when they were of negative emotional valence. Our results indicate that both emotional salience and WM load critically depend on a minimum level of phase coherence of the stimuli to affect LOC activation. Furthermore, the influences of emotional salience and WM load do not interact with each other in LOC. Rather, emotional salience exerts a general multiplicative gain effect while preserving the difference in activation between low and high WM load. A connectivity analysis suggests that the emotional modulation might originate in the amygdalo-hippocampal junction.

ARTICLE UPDATE - Affective stimulus properties influence size perception and the Ebbinghaus illusion.

van Ulzen NR, Semin GR, Oudejans RR, Beek PJ.

Psychological Research, in press

In the New Look literature of the 1950s, it has been suggested that size judgments are dependent on the affective content of stimuli. This suggestion, however, has been 'discredited' due to contradictory findings and methodological problems. In the present study, we revisited this forgotten issue in two experiments. The first experiment investigated the influence of affective content on size perception by examining judgments of the size of target circles with and without affectively loaded (i.e., positive, neutral, and negative) pictures. Circles with a picture were estimated to be smaller than circles without a picture, and circles with a negative picture were estimated to be larger than circles with a positive or a neutral picture confirming the suggestion from the 1950s that size perception is influenced by affective content, an effect notably confined to negatively loaded stimuli. In a second experiment, we examined whether affective content influenced the Ebbinghaus illusion. Participants judged the size of a target circle whereby target and flanker circles differed in affective loading. The results replicated the first experiment. Additionally, the Ebbinghaus illusion was shown to be weakest for a negatively loaded target with positively loaded and blank flankers. A plausible explanation for both sets of experimental findings is that negatively loaded stimuli are more attention demanding than positively loaded or neutral stimuli.

ARTICLE UPDATE - Remembering Can Cause Forgetting-but Not in Negative Moods.

Bauml KH, Kuhbandner C.

Psychological Science, 18, 111-115.

Repeated retrieval of a subset of previously observed events can cause forgetting of the nonretrieved events. We examined how affective states experienced during retrieval modulate such retrieval-induced forgetting by inducing positive, negative, and neutral moods in subjects immediately before they attempted to retrieve studied items. On the basis of recent work, we hypothesized that positive moods encourage relational processing, which should increase interference from related events and thus enhance retrieval-induced forgetting. By contrast, negative moods should encourage item-specific processing, which should reduce interference and thus reduce such forgetting. Our results are consistent with these predictions. When subjects were in negative moods, repeated retrieval did not cause forgetting of the nonretrieved material, whereas when subjects were in positive and neutral moods, they showed reliable retrieval-induced forgetting. Our findings suggest that the emotions involved during interrogation of a witness can affect the result of repeated interrogations.

ARTICLE UPDATE - Differential engagement of anterior cingulate cortex subdivisions for cognitive and emotional function.

Mohanty A, Engels AS, Herrington JD, Heller W, Ringo Ho MH, Banich MT, Webb AG, Warren SL, Miller GA.

Psychophysiology, 44, 343-351

Functional differentiation of dorsal (dACC) and rostral (rACC) anterior cingulate cortex for cognitive and emotional function has received considerable indirect support. Using fMRI, parallel tasks, and within-subject analysis, the present study directly tested the proposed specialization of ACC subdivisions. A Task x Region interaction confirmed more dACC activation during color-word distractors and more rACC activation during emotion-word distractors. Activity in ACC subdivisions differentially predicted behavioral performance. Connectivity with prefrontal and limbic regions also supported distinct dACC and rACC roles. Findings provide direct evidence for differential engagement of ACC subdivisions in cognitive and emotional processing and for differential functional connectivity in the implementation of cognitive control and emotion regulation. Results point to an anatomical and functional continuum rather than segregated operations.

ARTICLE UPDATE - Specificity of regional brain activity in anxiety types during emotion processing.

Engels AS, Heller W, Mohanty A, Herrington JD, Banich MT, Webb AG, Miller GA.

Psychophysiology, 44, 352-363.

The present study tested the hypothesis that anxious apprehension involves more left- than right-hemisphere activity and that anxious arousal is associated with the opposite pattern. Behavioral and fMRI responses to threat stimuli in an emotional Stroop task were examined in nonpatient groups reporting anxious apprehension, anxious arousal, or neither. Reaction times were longer for negative than for neutral words. As predicted, brain activation distinguished anxious groups in a left inferior frontal region associated with speech production and in a right-hemisphere inferior temporal area. Addressing a second hypothesis about left-frontal involvement in emotion, distinct left frontal regions were associated with anxious apprehension versus processing of positive information. Results support the proposed distinction between the two types of anxiety and resolve an inconsistency about the role of left-frontal activation in emotion and psychopathology.

Thursday, April 05, 2007

ARTICLE UPDATE - Time course of attentional modulation on automatic emotional processing

Sonia Doallo, Fernando Cadaveira and Socorro Rodríguez Holguín

Neuroscience Letters, in press

In a previous study using event-related potentials (ERPs) [S. Doallo, S. Rodríguez Holguín, F. Cadaveira, Attentional load affects automatic emotional processing: evidence from event-related potentials, Neuroreport 17 (2006) 1797–1801], we reported that differential responses to unattended peripheral affective pictures, as reflected by N1-P2 modulations at posterior regions, are modulated by attentional load at fixation. Here, new analyses of these data were performed to evaluate whether a sustained, broadly distributed, negative shift in the unattended pictures ERP waveforms, which displayed larger amplitudes for emotional stimuli, reflects an additional differential response to the emotional content. Under low-load conditions, unpleasant (versus neutral) pictures elicited greater negativities in the 80–140 ms latency range over frontocentral sites and more centroparietally distributed from 200 to 280 ms. These findings provide further evidence of the time course of emotional processing at unattended locations and its modulation by attentional load.

ARTICLE UPDATE - Modulation of visual processing by attention and emotion: windows on causal interactions between human brain regions

Patrik Vuilleumier and Jon Driver

Philosophical Transactions of the Royal Society B: Biological Sciences, in press

Visual processing is not determined solely by retinal inputs. Attentional modulation can arise when the internal attentional state (current task) of the observer alters visual processing of the same stimuli. This can influence visual cortex, boosting neural responses to an attended stimulus. Emotional modulation can also arise, when affective properties (emotional significance) of stimuli, rather than their strictly visual properties, influence processing. This too can boost responses in visual cortex, as for fear-associated stimuli. Both attentional and emotional modulation of visual processing may reflect distant influences upon visual cortex, exerted by brain structures outside the visual system per se. Hence, these modulations may provide windows onto causal interactions between distant but interconnected brain regions. We review recent evidence, noting both similarities and differences between attentional and emotional modulation. Both can affect visual cortex, but can reflect influences from different regions, such as fronto-parietal circuits versus the amygdala. Recent work on this has developed new approaches for studying causal influences between human brain regions that may be useful in other cognitive domains. The new methods include application of functional magnetic resonance imaging (fMRI) and electroencephalography (EEG) measures in brain-damaged patients to study distant functional impacts of their focal lesions, and use of transcranial magnetic stimulation concurrently with fMRI or EEG in the normal brain. Cognitive neuroscience is now moving beyond considering the putative functions of particular brain regions, as if each operated in isolation, to consider, instead, how distinct brain regions (such as visual cortex, parietal or frontal regions, or amygdala) may mutually influence each other in a causal manner.

ARTICLE UPDATE - Social concepts are represented in the superior anterior temporal cortex.

