Saturday, September 20, 2008

ARTICLE UPDATE - Is emotional contagion special? An fMRI study on neural systems for affective and cognitive empathy.

Nummenmaa L, Hirvonen J, Parkkola R, Hietanen JK.

Neuroimage, in press

Empathy allows us to simulate others' affective and cognitive mental states internally, and it has been proposed that the mirroring or motor representation systems play a key role in such simulation. As emotions are related to important adaptive events linked with benefit or danger, simulating others' emotional states might constitute of a special case of empathy. In this functional magnetic resonance imaging (fMRI) study we tested if emotional versus cognitive empathy would facilitate the recruitment of brain networks involved in motor representation and imitation in healthy volunteers. Participants were presented with photographs depicting people in neutral everyday situations (cognitive empathy blocks), or suffering serious threat or harm (emotional empathy blocks). Participants were instructed to empathize with specified persons depicted in the scenes. Emotional versus cognitive empathy resulted in increased activity in limbic areas involved in emotion processing (thalamus), and also in cortical areas involved in face (fusiform gyrus) and body (extrastriate cortex) perception, as well as in networks associated with mirroring of others' actions (inferior parietal lobule). When brain activation resulting from viewing the scenes was controlled, emotional empathy still engaged the mirror neuron system (premotor cortex) more than cognitive empathy. Further, thalamus and primary somatosensory and motor cortices showed increased functional coupling during emotional versus cognitive empathy. The results suggest that emotional empathy is special. Emotional empathy facilitates somatic, sensory, and motor representation of other peoples' mental states, and results in more vigorous mirroring of the observed mental and bodily states than cognitive empathy.

Sunday, September 14, 2008

ARTICLE UPDATE - The human amygdala is involved in general behavioral relevance detection: Evidence from an event-related functional magnetic resonanc

Ousdal OT, Jensen J, Server A, Hariri AR, Nakstad PH, Andreassen OA.
Neuroscience, in press

The amygdala is classically regarded as a detector of potential threat and as a critical component of the neural circuitry mediating conditioned fear responses. However, it has been reported that the human amygdala responds to multiple expressions of emotions as well as emotionally neutral stimuli of a novel, uncertain or ambiguous nature. Thus, it has been proposed that the function of the amygdala may be of a more general art, i.e. as a detector of behaviorally relevant stimuli [Sander D, Grafman J, Zalla T (2003) The human amygdala: an evolved system for relevance detection. Rev Neurosci 14:303-316]. To investigate this putative function of the amygdala, we used event related functional magnetic resonance imaging (fMRI) and a modified Go-NoGo task composed of behaviorally relevant and irrelevant letter and number stimuli. Analyses revealed bilateral amygdala activation in response to letter stimuli that were behaviorally relevant as compared with letters with less behavioral relevance. Similar results were obtained for relatively infrequent NoGo relevant stimuli as compared with more frequent Go stimuli. Our findings support a role for the human amygdala in general detection of behaviorally relevant stimuli.

ARTICLE UPDATE - Natural selective attention: Orienting and emotion.

Bradley MM.

Psychophysiology, in press

The foundations of orienting and attention are hypothesized to stem from activation of defensive and appetitive motivational systems that evolved to protect and sustain the life of the individual. Motivational activation initiates a cascade of perceptual and motor processes that facilitate the selection of appropriate behavior. Among these are detection of significance, indexed by a late centro-parietal positivity in the event-related potential, enhanced perceptual processing, indexed by a initial cardiac deceleration, and preparation for action, indexed by electrodermal changes. Data exploring the role of stimulus novelty and significance in orienting are presented that indicate different components of the orienting response habituate at different rates. Taken together, it is suggested that orienting is mediated by activation of fundamental motivational systems that have evolved to support survival.

ARTICLE UPDATE - Neural Circuitry Underlying the Regulation of Conditioned Fear and Its Relation to Extinction.

Delgado MR, Nearing KI, Ledoux JE, Phelps EA.

