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Vocal and visual stimulation, congruence and lateralization affect brain oscillations in inter-species emotional positive and negative interactions
Abstract
The present research explored the effect of cross-modal integration of emotional cues (auditory and visual AV) compared with only visual (V) emotional cues in observing inter-species interactions. The brain activity was monitored when subjects processed AV and V situations which represented an emotional (positive or negative), inter-species (human-animal) interactions. Congruence (emotionally congruous or incongruous visual and auditory patterns) was also modulated. EEG brain oscillations (from delta to beta) were analyzed and the cortical source localization (by sLORETA) was applied to the data. Frequency band (mainly low-frequency delta and theta) showed a significant brain activity increasing in response to negative compared to positive interactions within the right hemisphere. Moreover, differences were found based on stimulation type, with an increased effect for AV compared with V. Finally, delta band supported a lateralized right DLPFC activity in response to negative and incongruous inter-species interactions, mainly for AV. The contribution of cross-modality, congruence (incongruous patterns) and lateralization (right DLPFC) in response to inter-species emotional interactions was discussed at light of a "negative lateralized effect".
... Animal auditory lateralization has been studied employing different techniques that directly analyse brain hemispheres' activity (e.g. functional magnetic resonance imaging (fMRI) 26 , positron emission tomography (PET) 3 and electroencephalography (EEG) 27,28 ) or by using the head-turning paradigm, which measures an animal preferential use of one ear/eye to attend to a stimulus (e.g. 9,21 ). ...
... Functional asymmetries for emotional processing have also been described in human studies, which employed the EEG technique 18,28 . It has been found that the emotional valence affects brain oscillations: in dogs or cats confronted to audio-visual stimuli showing negative in incongruous interspecies (human-pet) interactions, EEG measures revealed more delta waves in the right hemisphere 28 . ...
... Functional asymmetries for emotional processing have also been described in human studies, which employed the EEG technique 18,28 . It has been found that the emotional valence affects brain oscillations: in dogs or cats confronted to audio-visual stimuli showing negative in incongruous interspecies (human-pet) interactions, EEG measures revealed more delta waves in the right hemisphere 28 . ...
Brain lateralization is a phenomenon widely reported in the animal kingdom and sensory laterality has been shown to be an indicator of the appraisal of the stimulus valence by an individual. This can prove a useful tool to investigate how animals perceive intra- or hetero-specific signals. The human-animal relationship provides an interesting framework for testing the impact of the valence of interactions on emotional memories. In the present study, we tested whether horses could associate individual human voices with past positive or negative experiences. Both behavioural and electroencephalographic measures allowed examining laterality patterns in addition to the behavioural reactions. The results show that horses reacted to voices associated with past positive experiences with increased attention/arousal (gamma oscillations in the right hemisphere) and indicators of a positive emotional state (left hemisphere activation and ears held forward), and to those associated with past negative experiences with negative affective states (right hemisphere activation and ears held backwards). The responses were further influenced by the animals’ management conditions (e.g. box or pasture). Overall, these results, associating brain and behaviour analysis, clearly demonstrate that horses’ representation of human voices is modulated by the valence of prior horse-human interactions.
... A number of studies have investigated how neural oscillations in different frequency bands, primarily delta (1− 3 Hz), theta (4− 7 Hz), alpha (8− 13 Hz), and beta (15− 25 Hz), support integration of audiovisual affective signals ( Table 1). Some of these studies have compared time-frequency activity for audiovisual stimulation with a unimodal visual or unimodal auditory condition (Balconi & Vanutelli, 2016;Baumgartner, Esslen, & Jäncke, 2006;Jessen, 2012). However, this approach is limited as the results are confounded by the activity of the non-subtracted unimodal condition. ...
... Evoked activity reflects phase-dependent brain responses that are time-locked to the onset of a presented stimulus; whereas, induced activity reflects oscillations that are elicited by the presented stimulus but are phaseindependent and thus are removed through the standard averaging process. Previous studies have mainly focused on either total power, the composite of evoked and induced activity, or evoked power (e.g., Balconi & Vanutelli, 2016;Baumgartner et al., 2006). Examining induced activity is especially important when naturalistic dynamic stimuli are used because stimulus information is temporally unfolding but is not necessarily phase-locked to the onset of stimulus. ...