Roland Zahn, Jorge Moll, Frank Krueger, Edward D. Huey, Griselda Garrido, and Jordan Grafman

PNAS, in press

Social concepts such as "tactless" or "honorable" enable us to describe our own as well as others' social behaviors. The prevailing view is that this abstract social semantic knowledge is mainly subserved by the same medial prefrontal regions that are considered essential for mental state attribution and self-reflection. Nevertheless, neurodegeneration of the anterior temporal cortex typically leads to impairments of social behavior as well as general conceptual knowledge. By using functional MRI, we demonstrate that the anterior temporal lobe represents abstract social semantic knowledge in agreement with this patient evidence. The bilateral superior anterior temporal lobes (Brodmann's area 38) are selectively activated when participants judge the meaning relatedness of social concepts (e.g., honor-brave) as compared with concepts describing general animal functions (e.g., nutritious-useful). Remarkably, only activity in the superior anterior temporal cortex, but not the medial prefrontal cortex, correlates with the richness of detail with which social concepts describe social behavior. Furthermore, this anterior temporal lobe activation is independent of emotional valence, whereas medial prefrontal regions show enhanced activation for positive social concepts. Our results demonstrate that the superior anterior temporal cortex plays a key role in social cognition by providing abstract conceptual knowledge of social behaviors. We further speculate that these abstract conceptual representations can be associated with different contexts of social actions and emotions through integration with frontolimbic circuits to enable flexible evaluations of social behavior.

Friday, March 30, 2007

ARTICLE UPDATE - Repetition and Event-related Potentials: Distinguishing Early and Late Processes in Affective Picture Perception.

Codispoti M, Ferrari V, Bradley MM.

Journal of Cognitive Neuroscience, 19, 577-586

A repetition paradigm was used to assess the nature of affective modulation of early and late components of the event-related potential (ERP) during picture viewing. High-density ERPs were measured while participants passively viewed affective or neutral pictures that were repeated up to 90 times each. Both ERP components were modulated by emotional arousal, with ERPs elicited when viewing pleasant and unpleasant pictures different than when viewing neutral pictures. On the other hand, repetition had different effects on these two components. The early occipitotemporal component (150-300 msec) primarily showed a decrease in amplitude within a block of repetitions that did not differ as a function of picture content. The late centroparietal component (300-600 msec) showed a decrease both between and within blocks of repetitions, with neutral pictures eliciting no late positive potential in the final block of the study. The data suggest that the early ERP primarily reflects obligatory perceptual processing that is facilitated by active short-term memory representations, whereas the late ERP reflects increased resource allocation due to the motivational relevance of affective cues.

PMID: 17381249 [PubMed - in process]

Thursday, March 29, 2007

ARTICLE UPDATE - Feeling the Real World: Limbic Response to Music Depends on Related Content

Eran Eldar, Ori Ganor, Roee Admon, Avraham Bleich and Talma Hendler

Cerebral Cortex, in press

Emotions are often object related—they are about someone or something in the world. It is yet an open question whether emotions and the associated perceptual contents that they refer to are processed by different parts of the brain or whether the brain regions that mediate emotions are also involved in the processing of the associated content they refer to. Using functional magnetic resonance imaging, we showed that simply combining music (rich in emotion but poor in information about the concrete world) with neutral films (poor in emotionality but rich in real-world details) yields increased activity in the amygdala, hippocampus, and lateral prefrontal regions. In contrast, emotional music on its own did not elicit a differential response in these regions. The finding that the amygdala, the heart of the emotional brain, responds increasingly to an emotional stimulus when it is associated with realistic scenes supports a fundamental role for concrete real-world content in emotional processing.

Friday, March 23, 2007

ARTICLE UPDATE - Imitating expressions: emotion-specific neural substrates in facial mimicry

Lee TW, Josephs O, Dolan RJ, Critchley HD.

Social Cognitive Affective Neuroscience, 1, 122-135.

Intentionally adopting a discrete emotional facial expression can modulate the subjective feelings corresponding to that emotion; however, the underlying neural mechanism is poorly understood. We therefore used functional brain imaging (functional magnetic resonance imaging) to examine brain activity during intentional mimicry of emotional and non-emotional facial expressions and relate regional responses to the magnitude of expression-induced facial movement. Eighteen healthy subjects were scanned while imitating video clips depicting three emotional (sad, angry, happy), and two ‘ingestive’ (chewing and licking) facial expressions. Simultaneously, facial movement was monitored from displacement of fiducial markers (highly reflective dots) on each subject’s face. Imitating emotional expressions enhanced activity within right inferior prefrontal cortex. This pattern was absent during passive viewing conditions. Moreover, the magnitude of facial movement during emotion-imitation predicted responses within right insula and motor/premotor cortices. Enhanced activity in ventromedial prefrontal cortex and frontal pole was observed during imitation of anger, in ventromedial prefrontal and rostral anterior cingulate during imitation of sadness and in striatal, amygdala and occipitotemporal during imitation of happiness. Our findings suggest a central role for right inferior frontal gyrus in the intentional imitation of emotional expressions. Further, by entering metrics for facial muscular change into analysis of brain imaging data, we highlight shared and discrete neural substrates supporting affective, action and social consequences of somatomotor emotional expression.

ARTICLE UPDATE - The role of the amygdala in visual awareness.

Duncan S, Barrett LF.

Trends in Cognitive Sciences, in press

Pessoa and colleagues recently reported the novel finding that objective awareness of a negative stimulus is associated with coactivation of the amygdala and fusiform gyrus. Based on the neuroanatomical connections of the amygdala, we suggest that the amygdala is acting to increase neural activity in the fusiform gyrus, thereby increasing the likelihood that visual representations that have affective value reach awareness. The psychological consequence is that a person's momentary affective state might help to select the contents of conscious experience.

ARTICLE UPDATE - The neural mechanism of imagining facial affective expression.

Kim SE, Kim JW, Kim JJ, Jeong BS, Choi EA, Jeong YG, Kim JH, Ku J, Ki SW.

Brain Research, in press

To react appropriately in social relationships, we have a tendency to simulate how others think of us through mental imagery. In particular, simulating other people's facial affective expressions through imagery in social situations enables us to enact vivid affective responses, which may be inducible from other people's affective responses that are predicted as results of our mental imagery of future behaviors. Therefore, this ability is an important cognitive feature of diverse advanced social cognition in humans. We used functional magnetic imaging to examine brain activation during the imagery of emotional facial expressions as compared to neutral facial expressions. Twenty-one right-handed subjects participated in this study. We observed the activation of the amygdala during the imagining of emotional facial affect versus the imagining of neutral facial affects. In addition, we also observed the activation of several areas of the brain, including the dorsolateral prefrontal cortex, ventral premotor cortex, superior temporal sulcus, parahippocampal gyrus, lingual gyrus, and the midbrain. Our results suggest that the areas of the brain known to be involved in the actual perception of affective facial expressions are also implicated in the imagery of affective facial expressions. In particular, given that the processing of information concerning the facial patterning of different emotions and the enactment of behavioral responses, such as autonomic arousal, are central components of the imagery of emotional facial expressions, we postulate the central role of the amygdala in the imagery of emotional facial expressions.

Friday, March 16, 2007

ARTICLE UPDATE - Learning fears by observing others: the neural systems of social fear transmission

Andreas Olsson, Katherine I. Nearing and Elizabeth A. Phelps

Social Cognitive and Affective Neuroscience, in press

Classical fear conditioning has been used as a model paradigm to explain fear learning across species. In this paradigm, the amygdala is known to play a critical role. However, classical fear conditioning requires first-hand experience with an aversive event, which may not be how most fears are acquired in humans. It remains to be determined whether the conditioning model can be extended to indirect forms of learning more common in humans. Here we show that fear acquired indirectly through social observation, with no personal experience of the aversive event, engages similar neural mechanisms as fear conditioning. The amygdala was recruited both when subjects observed someone else being submitted to an aversive event, knowing that the same treatment awaited themselves, and when subjects were subsequently placed in an analogous situation. These findings confirm the central role of the amygdala in the acquisition and expression of observational fear learning, and validate the extension of cross-species models of fear conditioning to learning in a human sociocultural context. Our findings also provides new insights into the relationship between learning from, and empathizing with, fearful others. This study suggests that indirectly attained fears may be as powerful as fears originating from direct experiences.

Tuesday, March 13, 2007

ARTICLE UPDATE - When Danger Lurks in the Background: Attentional Capture by Animal Fear-Relevant Distractors Is Specific and Selectively Enhanced by

Lipp, Ottmar V.; Waters, Allison M.