Neuron, 59, 829-838

Recent efforts to translate basic research to the treatment of clinical disorders have led to a growing interest in exploring mechanisms for diminishing fear. This research has emphasized two approaches: extinction of conditioned fear, examined across species; and cognitive emotion regulation, unique to humans. Here, we sought to examine the similarities and differences in the neural mechanisms underlying these two paradigms for diminishing fear. Using an emotion regulation strategy, we examine the neural mechanisms of regulating conditioned fear using fMRI and compare the resulting activation pattern with that observed during classic extinction. Our results suggest that the lateral PFC regions engaged by cognitive emotion regulation strategies may influence the amygdala, diminishing fear through similar vmPFC connections that are thought to inhibit the amygdala during extinction. These findings further suggest that humans may have developed complex cognition that can aid in regulating emotional responses while utilizing phylogenetically shared mechanisms of extinction.

ARTICLE UPDATE - Mapping the Semantic Space for the Subjective Experience of Emotional Responses to Odors.

Chrea C, Grandjean D, Delplanque S, Cayeux I, Le Calvé B, Aymard L, Velazco MI, Sander D, Scherer KR.

Chemical Senses, in press

Two studies were conducted to examine the nature of the verbal labels that describe emotional effects elicited by odors. In Study 1, a list of terms selected for their relevance to describe affective feelings induced by odors was assessed while participants were exposed to a set of odorant samples. The data were submitted to a series of exploratory factor analyses to 1) reduce the set of variables to a smaller set of summary scales and 2) get a preliminary sense of the differentiation of affective feelings elicited by odors. The goal of Study 2 was to replicate the findings of Study 1 with a larger sample of odorant samples and participants and to validate the preliminary model obtained in Study 1 by using confirmatory factor analysis. Overall, the findings point to a structure of affective responses to odors that differs from the classical taxonomies of emotion such as posited by discrete or bidimensional emotion theories. These findings suggest that the subjective affective experiences or feelings induced by odors are structured around a small group of dimensions that reflect the role of olfaction in well-being, social interaction, danger prevention, arousal or relaxation sensations, and conscious recollection of emotional memories.

Sunday, September 07, 2008

ARTICLE UPDATE - Music-induced mood modulates the strength of emotional negativity bias: An ERP study.

Chen J, Yuan J, Huang H, Chen C, Li H.

Neuroscience Letters, in press,

The present study investigated the effect of music-elicited moods on the subsequent affective processing through a music-primed valence categorization task. Event-related potentials were recorded for positive and negative emotional pictures that were primed by happy or sad music excerpts. The reaction time data revealed longer reaction times (RTs) for pictures following negative versus positive music pieces, irrespective of the valence of the picture. Additionally, positive pictures elicited faster response latencies than negative pictures, irrespective of the valence of the musical prime. Moreover, the main effect of picture valence, and the music by picture valence interaction effect were both significant for P2 amplitudes and for the averaged amplitudes at 500-700ms interval. Negative pictures elicited smaller P2 amplitudes than positive pictures, and the amplitude differences between negative and positive pictures were larger with negative musical primes than with positive musical primes. Similarly, compared to positive pictures, negative pictures elicited more negative deflections during the 500-700ms interval across prime types. The amplitude differences between negative and positive pictures were again larger under negative versus positive music primes at this interval. Therefore, the present study observed a clear emotional negativity bias during either prime condition, and extended the previous findings by showing increased strength of the negative bias under negative mood primes. This suggests that the neural sensitivity of the brain to negative stimuli varies with individuals' mood states, and this bias is particularly intensified by negative mood states.

Monday, September 01, 2008

ARTICLE UPDATE - Visual search for faces with emotional expressions.

Frischen A, Eastwood JD, Smilek D.