Our affective experiences are influenced by combined multisensory information. Although the enhanced effects of congruent audiovisual information on our affective experiences have been well documented, the role of neural oscillations in the audiovisual integration of affective signals remains unclear. First, it is unclear whether oscillatory activity changes as a function of valence. Second, the function of phase-locked and non-phase-locked power changes in audiovisual integration of affect has not yet been clearly distinguished. To fill this gap, the present study performed time-frequency analyses on EEG data acquired while participants perceived positive, neutral and negative naturalistic video and music clips. A comparison between the congruent audiovisual condition and the sum of unimodal conditions was used to identify supra-additive (Audiovisual > Visual + Auditory) or sub-additive (Audiovisual < Visual + Auditory) integration effects. The results showed that early evoked sub-additive theta and sustained induced supra-additive delta and beta activities are linked to audiovisual integration of affect regardless of affective content.
... In particular, blocks 1, 2 and 3 required participants to perform a task consisting of a selective attention game to be played in cooperation. The task represented a modified version of a previous validated version of the task 33,39,64,65 , in which we have opted for a cooperative condition with a specific moment of gifts exchange. In particular, the task was administered through the use of the E-Prime 2.0 software (E-prime2 software, Psychology Software Tools Inc., Sharpsburg, PA, USA), and required participants to memorize a target stimulus (green or blue triangle or circle) which was to be subsequently recognized among other stimuli, by pressing the left/right keys on the computer keyboard. ...
... Indeed, as demonstrated by previous studies 35,64,65 , the presence of a greater interpersonal link and cohesion lead to the implementation of a synergistic and cooperative behavior increasing the adoption of common O2Hb intra-brain connectivity representation, from left to right, in order 1 for block 1, 2 and 3. The red area represents the increase of O2Hb intra-brain connectivity in DLPFC area. ...
The gift exchange represents a moment that characterizes interpersonal interactions. In particular, research in psychological and neuroscientific fields aimed to observe the social function of gift exchange. Specifically, the present study aimed to investigate the effects of prosocial behavior, experienced during gift exchange, on individuals’ cognitive performance and brain activity. To this aim, behavioral performance and neural activity of 15 dyads of participants, with a consolidated friendship, were collected during the execution of an attentional cooperative task before or after a gift exchange. Individuals’ brain activity was recorded through the use of Functional Near Infrared Spectroscopy (fNIRS) in hyperscanning. Results showed an increase of perceived cooperation and cognitive performance, in terms of accuracy (ACC), after gift exchange. The increase of interpersonal tuning and cooperation was also shown by neural activity with an increase of oxygenated hemoglobin (O2Hb) intra-brain and inter-brain connectivity in the dorsolateral prefrontal cortex (DLPFC) following the gift exchange. Moreover, from ConIndex analysis emerged an increase of inter-brain connectivity compared to intra-brain in DLPFC area. The present study, therefore, highlights how prosocial behavior can have positive effects on cognitive performance improvement and interpersonal relationships and neural coordination strengthen, increasing intra and inter-brain connectivity mechanisms.
... Frequency domain: power spectral density, band power >> using Fourier Transform 29 [26,49,63,74,104,105,107,116,123,149,161,169,176,193,197,200,203,204,207,208,216,[218][219][220][221][222][223][224][225] Time domain: Activity, mobility and complexity >> using Hjorth Parameters, Fractal dimension >> using Higuchi Method 11 [107,117,200,203,204,206,213,216,220,222,224] Wavelet domain: Entropy, Energy >> using Wavelet Transform 7 [186,201,203,213,216,217,226] Statistical features: Median, Standard deviation, Kurtosis symmetry, etc. 6 [6,104,117,200,204,226] Classification Support Vector Machine (SVM) 24 [49,104,106,107,116,117,157,176,186,190,193,196,197,[202][203][204]213,216,218,220,[225][226][227][228] K-Nearest Neighbor (k-NN) 10 [49,104,107,190,204,207,213,216,218,228] Linear Discriminant Analysis (LDA) 4 [26,123,176,227] Artificial Neural Network (ANN) 7 [105,176,190,204,216,223,227] It is noteworthy to mention that a single feature extraction technique is not optimal across all of the applications. Besides, existing signals are not enough for high accuracy feature extraction. ...
... [ [26][27][28][29][30][31][32]35,43,45,46,48,51,55,56,59,60,64,65,[67][68][69][70]74,77,78,80,[82][83][84][85][86][87]89,91,93,96,97,113,[127][128][129]132,134,138,139,[141][142][143][144]147,148,150,155,158,159,161,163,164,166,[169][170][171][172]175,[177][178][179]182,184,187,192,210,215, New method These articles proposed approaches for detecting affective states using single/multi-modality signal processing methods, including feature extraction and selection, machine learning and pattern recognition methods. These proposed systems aim to explore or improve EEG-based emotion recognition systems. ...