Emotion, 7, 192-200.

Across 2 experiments, a new experimental procedure was used to investigate attentional capture by animal fear-relevant stimuli. In Experiment 1 (N = 34), unselected participants were slower to detect a neutral target animal in the presence of a spider than a cockroach distractor and in the presence of a snake than a large lizard distractor. This result confirms that phylogenetically fear-relevant animals capture attention specifically and to a larger extent than do non-fear-relevant animals. In Experiment 2 (N = 86), detection of a neutral target animal was slowed more in the presence of a feared fear-relevant distractor (e.g., a snake for snake-fearful participants) than in presence of a not-feared fear-relevant distractor (e.g., a spider for snake-fearful participants). These results indicate preferential attentional capture that is specific to phylogenetically fear-relevant stimuli and is selectively enhanced in individuals who fear these animals. (PsycINFO Database Record (c) 2007 APA, all rights reserved)

ARTICLE UPDATE - Distinguishing Between Automaticity and Attention in the Processing of Emotionally Significant Stimuli.

Okon-Singer, Hadas; Tzelgov, Joseph; Henik, Avishai

Emotion, 7, 147-157.

There is contradicting evidence as to whether irrelevant but significant emotional stimuli can be processed outside the focus of attention. In the current study, participants were asked to ignore emotional and neutral pictures while performing a competing task. In Experiment 1, orienting of attention to distracting pictures was manipulated via a peripheral cue. In Experiment 2, attentional load was varied, either leaving spare attention to process the distracting pictures or, alternatively, depleting attentional resources. Although all pictures were task irrelevant, negative pictures were found to interfere more with performance in comparison to neutral pictures. This finding suggests that processing of negative stimuli is automatic in the sense that it does not require execution of conscious monitoring. However, interference occurred only when sufficient attention was available for picture processing. Hence, processing of negative pictures was dependent on sufficient attentional resources. This suggests that processing of emotionally significant stimuli is automatic yet requires attention. (PsycINFO Database Record (c) 2007 APA, all rights reserved)

ARTICLE UPDATE - The Role of Attention and Relatedness in Emotionally Enhanced Memory.

Talmi, Deborah; Schimmack, Ulrich; Paterson, Theone; Moscovitch, Morris

Emotion, 7, 89-102.

Examining the positive and negative pictures separately revealed that emotionally enhanced memory (EEM) for positive pictures was mediated by attention, with no significant influence of emotional arousal, whereas the reverse was true of negative pictures. Consistent with this finding, in Experiment 2 EEM for negative pictures was found even when task emphasis was manipulated so that equivalent attention was allocated to negative and neutral pictures. The results show that attention and semantic relatedness contribute to EEM, with the extent varying with emotional valence. Negative emotion can influence memory independently of these 2 factors. (PsycINFO Database Record (c) 2007 APA, all rights reserved)

ARTICLE UPDATE - Inhibition of Return to Social Signals of Fear.

Stoyanova, Raliza S.; Pratt, Jay; Anderson, Adam K.

Emotion, 7, 49-56.

The present study examined whether inhibition of return (IOR) is modulated by the fear relevance of the cue. Experiment 1 found similar magnitude of IOR was produced by neutral and fear faces and luminance matched cues. To allow a more sensitive measure of endogenously directed attention, Experiment 2 removed a central reorienting cue and more precisely measured the time course of IOR. At stimulus onset asynchronies (SOAs) of 500, 1,000 and 1,500 ms, fear face and luminance matched cues resulted in similar IOR. These findings suggest that IOR is triggered by event onsets and disregards event value. Views of IOR as an adaptive "foraging facilitator," whereby attention is guided to promote optimal sampling of important environmental events, are discussed. (PsycINFO Database Record (c) 2007 APA, all rights reserved)

Friday, March 09, 2007

ARTICLE UPDATE - Reward expectancy-related prefrontal neuronal activities: are they neural substrates of "affective" working memory?

Watanabe M, Hikosaka K, Sakagami M, Shirakawa S.

Cortex, 43, 53-64

Primate prefrontal delay neurons are involved in retaining task-relevant cognitive information in working memory (WM). Recent studies have also revealed primate prefrontal delay neurons that are related to reward/omission-of-reward expectancy. Such reward-related delay activities might constitute "affective WM" (Davidson, 2002). "Affective" and "cognitive" WM are both concerned with representing not what is currently being presented, but rather what was presented previously or might be presented in the future. However, according to the original and widely accepted definition, WM is the "temporary storage and manipulation of information for complex cognitive tasks". Reward/omission-of-reward expectancy-related neuronal activity is neither prerequisite nor essential for accurate task performance; thus, such activity is not considered to comprise the neural substrates of WM. Also, "affective WM" might not be an appropriate usage of the term "WM". We propose that WM- and reward/omission-of-reward expectancy-related neuronal activity are concerned with representing which response should be performed in order to attain a goal (reward) and the goal of the response, respectively. We further suggest that the prefrontal cortex (PFC) plays a crucial role in the integration of cognitive (for example, WM-related) and motivational (for example, reward expectancy-related) operations for goal-directed behaviour. The PFC could then send this integrated information to other brain areas to control the behaviour.

ARTICLE UPDATE - Affective priming of nonaffective semantic categorization responses.

Spruyt A, De Houwer J, Hermans D, Eelen P.

Experimental Psychology, 54, 44-53

Recent studies have shown that robust affective priming effects can be obtained when participants are required to categorize the targets on the basis of their valence, but not when participants are asked to categorize the targets on the basis of nonaffective features. On the basis of this pattern of results, it has been argued that affective priming is due to processes that operate at a response selection stage rather than to processes that operate at an encoding stage. We demonstrate (a) that affective priming of nonaffective semantic categorization responses can be obtained when participants assign attention to the affective stimulus dimension, and (b) that affective priming in the standard evaluative categorization task is strongly reduced when participants assign attention to nonaffective stimulus features. On the basis of these findings, we argue (a) that processes operating at an encoding stage do contribute to the affective priming effect, and (b) that automatic affective stimulus processing is reduced when participants selectively attend to nonaffective stimulus features.

ARTICLE UPDATE - Seeing fearful body language overcomes attentional deficits in patients with neglect.Tamietto M, Geminiani G, Genero R, de Gelder B.

Tamietto M, Geminiani G, Genero R, de Gelder B.

Journal of Cognitive Neuroscience, 19, 445-454

Survival depends to some extent on the ability to detect salient signals and prepare an appropriate response even when attention is engaged elsewhere. Fearful body language is a salient signal of imminent danger, easily observable from a distance and indicating to the observer which adaptive action to prepare for. Here we investigated for the first time whether fearful body language modulates the spatial distribution of attention and enhances visual awareness in neurological patients with severe attentional disorders. Patients with visual extinction and hemispatial neglect following right parietal injury have a rightward attentional bias accompanied by loss of awareness for contralesional left stimuli, especially when competing stimuli appear to the right. Three such patients were tested with pictures of fearful, happy, and neutral bodily expressions briefly presented either unilaterally in the left or right visual field, or to both fields simultaneously. On bilateral trials, unattended and task-irrelevant fearful bodily expressions modulated attentional selection and visual awareness. Fearful bodily expressions presented in the contralesional unattended visual field simultaneously with neutral bodies in the ipsilesional field were detected more often than left-side neutral or happy bodies. This demonstrates that despite pathological inattention and parietal damage, emotion and action-related information in fearful body language may be extracted automatically, biasing attentional selection and visual awareness. Our findings open new perspectives on the role of bodily expressions in attentional selection and suggest that a neural network in intact fronto-limbic and visual areas may still mediate reorienting of attention and preparation for action upon perceiving fear in others.