Psychological Bulletin, 134, 662-676

The goal of this review is to critically examine contradictory findings in the study of visual search for emotionally expressive faces. Several key issues are addressed: Can emotional faces be processed preattentively and guide attention? What properties of these faces influence search efficiency? Is search moderated by the emotional state of the observer? The authors argue that the evidence is consistent with claims that (a) preattentive search processes are sensitive to and influenced by facial expressions of emotion, (b) attention guidance is influenced by a dynamic interplay of emotional and perceptual factors, and (c) visual search for emotional faces is influenced by the emotional state of the observer to some extent. The authors also argue that the way in which contextual factors interact to determine search performance needs to be explored further to draw sound conclusions about the precise influence of emotional expressions on search efficiency. Methodological considerations (e.g., set size, distractor background, task set) and ecological limitations of the visual search task are discussed. Finally, specific recommendations are made for future research directions.

ARTICLE UPDATE - Individual differences in learning the affective value of others under minimal conditions.

Bliss-Moreau E, Barrett LF, Wright CI.

Emotion, 8, 479-493.

This paper provides the first demonstration that people can learn about the positive and negative value of other people (e.g., neutral faces) under minimal learning conditions, with stable individual differences in this learning. In four studies, participants viewed neutral faces paired with sentences describing positive, negative or neutral behaviors on either two (Study 1) or four (Studies 2, 3, and 4) occasions. Participants were later asked to judge the valence of the faces alone. Studies 1 and 2 demonstrated that learning does occur under minimal conditions. Study 3 and 4 further demonstrated that the degree of learning was moderated by Extraversion. Finally, Study 4 demonstrated that initial learning persisted over a period of 2 days. Implications for affective processing and person perception are discussed.

ARTICLE UPDATE - Emotion Theory and Research: Highlights, Unanswered Questions, and Emerging Issues.

Izard CE.

Annual Review of Psychology, in press

Emotion feeling is a phase of neurobiological activity, the key component of emotions and emotion-cognition interactions. Emotion schemas, the most frequently occurring emotion experiences, are dynamic emotion-cognition interactions that may consist of momentary/ situational responding or enduring traits of personality that emerge over developmental time. Emotions play a critical role in the evolution of consciousness and the operations of all mental processes. Types of emotion relate differentially to types or levels of consciousness. Unbridled imagination and the ability for sympathetic regulation of empathy may represent both potential gains and losses from the evolution and ontogeny of emotion processes and consciousness. Unresolved issues include psychology’s neglect of levels of consciousness that are distinct from access or reflective consciousness and use of the term “unconscious mind” as a dumpster for all mental processes that are considered unreportable. The relation of memes and the mirror neuron system to empathy, sympathy, and cultural influences on the development of socioemotional skills are unresolved issues destined to attract future research.

ARTICLE UPDATE - Differential Influences of Emotion, Task, and Novelty on Brain Regions Underlying the Processing of Speech Melody.

Ethofer T, Kreifelts B, Wiethoff S, Wolf J, Grodd W, Vuilleumier P, Wildgruber D.

The Journal of Cognitive Neuroscience, in press

Abstract We investigated the functional characteristics of brain regions implicated in processing of speech melody by presenting words spoken in either neutral or angry prosody during a functional magnetic resonance imaging experiment using a factorial habituation design. Subjects judged either affective prosody or word class for these vocal stimuli, which could be heard for either the first, second, or third time. Voice-sensitive temporal cortices, as well as the amygdala, insula, and mediodorsal thalami, reacted stronger to angry than to neutral prosody. These stimulus-driven effects were not influenced by the task, suggesting that these brain structures are automatically engaged during processing of emotional information in the voice and operate relatively independent of cognitive demands. By contrast, the right middle temporal gyrus and the bilateral orbito-frontal cortices (OFC) responded stronger during emotion than word classification, but were also sensitive to anger expressed by the voices, suggesting that some perceptual aspects of prosody are also encoded within these regions subserving explicit processing of vocal emotion. The bilateral OFC showed a selective modulation by emotion and repetition, with particularly pronounced responses to angry prosody during the first presentation only, indicating a critical role of the OFC in detection of vocal information that is both novel and behaviorally relevant. These results converge with previous findings obtained for angry faces and suggest a general involvement of the OFC for recognition of anger irrespective of the sensory modality. Taken together, our study reveals that different aspects of voice stimuli and perceptual demands modulate distinct areas involved in the processing of emotional prosody.