Recent developments and studies in brain-computer interface (BCI) technologies have facilitated emotion detection and classification. Many BCI studies have sought to investigate, detect, and recognize participants’ emotional affective states. The applied domains for these studies are varied, and include such fields as communication, education, entertainment, and medicine. To understand trends in electroencephalography (EEG)-based emotion recognition system research and to provide practitioners and researchers with insights into and future directions for emotion recognition systems, this study set out to review published articles on emotion detection, recognition, and classification. The study also reviews current and future trends and discusses how these trends may impact researchers and practitioners alike. We reviewed 285 articles, of which 160 were refereed journal articles that were published since the inception of affective computing research. The articles were classified based on a scheme consisting of two categories: research orientation and domains/applications. Our results show considerable growth of EEG-based emotion detection journal publications. This growth reflects an increased research interest in EEG-based emotion detection as a salient and legitimate research area. Such factors as the proliferation of wireless EEG devices, advances in computational intelligence techniques, and machine learning spurred this growth.
... The emotions of individuals, therefore, represent overlapping experiences that are cognitively interpreted in order to identify the responses and neurophysiological changes in the valence and arousal dimensions organized based on different eliciting factors, as different contexts and stimuli, autobiographical memories, and semantic representation or behavioral responses (Russell, 2003;Balconi and Vanutelli, 2016;Balconi et al., 2017). ...
... Moreover, further studies will be necessary to investigate the lateralization effect we found in relation to the different frequency bands and the possible specific role of Delta and Theta oscillations in left frontal structures as a possible marker of processing the emotional valence of consumers' experience. Indeed, frontal and prefrontal cortex lateralization has been previously related to cognitive control over emotional stimuli and emotional behavior in basic research and in studies on cross-modal integration of emotional cues (Balconi et al., 2015;Balconi and Vanutelli, 2016). In past neuromarketing studies, a left prefrontal cortex activation toward commercial advertising was interpreted as an index of positive emotions and consumers' preference (Balconi et al., 2014b;Leanza and Balconi, 2017). ...
To gain a deeper understanding of consumers' brain responses during a real-time in-store exploration could help retailers to get much closer to costumers' experience. To our knowledge, this is the first time the specific role of touch has been investigated by means of a neuroscientific approach during consumer in-store experience within the field of sensory marketing. This study explores the presence of distinct cortical brain oscillations in consumers' brain while navigating a store that provides a high level of sensory arousal and being allowed or not to touch products. A 16-channel wireless electroencephalogram (EEG) was applied to 23 healthy participants (mean age = 24.57 years, SD = 3.54), with interest in cosmetics but naive about the store explored. Subjects were assigned to two experimental conditions based on the chance of touching or not touching the products. Cortical oscillations were explored by means of power spectral analysis of the following frequency bands: delta, theta, alpha, and beta. Results highlighted the presence of delta, theta, and beta bands within the frontal brain regions during both sensory conditions. The absence of touch was experienced as a lack of perception that needs cognitive control, as reflected by Delta and Theta band left activation, whereas a right increase of Beta band for touch condition was associated with sustained awareness on the sensory experience. Overall, EEG cortical oscillations' functional meaning could help highlight the neurophysiological implicit responses to tactile conditions and the importance of touch integration in consumers' experience.
... Regarding theta activity, instead, a greater theta brain responsiveness can be related to an increase of individuals' motivational and emotional response and affective arousal experienced during hotel environments exploration (Adolphs, 1999;Balconi & Vanutelli, 2016Balconi et al., 2015;Leanza et al., 2015). This result is supported by previous studies that have demonstrated the involvement of the theta band in the processes of emotional evaluation and emotional engagement in response to salient stimuli Knyazev, 2007;Leanza et al., 2015). ...