ARTICLE UPDATE - Role of anticipated reward in cognitive behavioral control

Masataka Watanabe

Current Opinion in Neurobiology, in press

The lateral prefrontal cortex (LPFC), which is important for higher cognitive activity, is also concerned with motivational operations; this is exemplified by its activity in relation to expectancy of rewards. In the LPFC, motivational information is integrated with cognitive information, as demonstrated by the enhancement of working-memory-related activity by reward expectancy. Such activity would be expected to induce changes in attention and, subsequently, to modify behavioral performance. Recently, the effects of motivation and emotion on neural activities have been examined in several areas of the brain in relation to cognitive-task performance. Of these areas, the LPFC seems to have the most important role in adaptive goal-directed behavior, by sending top-down attention-control signals to other areas of the brain.

ARTICLE UPDATE - Contrasting roles for cingulate and orbitofrontal cortex in decisions and social behaviour.

.F.S. Rushworth, T.E.J. Behrens, P.H. Rudebeck and M.E. Walton

Trends in Cognitive Sciences, in press

There is general acknowledgement that both the anterior cingulate and orbitofrontal cortex are implicated in reinforcement-guided decision making, and emotion and social behaviour. Despite the interest that these areas generate in both the cognitive neuroscience laboratory and the psychiatric clinic, ideas about the distinctive contributions made by each have only recently begun to emerge. This reflects an increasing understanding of the component processes that underlie reinforcement-guided decision making, such as the representation of reinforcement expectations, the exploration, updating and representation of action values, and the appreciation that choices are guided not just by the prospect of reward but also by the costs that action entails. Evidence is emerging to suggest that the anterior cingulate and orbitofrontal cortex make distinct contributions to each of these aspects of decision making.

Friday, March 02, 2007

ARTICLE UPDATE - As Time Goes By: Temporal Constraints on Emotional Activation of Inferior Medial Prefrontal Cortex

Jacob Geday, Ron Kupers and Albert Gjedde

Cerebral Cortex, in press

To investigate the influence of stimulus duration on emotional processing, we measured changes of regional cerebral blood flow (rCBF) in 14 healthy subjects who viewed neutral or emotional images presented for 3 or 6 s. Presentation for 3 s reproduced the previous result of higher rCBF in inferior medial prefrontal cortex (IMPC) during neutral than emotional stimulation. Six-second presentation reverted this relationship, with activity in IMPC being higher during emotional stimulation. Prolonged stimulus presentation attenuated the rise of rCBF associated with emotions in left parietal cortex and cerebellar hemisphere. We speculate that the different rCBF during neutral and emotional stimulation for 6 s is a consequence of attention divided between the emotional stimuli and their associations. Thus, prefrontal activity rises when a cognitive task accompanies emotional stimulation because several cognitive processes compete for attention. The IMPC may serve the mechanism of attention underlying the concept of a default mode of brain function, selecting among competitive inputs from multiple brain regions rather than just processing emotions. The results emphasize the importance of implicit cognitive processing during emotional activation, however, unintended.

ARTICLE UPDATE - Event-related potential study of attention capture by affective sounds.

Thierry G, Roberts MV.

NeuroReport, 18, 245-248

Affective pictures trigger attentional responses in humans but very little is known about the processing of affective environmental sounds. Here, we used an oddball event-related potential paradigm to determine the saliency of unpleasant sounds presented among affectively neutral sounds. Participants performed a one-back task while listening to pseudo-randomized sound sequences comprising 70% neutral sounds, 15% unpleasant sounds of matched peak intensity, and 15% louder neutral sounds. Louder neutral sounds elicited a larger N1 component and a significant P3a variation with a central distribution. Unpleasant sounds did not affect early components but elicited a significant frontocentral P3a modulation. We conclude that affective environmental sounds spontaneously capture human attention but fail to modulate early perceptual processing when sound peak intensity is controlled.

ARTICLE UPDATE - Enhancement of activity of the primary visual cortex during processing of emotional stimuli as measured with event-related functional

Martin J. Herrmann, Theresa Huter, Michael Plichta, Ann-Christine Ehlis, Georg W. Alpers, Andreas Mühlberger, Andreas J. Fallgatter

Human Brain Mapping, in press

In this study we investigated whether event-related near-infrared spectroscopy (NIRS) is suitable to measure changes in brain activation of the occipital cortex modulated by the emotional content of the visual stimuli. As we found in a previous pilot study that only positive but not negative stimuli differ from neutral stimuli (with respect to oxygenated haemoglobin), we now measured the event-related EEG potentials and NIRS simultaneously during the same session. Thereby, we could evaluate whether the subjects (n = 16) processed the positive as well as the negative emotional stimuli in a similar way. During the task, the subjects passively viewed positive, negative, and neutral emotional pictures (40 presentations were shown in each category, and pictures were taken from the International Affective Picture System, IAPS). The stimuli were presented for 3 s in a randomized order (with a mean of 3 s interstimulus interval). During the task, we measured the event-related EEG potentials over the electrode positions O1, Oz, O2, and Pz and the changes of oxygenated and deoxygenated haemoglobin by multichannel NIRS over the occipital cortex. The EEG results clearly show an increased early posterior negativity over the occipital cortex for both positive as well as negative stimuli compared to neutral. The results for the NIRS measurement were less clear. Although positive as well as negative stimuli lead to significantly higher decrease in deoxygenated haemoglobin than neutral stimuli, this was not found for the oxygenated haemoglobin.

ARTICLE UPDATE - Reduced specificity of autobiographical memory and depression: the role of executive control.

Dalgleish T, Golden AM, Barrett LF, Au Yeung C, Murphy V, Tchanturia K, Williams JM, Perkins N, Barnard PJ, Elward R, Watkins E.

Journal of Experimental Psychology: General, 136, 23-42.

It has been widely established that depressed mood states and clinical depression, as well as a range of other psychiatric disorders, are associated with a relative difficulty in accessing specific autobiographical information in response to emotion-related cue words on an Autobiographical Memory Test (AMT; J. M. G. Williams & K. Broadbent, 1986). In 8 studies the authors examined the extent to which this relationship is a function of impaired executive control associated with these mood states and clinical disorders. Studies 1-4 demonstrated that performance on the AMT is associated with performance on measures of executive control, independent of depressed mood. Furthermore, Study 1 showed that executive control (as measured by verbal fluency) mediated the relationship between both depressed mood and a clinical diagnosis of eating disorder and AMT performance. Using a stratified sample in Study 5, the authors confirmed the positive association between depressed mood and impaired performance on the AMT. Studies 6-8 involved experimental manipulations of the parameters of the AMT designed to further indicate that reduced executive control is to a significant extent driving the relationship between depressed mood and AMT performance. The potential role of executive control in accounting for other aspects of the AMT literature is discussed.

ARTICLE UPDATE - Emotion and consciousness

Tsuchiya N, Adolphs R.

Trends in Cognitive Sciences, in press

Consciousness and emotion feature prominently in our personal lives, yet remain enigmatic. Recent advances prompt further distinctions that should provide more experimental traction: we argue that emotion consists of an emotion state (functional aspects, including emotional response) as well as feelings (the conscious experience of the emotion), and that consciousness consists of level (e.g. coma, vegetative state and wakefulness) and content (what it is we are conscious of). Not only is consciousness important to aspects of emotion but structures that are important for emotion, such as brainstem nuclei and midline cortices, overlap with structures that regulate the level of consciousness. The intersection of consciousness and emotion is ripe for experimental investigation, and we outline possible examples for future studies.

ARTICLE UPDATE - Emotion recognition from dynamic emotional displays following anterior cingulotomy and anterior capsulotomy for chronic depression

Nathan Ridout, Ronan E. O’Carroll, Barbara Dritschel, David Christmasd, Muftah Eljamel and Keith Matthews

Neuropsychologia, in press

Four patients that had received an anterior cingulotomy (ACING) and five patients that had received both an ACING and an anterior capsulotomy (ACAPS) as an intervention for chronic, treatment refractory depression were presented with a series of dynamic emotional stimuli and invited to identify the emotion portrayed. Their performance was compared with that of a group of non-surgically treated patients with major depression (n = 17) and with a group of matched, never-depressed controls (n = 22). At the time of testing, four of the nine neurosurgery patients had recovered from their depressive episode, whereas five remained depressed. Analysis of emotion recognition accuracy revealed no significant differences between depressed and non-depressed neurosurgically treated patients. Similarly, no significant differences were observed between the patients treated with ACING alone and those treated with both ACING and ACAPS. Comparison of the emotion recognition accuracy of the neurosurgically treated patients and the depressed and healthy control groups revealed that the surgically treated patients exhibited a general impairment in their recognition accuracy compared to healthy controls. Regression analysis revealed that participants’ emotion recognition accuracy was predicted by the number of errors they made on the Stroop colour-naming task. It is plausible that the observed deficit in emotion recognition accuracy was a consequence of impaired attentional control, which may have been a result of the surgical lesions to the anterior cingulate cortex.

Friday, February 23, 2007

ARTICLE UPDATE - Affective Interactions Using Virtual Reality: The Link between Presence and Emotions.

Riva G, Mantovani F, Capideville CS, Preziosa A, Morganti F, Villani D, Gaggioli A, Rotella C, Alcaniz M.

Cyberpsychology & Behavior, 10, 45-56

Many studies showed the ability of movies and imagery techniques to elicit emotions. Nevertheless, it is less clear how to manipulate the content of interactive media to induce specific emotional responses. In particular, this is true for the emerging medium virtual reality (VR), whose main feature is the ability to induce a feeling of "presence" in the computer-generated world experienced by the user. The main goal of this study was to analyze the possible use of VR as an affective medium. Within this general goal, the study also analyzed the relationship between presence and emotions. The results confirmed the efficacy of VR as affective medium: the interaction with "anxious" and "relaxing" virtual environments produced anxiety and relaxation. The data also showed a circular interaction between presence and emotions: on one side, the feeling of presence was greater in the "emotional" environments; on the other side, the emotional state was influenced by the level of presence. The significance of these results for the assessment of affective interaction is discussed.

Friday, February 16, 2007

ARTICLE UPDATE - A functional MRI study of happy and sad affective states induced by classical musi

Martina T. Mitterschiffthaler , Cynthia H.Y. Fu, Jeffrey A. Dalton , Christopher M. Andrew , Steven C.R. Williams

Human Brain Mapping, in press

The present study investigated the functional neuroanatomy of transient mood changes in response to Western classical music. In a pilot experiment, 53 healthy volunteers (mean age: 32.0; SD = 9.6) evaluated their emotional responses to 60 classical musical pieces using a visual analogue scale (VAS) ranging from 0 (sad) through 50 (neutral) to 100 (happy). Twenty pieces were found to accurately induce the intended emotional states with good reliability, consisting of 5 happy, 5 sad, and 10 emotionally unevocative, neutral musical pieces. In a subsequent functional magnetic resonance imaging (fMRI) study, the blood oxygenation level dependent (BOLD) signal contrast was measured in response to the mood state induced by each musical stimulus in a separate group of 16 healthy participants (mean age: 29.5; SD = 5.5). Mood state ratings during scanning were made by a VAS, which confirmed the emotional valence of the selected stimuli. Increased BOLD signal contrast during presentation of happy music was found in the ventral and dorsal striatum, anterior cingulate, parahippocampal gyrus, and auditory association areas. With sad music, increased BOLD signal responses were noted in the hippocampus/amygdala and auditory association areas. Presentation of neutral music was associated with increased BOLD signal responses in the insula and auditory association areas. Our findings suggest that an emotion processing network in response to music integrates the ventral and dorsal striatum, areas involved in reward experience and movement; the anterior cingulate, which is important for targeting attention; and medial temporal areas, traditionally found in the appraisal and processing of emotions. Hum Brain Mapp 2007. © 2006 Wiley-Liss, Inc.

Friday, February 09, 2007

ARTICLE UPDATE - Affective visual event-related potentials: Arousal, repetition, and time-on-task.

Jonas K. Olofsson and John Polich

Biological Psychology, in press

Affective stimulus pictures that differed in valence (unpleasant, neutral, and pleasant) were repeated as targets in an oddball task to elicit event-related potentials (ERPs) in young female adults. Each picture target was repeated consecutively four times, with picture order counterbalanced and time-on-task influences assessed across subjects. Response time decreased from the first to second stimulus presentation and remained stable. Stimulus repetition was associated with voltage increases for N1, P2, N2, and P3, from initial to subsequent presentations. Arousal effects did not interact with stimulus repetition at any latency range. Time-on-task was associated with decreased voltages for the N2 and P3 potentials but was unaffected by stimulus valence. The findings suggest affective arousal, stimulus repetition, and time-on-task independently modulate ERP outcomes at overlapping time ranges. Theoretical implications are discussed.

Friday, February 02, 2007

ARTICLE UPDATE - Selective Visual Attention to Emotion

Harald T. Schupp, Jessica Stockburger, Maurizio Codispoti, Markus Junghöfer, Almut I. Weike, and Alfons O. Hamm

The Journal of Neuroscience, 27, 1082-1089

Visual attention can be voluntarily directed toward stimuli and is attracted by stimuli that are emotionally significant. The present study explored the case when both processes coincide and attention is directed to emotional stimuli. Participants viewed a rapid and continuous stream of high-arousing erotica and mutilation stimuli as well as low-arousing control images. Each of the three stimulus categories served in separate runs as target or nontarget category. Event-related brain potential measures revealed that the interaction of attention and emotion varied for specific processing stages. The effects of attention and emotional significance operated additively during perceptual encoding indexed by negative-going potentials over posterior regions (~200–350 ms after stimulus onset). In contrast, thought to reflect the process of stimulus evaluation, P3 target effects (~400–600 ms after stimulus onset) were markedly augmented when erotica and mutilation compared with control stimuli were the focus of attention. Thus, emotion potentiated attention effects specifically during later stages of processing. These findings suggest to specify the interaction of attention and emotion in distinct processing stages.

Friday, January 26, 2007

ARTICLE UPDATE - Modulation of emotion by cognition and cognition by emotion

K.S. Blaira, B.W. Smithb, D.G.V. Mitchella, J. Mortonc, M. Vythilingama, L. Pessoad, D. Fridberga, A. Zametkina, D. Sturmane, E.E. Nelsona, W.C. Drevetsa, D.S. Pinea, A. Martine and R.J.R. Blair

NeuroImage, in press

In this study, we examined the impact of goal-directed processing on the response to emotional pictures and the impact of emotional pictures on goal-directed processing. Subjects (N = 22) viewed neutral or emotional pictures in the presence or absence of a demanding cognitive task. Goal-directed processing disrupted the BOLD response to emotional pictures. In particular, the BOLD response within bilateral amygdala and inferior frontal gyrus decreased during concurrent task performance. Moreover, the presence of both positive and negative distractors disrupted task performance, with reaction times increasing for emotional relative to neutral distractors. Moreover, in line with the suggestion of the importance of lateral frontal regions in emotional regulation [Ochsner, K. N., Ray, R. D., Cooper, J. C., Robertson, E. R., Chopra, S., Gabrieli, J. D., et al. (2004). For better or for worse: neural systems supporting the cognitive down-and up-regulation of negative emotion. NeuroImage, 23(2), 483–499], connectivity analysis revealed positive connectivity between lateral superior frontal cortex and regions of middle frontal cortex previously implicated in emotional suppression [Beauregard, M., Levesque, J., and Bourgouin, P. (2001). Neural correlates of conscious self-regulation of emotion. J. Neurosci., 21 (18), RC165.; Levesque, J., Eugene, F., Joanette, Y., Paquette, V., Mensour, B., Beaudoin, G., et al. (2003). Neural circuitry underlying voluntary suppression of sadness. Biol. Psychiatry, 53 (6), 502–510.; Ohira, H., Nomura, M., Ichikawa, N., Isowa, T., Iidaka, T., Sato, A., et al. (2006). Association of neural and physiological responses during voluntary emotion suppression. NeuroImage, 29 (3), 721–733] and negative connectivity with bilateral amygdala. These data suggest that processes involved in emotional regulation are recruited during task performance in the context of emotional distractors.