Hoteliers and companies are asked to optimize their budgets and, at the same time, gifting unforgettable experiences to customers who are freely able to express their feedbacks, readable by thousands of potential guests. In addition, the rise of corporate social responsibility (CSR), sustainability, environmental and social issues leads to the necessity to investigate more systematically new business models that respond to these emerging concerns. In order to investigate the impact of sustainability in tourism marketing, a multimethod neuroscientific approach was used to record individuals’ neural activity (electroencephalography, EEG) and autonomic system responses during the exploration of four different environments of a green hotel adopting a sustainability approach. EEG findings showed an increase of beta and theta frequency band activity during individuals’ environments exploration, underlying the presence of cognitive and emotional elaboration processes. Moreover, from autonomic activity, an increase of pulse volume amplitude (PVA) and heart rate (HR) response emerged during the exploration of hotel environments, highlighting emotional engagement and positive emotional response. This research, therefore, contributes to show how responsiveness to sustainability concept within consumer services can improve individuals’ experience enjoyment and customers' well-being condition.
... Moreover, gift exchange, developing solid and functional interpersonal relationships, enhance individuals' cooperative attitudes by increasing the sense and the perception of social recognition and enhancing a collective comparison [26]. Cooperation, indeed, can reinforce the sense of social inclusion and interpersonal cohesion thanks to the implementation of joint actions [27,28]. ...
Background:
Recently several studies in the psychological and social field have investigated the social function of gift exchange as a useful way for the consolidation of interpersonal and social relationships and the implementation of prosocial behaviors. Specifically, the present research wanted to explore if gift exchange, increased emotional sharing, gratitude and interpersonal cooperation, leading to an improvement in cognitive and behavioral performance. In this regard, neural connectivity and cognitive performance of 14 pairs of friends were recorded during the development of a joint attention task that involved a gift exchange at the beginning or halfway through the task. The moment of gift exchange was randomized within the pairs: for seven couples, it happened at task beginning, for the remaining seven later. Individuals' simultaneous brain activity was recorded through the use of two electroencephalograms (EEG) systems that were used in hyperscanning.
Results:
The results showed that after gift exchange there was an improvement in behavioral performance in terms of accuracy. For what concerns EEG, instead, an increase of delta and theta activation was observed in the dorsolateral prefrontal cortex (DLPFC) when gift exchange occurred at the beginning of the task. Furthermore, an increase in neural connectivity for delta and theta bands was observed.
Conclusion:
The present research provides a significant contribution to the exploration of the factors contributing to the strengthening of social bonds, increasing cooperation, gratitude and prosocial behavior.
... This result is in line with what hypothesized concerning the role of gratitude in reinforcing the specific effect of cooperation as it was perceived by the subjects. In fact, previous studies underlined how the presence of a closer interpersonal bond can affect the cognitive level and, therefore, the behavioral responses (Cui et al., 2012;Chung et al., 2015;Balconi and Vanutelli, 2016b;Vanutelli et al., 2017;Balconi et al., 2018). In fact, cooperation implies the ability to adopt common strategies due to some psychological mechanisms, such as perceived self-efficacy, empathy and motivational components that create synergistic actions (Rumble et al., 2010). ...
Recently, different psychological studies have been interested in identifying the factors that regulate the development and maintenance of long-lasting interpersonal and social relationships. Specifically, the present research explored the link between gifts exchange, gratitude, and cognitive effects. The behavioral performance and neural activity of 32 participants were recorded during a cooperative game to be played before and after gifts exchange. Specifically, participants had to perform the task coupled with a dear friend. Half of the couples were asked to exchange a gift before the task performance; the other half was asked to exchange a gift halfway through the task performance. For hemodynamic brain responses, functional near-infrared spectroscopy (fNIRS) was used. Results showed that an increase in cognitive performance occurred after the exchange of gifts, with improved accuracy and lower response times in task performance. Regarding hemodynamic responses, an increase in oxygenated hemoglobin (O2Hb) was detected, especially in the dorsolateral prefrontal cortex (DLPFC) following the gift exchange. Furthermore, it was observed that gift exchange before the beginning of the task increased the performance level. The present study provides a significant contribution to the identification of those factors that enable the increased cognitive performance based on cooperative relationships.
... For example, dogs processed "happy" human voices with the LH, but they also showed a lower arousal for these voices than those reflecting fear [66]. There is more activation of RH when humans watch incongruent audio-visual interactions on videos [81], and incongruence is known to stimulate attention [82]. Alertness overall tends to increase for both salient or more negative interpersonal conditions [83] consider that the arousal elicited by auditory stimuli is more important than their specific valence. ...