Friday, January 12, 2007

ARTICLE UPDATE - Aware and (Dis)Liking: Item-Based Analyses Reveal That Valence Acquisition via Evaluative Conditioning Emerges Only When There Is Con

Pleyers G, Corneille O, Luminet O, Yzerbyt V.

Journal of Experimental Psychology: Learning, Memory & Cognition, 33, 130-144.

Evaluative conditioning (EC) refers to changes in the liking of an affectively neutral stimulus (the conditioned stimulus, or CS) following the pairing of that stimulus with another stimulus of affective value (the unconditioned stimulus, or US). In 3 experiments, the authors assessed contingency awareness, that is, awareness of the CS-US associations, by relying on participants' responses to individual items rather than using a global method of assessment. They found that EC emerged on contingency aware CSs only. Of note, whether the CSs were evaluated explicitly (Experiments 1 and 2) or implicitly (Experiment 3) did not make a difference. This pattern supports the idea that awareness of the CS-US associations may be required for valence acquisition via EC.

ARTICLE UPDATE - Amygdala reactivity predicts automatic negative evaluations for facial emotions.

Dannlowski U, Ohrmann P, Bauer J, Kugel H, Arolt V, Heindel W, Suslow T.

Psychiatry Research, in press

The amygdala is a key structure in a limbic circuit involved in the rapid and unconscious processing of facial emotions. In the present study, the role of the amygdala in automatic, involuntary appraisal processes, which are believed to be a crucial component of emotion processing, was investigated in 23 healthy subjects. Amygdala activity was recorded in response to masked displays of angry, sad, and happy facial expressions using functional magnetic resonance imaging (fMRI). In a subsequent experiment, the subjects performed a masked affective priming task that characterizes automatic emotion processing by investigating the biasing effect of subliminally presented emotional faces on evaluative ratings to subsequently presented neutral stimuli. In the affective priming task, significant valence-congruent evaluation manipulation was observed. Subjects rated neutral targets more positively if they were primed by happy faces. Significant correlations were found between amygdala responses to masked negative facial expressions and negative evaluation shifts elicited by the corresponding emotion quality in the affective priming task. Spontaneous amygdala reactivity to facial emotions appears to be a determinant of automatic negative evaluative response tendencies. This finding might shed some light on how amygdala hyperresponsivity contributes to negative cognitive biases commonly observed in affective disorders.

ARTICLE UPDATE - Categorical perception of anger and disgust facial expression is affected by non-clinical social anxiety: An ERP study.

Rossignol M, Anselme C, Vermeulen N, Philippot P, Campanella S.

Brain Research, in press

Anxiety has been associated with a bias for interpreting threatening information. Faces expressing anger seem to be more easily detected by socially anxious individuals than by non-anxious individuals. Similarly, disgust on a face may also reflect a negative social judgment. We tested the hypothesis that individuals displaying non-clinical social anxiety would be as sensitive to disgust as to anger interpretation by comparing individuals scoring high or low on the fear of social evaluation scale (FNE, Watson and Friend, 1969). Event-related potentials (ERP) were recorded in response to repetitions of a particular facial expression (e.g. anger) and in response to two deviating (rare) stimuli obtained by a morphing procedure, where one depicted the same emotion as the frequent stimulus, while the other depicted a different facial expression (e.g. disgust). The classic effect of categorical perception was reproduced: at a behavioral level, people detected more easily rare faces depicting a different emotion than faces depicting the same emotion. ERP results suggest that deviant faces depicting a different emotion evoked an earlier attentional N2b/P3a wave complex, together with an earlier and enhanced P3b. More interestingly, participants with non-clinical social anxiety manifested a reduced N2b wave when they had to detect a change in intensity of anger presentation. However, these individuals did not show facilitation to disengage from disgust when they have to detect angry faces, which was displayed by control participants. Implications and suggestions for further research about the role played by anger and disgust in psychopathology are outlined.

Monday, January 08, 2007

ARTICLE UPDATE - Affective biasing of choices in gambling task decision making

Hinson, John M.; Whitney, Paul; Holben, Heather; Wirick, Aaron K.

Cognitive, Affective, & Behavioral Neuroscience, 6, 190-200

The proponents of the somatic marker hypothesis presume that rational decision making is guided by emotional reactions that are developed from prior experience. Supporting evidence for the hypothesis comes almost exclusively from the short-term affective reactions that are learned during the course of a hypothetical decision-making task—the gambling task (Gt). We examined GT performance and affective reactions to choices when those choices were biased by words that had preexisting affective value. In one experiment, affectively valued words directly signaled good and bad choices. A congruent relation between affective value of word and choice outcome improved GT performance, whereas an incongruent relation greatly interfered with performance. In another experiment, affectively valued words were maintained as a working memory (WM) load between GT choices. A WM load with affectively positive words somewhat improved GT performance, whereas affectively negative words interfered with performance. Somatic markers—indicated by differential anticipatory skin conductance response (scr) amplitude for good and bad choices—appeared at a point in the GT session when choice performance was superior. However, differential scr developed during the session after good choice performance was already established. These results indicate that preexisting affective biases can influence GT decision making. In addition, the somatic markers that are regular accompaniments of GT decision making appeared to be temporally lagging indicators of choice performance.

ARTICLE UPDATE - Positive affect increases the breadth of attentional selection

G. Rowe, J. B. Hirsh, and A. K. Anderson

PNAS, 104, 383-388

The present study examined the thesis that positive affect may serve to broaden the scope of attentional filters, reducing their selectivity. The effect of positive mood states was measured in two different cognitive domains: semantic search (remote associates task) and visual selective attention (Eriksen flanker task). In the conceptual domain, positive affect enhanced access to remote associates, suggesting an increase in the scope of semantic access. In the visuospatial domain, positive affect impaired visual selective attention by increasing processing of spatially adjacent flanking distractors, suggesting an increase in the scope of visuospatial attention. During positive states, individual differences in enhanced semantic access were correlated with the degree of impaired visual selective attention. These findings demonstrate that positive states, by loosening the reins on inhibitory control, result in a fundamental change in the breadth of attentional allocation to both external visual and internal conceptual space.

Friday, December 15, 2006

ARTICLE UPDATE - Attentional load affects automatic emotional processing: evidence from event-related potentials.

Doallo S, Holguin SR, Cadaveira F.

Neuroreport, 17, 1797-1801

One open question on the relation between attention and emotion concerns the automatic processing of emotional visual stimuli outside the focus of attention. This study examined to what extent the emotional processing at unattended locations is modulated by the processing load at attended locations. Event-related potentials were measured to task-irrelevant unpleasant and neutral pictures briefly presented at peripheral locations while participants performed a visual central task varying in load (low and high load). Unpleasant pictures elicited larger amplitudes of N1-P2 at parietoccipital and occipital sites than that of neutral pictures. This effect was only significant in the low-load condition. Data suggest that brain responses to affective value of task-irrelevant peripheral pictures are modulated by attentional load at fixation.

ARTICLE UPDATE - Sequence of information processing for emotions based on the anatomic dialogue between prefrontal cortex and amygdala

H.T. Ghashghaei, 1, C.C. Hilgetag, d and H. Barbas

NeuroImage, in press

The prefrontal cortex and the amygdala have synergistic roles in regulating purposive behavior, effected through bidirectional pathways. Here we investigated the largely unknown extent and laminar relationship of prefrontal input–output zones linked with the amygdala using neural tracers injected in the amygdala in rhesus monkeys. Prefrontal areas varied vastly in their connections with the amygdala, with the densest connections found in posterior orbitofrontal and posterior medial cortices, and the sparsest in anterior lateral prefrontal areas, especially area 10. Prefrontal projection neurons directed to the amygdala originated in layer 5, but significant numbers were also found in layers 2 and 3 in posterior medial and orbitofrontal cortices. Amygdalar axonal terminations in prefrontal cortex were most frequently distributed in bilaminar bands in the superficial and deep layers, by columns spanning the entire cortical depth, and less frequently as small patches centered in the superficial or deep layers. Heavy terminations in layers 1–2 overlapped with calbindin-positive inhibitory neurons. A comparison of the relationship of input to output projections revealed that among the most heavily connected cortices, cingulate areas 25 and 24 issued comparatively more projections to the amygdala than they received, whereas caudal orbitofrontal areas were more receivers than senders. Further, there was a significant relationship between the proportion of ‘feedforward’ cortical projections from layers 2–3 to ‘feedback’ terminations innervating the superficial layers of prefrontal cortices. These findings indicate that the connections between prefrontal cortices and the amygdala follow similar patterns as corticocortical connections, and by analogy suggest pathways underlying the sequence of information processing for emotions.

ARTICLE UPDATE - The impact of processing load on emotion.

D.G.V. Mitchell, M. Nakic, D. Fridberg, N. Kamel, D.S. Pine and R.J.R. Blair

NeuroImage, in press

This event-related fMRI study examined the impact of processing load on the BOLD response to emotional expressions. Participants were presented with composite stimuli consisting of neutral and fearful faces upon which semi-transparent words were superimposed. This manipulation held stimulus-driven features constant across multiple levels of processing load. Participants made either (1) gender discriminations based on the face; (2) case judgments based on the words; or (3) syllable number judgments based on the words. A significant main effect for processing load was revealed in prefrontal cortex, parietal cortex, visual processing areas, and amygdala. Critically, enhanced activity in the amygdala and medial prefrontal cortex seen during gender discriminations was significantly reduced during the linguistic task conditions. A connectivity analysis conducted to investigate theories of cognitive modulation of emotion showed that activity in dorsolateral prefrontal cortex was inversely related to activity in the ventromedial prefrontal cortex. Together, the data suggest that the processing of task-irrelevant emotional information, like neutral information, is subject to the effects of processing load and is under top-down control.

Monday, December 04, 2006

ARTICLE UPDATE - Emotional memories are not all created equal: Evidence for selective memory enhancement

Adam K. Anderson, Yuki Yamaguchi, Wojtek Grabski, and Dominika Lacka

LEARNING & MEMORY, 13, 711-718

Human brain imaging studies have shown that greater amygdala activation to emotional relative to neutral events leads to enhanced episodic memory. Other studies have shown that fearful faces also elicit greater amygdala activation relative to neutral faces. To the extent that amygdala recruitment is sufficient to enhance recollection, these separate lines of evidence predict that recognition memory should be greater for fearful relative to neutral faces. Experiment 1 demonstrated enhanced memory for emotionally negative relative to neutral scenes; however, fearful faces were not subject to enhanced recognition across a variety of delays (15 min to 2 wk). Experiment 2 demonstrated that enhanced delayed recognition for emotional scenes was associated with increased sympathetic autonomic arousal, indexed by the galvanic skin response, relative to fearful faces. These results suggest that while amygdala activation may be necessary, it alone is insufficient to enhance episodic memory formation. It is proposed that a sufficient level of systemic arousal is required to alter memory consolidation resulting in enhanced recollection of emotional events.

Friday, December 01, 2006

ARTICLE UPDATE - Regulation of emotional responses elicited by threat-related stimuli.

Eippert F, Veit R, Weiskopf N, Erb M, Birbaumer N, Anders S.

Human Brain Mapping, in press

The capacity to voluntarily regulate emotions is critical for mental health, especially when coping with aversive events. Several neuroimaging studies of emotion regulation found the amygdala to be a target for downregulation and prefrontal regions to be associated with downregulation. To characterize the role of prefrontal regions in bidirectional emotion regulation and to investigate regulatory influences on amygdala activity and peripheral physiological measures, a functional magnetic resonance imaging (fMRI) study with simultaneous recording of self-report, startle eyeblink, and skin conductance responses was carried out. Subjects viewed threat-related pictures and were asked to up- and downregulate their emotional responses using reappraisal strategies. While startle eyeblink responses (in successful regulators) and skin conductance responses were amplified during upregulation, but showed no consistent effect during downregulation, amygdala activity was increased and decreased according to the regulation instructions. Trial-by-trial ratings of regulation success correlated positively with activity in amygdala during upregulation and orbitofrontal cortex during downregulation. Downregulation was characterized by left-hemispheric activation peaks in anterior cingulate cortex, dorsolateral prefrontal cortex, and orbitofrontal cortex and upregulation was characterized by a pattern of prefrontal activation not restricted to the left hemisphere. Further analyses showed significant overlap of prefrontal activation across both regulation conditions, possibly reflecting cognitive processes underlying both up- and downregulation, but also showed distinct activations in each condition. The present study demonstrates that amygdala responses to threat-related stimuli can be controlled through the use of cognitive strategies depending on recruitment of prefrontal areas, thereby changing the subject's affective state.

Wednesday, November 29, 2006

ARTICLE UPDATE - An electrophysiological study on the interaction between emotional content and spatial frequency of visual stimuli

Luis Carretié, José A. Hinojosa, Sara López-Martín and Manuel Tapia

Neuropsychologia, in press

Previous studies suggest that the magnocellular pathway, a visual processing system that rapidly provides low spatial frequency information to fast-responding structures such as the amygdala, is more involved in the processing of emotional facial expressions than the parvocellular pathway (which conveys all spatial frequencies). The present experiment explored the spatio-temporal characteristics of the spatial frequency modulation of affect-related neural processing, as well as its generalizability to non-facial stimuli. To that aim, the event-related potentials (ERPs) elicited by low-pass filtered (i.e., high spatial frequencies are eliminated) and intact non-facial emotional images were recorded from 31 participants using a 60-electrode array. The earliest significant effect of spatial frequency was observed at 135 ms from stimulus onset: N135 component of the ERPs. In line with previous studies, the origin of N135 was localized at secondary visual areas for low-pass filtered stimuli and at primary areas for intact stimuli. Importantly, this component showed an interaction between spatial frequency and emotional content: within low-pass filtered pictures, negative stimuli elicited the highest N135 amplitudes. By contrast, within intact stimuli, neutral pictures were those eliciting the highest amplitudes. These results suggest that high spatial frequencies are not essential for the initial affect-related processing of visual stimuli, which would mainly rely on low spatial frequency visual information. According to present data, high spatial frequencies would come into play later on.

Friday, November 24, 2006

ARTICLE UPDATE - Is this happiness I see? Biases in the identification of emotional facial expressions in depression and social phobia.

Joormann J, Gotlib IH.

Journal of Abnormal Psychology, 115, 705-714.

The present study was designed to examine the operation of depression-specific biases in the identification or labeling of facial expression of emotions. Participants diagnosed with major depression and social phobia and control participants were presented with faces that expressed increasing degrees of emotional intensity, slowly changing from a neutral to a full-intensity happy, sad, or angry expression. The authors assessed individual differences in the intensity of facial expression of emotion that was required for the participants to accurately identify the emotion being expressed. The depressed participants required significantly greater intensity of emotion than did the social phobic and the control participants to correctly identify happy expressions and less intensity to identify sad than angry expressions. In contrast, social phobic participants needed less intensity to correctly identify the angry expressions than did the depressed and control participants and less intensity to identify angry than sad expressions. Implications of these results for interpersonal functioning in depression and social phobia are discussed.

ARTICLE UPDATE - Green love is ugly: Emotions elicited by synesthetic grapheme-color perceptions.

Callejas A, Acosta A, Lupianez J.

Brain Research, in press

Synesthetes who experience grapheme-color synesthesia often report feeling uneasy when dealing with incongruently colored graphemes although no empirical data is available to confirm this phenomenon. We studied this affective reaction related to synesthetic perceptions by means of an evaluation task. We found that the perception of an incorrectly colored word affects the judgments of emotional valence. Furthermore, this effect competed with the word's emotional valence in a categorization task thus supporting the automatic nature of this synesthetically elicited affective reaction. When manipulating word valence and word color-photism congruence, we found that responses were slower (and less accurate) for inconsistent conditions than for consistent conditions. Inconsistent conditions were defined as those where semantics and color-photism congruence did not produce a similar assessment and therefore gave rise to a negative affective reaction (i.e., positive-valence words presented in a color different from the synesthete's photism or negative-valence words presented in the photism's color). We therefore observed a modulation of the congruency effect (i.e., faster reaction times to congruently colored words than incongruently colored words). Although this congruence effect has been taken as an index of the true experience of synesthesia, we observed that it can be reversed when the experimental manipulations turn an incongruently colored word into a consistent stimulus. To our knowledge, this is the first report of an affective reaction elicited by the congruency between the synesthetically induced color of a word and the color in which the word is actually presented. The underlying neural mechanisms that might be involved in this phenomenon are discussed.

Wednesday, November 22, 2006

ARTICLE UPDATE - Recent fear is resistant to extinction

Stephen Maren and Chun-hui Chang

PNAS, 103, 18020-18025

In some individuals, fearful experiences (e.g., combat) yield persistent and debilitating psychological disturbances, including posttraumatic stress disorder (PTSD). Early intervention (e.g., debriefing) after psychological trauma is widely practiced and argued to be an effective strategy for limiting subsequent psychopathology, although there has been considerable debate on this point. Here we show in an animal model of traumatic fear that early intervention shortly after an aversive experience yields poor long-term fear reduction. Extinction trials administered minutes after aversive fear conditioning in rats suppressed fear acutely, but fear suppression was not maintained the next day. In contrast, delivering extinction trials 1 day after fear conditioning produced an enduring suppression of fear memory. We further show that the recent experience of an aversive event, not the timing of the extinction intervention per se, inhibits the development of long-term fear extinction. These results reveal that the level of fear present at the time of intervention is a critical factor in the efficacy of extinction. Importantly, our work suggests that early intervention may not yield optimal outcomes in reducing posttraumatic stress, particularly after severe trauma.

Tuesday, November 14, 2006

ARTICLE UPDATE - Neural dynamics for facial threat processing as revealed by gamma band synchronization using MEG

Neural dynamics for facial threat processing as revealed by gamma band synchronization using MEG

Qian Luo, Tom Holroyd, Matthew Jones, Talma Hendler, and James Blair

NeuroImage, in press

Facial threat conveys important information about imminent environmental danger. The rapid detection of this information is critical for survival and social interaction. However, due to technical and methodological difficulties, the spatiotemporal profile for facial threat processing is unknown. By utilizing magnetoencephalography (MEG), a brain-imaging technique with superb temporal resolution and fairly good spatial resolution, Synthetic Aperture Magnetometry (SAM), a recently developed source analysis technique, and a sliding window analysis, we identified the spatiotemporal development of facial threat processing in the gamma frequency band. We also tested the dual-route hypothesis by LeDoux who proposed, based on animal research, that there are two routes to the amygdala: a quick subcortical route and a slower and cortical route. Direct evidence with humans supporting this model has been lacking. Moreover, it has been unclear whether the subcortical route responds specifically to fearful expressions or to threatening expressions in general. We found early event-related synchronizations (ERS) in response to fearful faces in the hypothalamus/thalamus area (10–20 ms) and then the amygdala (20–30 ms). This was even earlier than the ERS response seen to fearful faces in visual cortex (40–50 ms). These data support LeDoux's suggestion of a quick, subcortical thamalo-amygdala route. Moreover, this route was specific for fear expressions; the ERS response in the amygdala to angry expressions had a late onset (150–160 ms). The ERS onset in prefrontal cortex followed that seen within the amygdala (around 160–210 ms). This is consistent with its role in higher-level emotional/cognitive processing.

Thursday, November 09, 2006

ARTICLE UPDATE - Mood Alters Amygdala Activation to Sad Distractors During an Attentional Task

Lihong Wang, Kevin S. LaBar and Gregory McCarthy

Biological Psychiatry, 60, 1139-1146

Background

A behavioral hallmark of mood disorders is biased perception and memory for sad events. The amygdala is poised to mediate internal mood and external event processing because of its connections with both the internal milieu and the sensory world. There is little evidence showing that the amygdala’s response to sad sensory stimuli is functionally modulated by mood state, however.
Methods

We investigated the impact of mood on amygdala activation evoked by sad and neutral pictures presented as distractors during an attentional oddball task. Healthy adults underwent functional magnetic resonance imaging during task runs that were preceded by sad or happy movie clips. Happy and sad mood induction was conducted within-subjects on consecutive days in counterbalanced order.
Results

Amygdala activation to sad distractors was enhanced after viewing sad movies relative to happy ones and was correlated with reaction time costs to detect attentional targets. The activation was higher in female subjects in the right hemisphere. The anterior cingulate, ventromedial and orbital prefrontal cortex, insula, and other posterior regions also showed enhanced responses to sad distractors during sad mood.
Conclusions

These findings reveal brain mechanisms that integrate emotional input and current mood state, with implications for understanding cognitive distractibility in depression.

Wednesday, November 08, 2006

ARTICLE UPDATE - Detecting fearful and neutral faces: BOLD latency differences in amygdala–hippocampal junction

A.A.T.S. Reinders, J. Gläscher, J.R. de Jong, A.T.M. Willemsen, J.A. den Boer and C. Büchel

NeuroImage, 33, 805-814

Evolutionary survival and procreation are augmented if an individual organism quickly detects environmental threats and rapidly initiates defensive behavioral reactions. Thus, facial emotions signaling a potential threat, e.g., fear or anger, should be perceived rapidly and automatically, possibly through a subcortical processing route which includes the amygdala. Using event-related functional magnetic resonance imaging (fMRI), we investigated the time course of the response in the amygdala to neutral and fearful faces, which appear from dynamically decreasing random visual noise. We aimed to detect differences of the amygdala response between fearful and neutral faces by estimating the latency of the blood oxygenation level-dependent (BOLD) response. We found that bilateral amygdala–hippocampal junction activation occurred earlier for fearful than for neutral faces. Our findings support the theory of a dual route architecture in which the subcortical thalamic–hippocampal–amygdala route serves fast preconscious threat perception.

ARTICLE UPDATE - A gender- and sexual orientation-dependent spatial attentional effect of invisible images

Yi Jiang, Patricia Costello, Fang Fang, Miner Huang, and Sheng He

PNAS, 103, 17048-17052

Human observers are constantly bombarded with a vast amount of information. Selective attention helps us to quickly process what is important while ignoring the irrelevant. In this study, we demonstrate that information that has not entered observers' consciousness, such as interocularly suppressed (invisible) erotic pictures, can direct the distribution of spatial attention. Furthermore, invisible erotic information can either attract or repel observers' spatial attention depending on their gender and sexual orientation. While unaware of the suppressed pictures, heterosexual males' attention was attracted to invisible female nudes, heterosexual females' attention was attracted to invisible male nudes, gay males behaved similarly to heterosexual females, and gay/bisexual females performed in-between heterosexual males and females.

Friday, November 03, 2006

ARTICLE UPDATE - Emotional modulation of pain: is it the sensation or what we recall?

Godinho F, Magnin M, Frot M, Perchet C, Garcia-Larrea L.

Journal of Neuroscience, 26, 11454-11461

Emotions modulate pain perception, although the mechanisms underlying this phenomenon remain unclear. In this study, we show that intensity reports significantly increased when painful stimuli were concomitant to images showing human pain, whereas pictures with identical emotional values but without somatic content failed to modulate pain. Early somatosensory responses (<200 ms) remained unmodified by emotions. Conversely, late responses showed a significant enhancement associated with increased pain ratings, localized to the right prefrontal, right temporo-occipital junction, and right temporal pole. In contrast to selective attention, which enhances pain ratings by increasing sensory gain, emotions triggered by seeing other people's pain did not alter processing in SI-SII (primary and second somatosensory areas), but may have biased the transfer to, and the representation of pain in short-term memory buffers (prefrontal), as well as the affective assignment to this representation (temporal pole). Memory encoding and recall, rather than sensory processing, appear to be modulated by empathy with others' physical suffering.