Studies on auditory laterality have revealed asymmetries for processing, particularly species-specific signals, in vertebrates and that each hemisphere may process different features according to their functional “value”. Processing of novel, intense emotion-inducing or finer individual features may require attention and we hypothesised that the “functional pertinence” of the stimuli may be modulating attentional processes and hence lateralisation of sound processing. Behavioural measures in “(food) distracted” captive Campbell’s monkeys and electrophysiological recordings in anesthetised (versus awake) European starlings were performed during the broadcast of auditory stimuli with different functional “saliences” (e.g., familiar/novel). In Campbell’s monkeys, only novel sounds elicited lateralised responses, with a right hemisphere preference. Unfamiliar sounds elicited more head movements, reflecting enhanced attention, whereas familiar (usual in the home environment) sounds elicited few responses, and thus might not be arousing enough to stimulate attention. In starlings, in field L, when awake, individual identity was processed more in the right hemisphere, whereas, when anaesthetised, the left hemisphere was more involved in processing potentially socially meaningless sounds. These results suggest that the attention-getting property of stimuli may be an adapted concept for explaining hemispheric auditory specialisation. An attention-based model may reconcile the different existing hypotheses of a Right Hemisphere-arousal/intensity or individual based lateralisation.
... However, limited research used visual data sources, including photographs and videos (Ray & Smith, 2012). Visual methodology, especially for cognitive researchers seeking to capture emotional content using unobtrusive measures (e.g., Balconi & Vanutelli, 2016), might be a potential and promising research opportunity. ...
... Indeed, previous work highlighted that event-related theta activity signal sustained visual stimulation with affective content [44,46,53,73] when coordinated responses are needed to guarantee alertness and readiness. Specifically, it was shown that, when dealing with attentive functions, theta activity is mainly localized over frontal sites. ...
Background
Cooperation and competition were compared in the present study. Brain correlates (electroencephalography, EEG frequency band, delta, theta, alpha, and beta) and hemodynamic measure of functional near-infrared spectroscopy (fNIRS, O2Hb) were acquired during a joined cooperative (Experiment 1) or competitive (Experiment 2) task. Subjects were required to match each other’s cognitive performance (cooperation) or to make better than others (competition) in terms of accuracy (error rate, ER) and response time (RT). In addition, a personality trait measure (behavioral activation system, BAS) was used to distinguish subjects based on their rewarding attitude. Self-perception of social ranking and real performance were considered in response to subjects’ performance (that was artificially manipulated to show an increasing or decreasing profile during the task).
Results
An increased left prefrontal cortical (PFC) responsiveness was found for subjects who had higher BAS rating in case of both cooperation and competition conditions. Moreover, subjects with higher BAS ratings showed greater frontal left activity during the cooperative task. These subjects also concomitantly perceived an increasing in social ranking and improved their performance.
Conclusions
Present results demonstrated that some trait components (BAS) and cooperative condition induce a positive self-representation in term of ranking and a best way to perform the task, as underlined by self-perception and cognitive outcomes. Indeed the higher BAS trait proved to be related with the representation of higher social ranking and with the perception of improved cognitive outcomes, with also a significant increased left PFC activity in cooperative contexts.
... While many studies have tested for the effects on emotion perception of one modality on the other, relatively few studies have investigated how audiovisual integration might influence affective experience depending on whether the valence in one modality matches the valence in the other (Balconi & Vanutelli, 2016b;Baumgartner, Esslen, & Jäncke, 2006;Ellis & Simons, 2005;Gerdes et al., 2013;Spreckelmeyer, Kutas, Urbach, Altenmüller, & Münte, 2006). The focus of the current studies is on the integrated general affective state resulting from experiencing affective information that is congruent or incongruent across modalities (visual and auditory). ...
Two experiments examined how affective values from visual and auditory modalities are integrated. Experiment 1 paired music and videos drawn from three levels of valence while holding arousal constant. Experiment 2 included a parallel combination of three levels of arousal while holding valence constant. In each experiment, participants rated their affective states after unimodal and multimodal presentations. Experiment 1 revealed a congruency effect in which stimulus combinations of the same extreme valence resulted in more extreme state ratings than component stimuli presented in isolation. An interaction between music and video valence reflected the greater influence of negative affect. Video valence was found to have a significantly greater effect on combined ratings than music valence. The pattern of data was explained by a five parameter differential weight averaging model that attributed greater weight to the visual modality and increased weight with decreasing values of valence. Experiment 2 revealed a congruency effect only for high arousal combinations and no interaction effects. This pattern was explained by a three parameter constant weight averaging model with greater weight for the auditory modality and a very low arousal value for the initial state. These results demonstrate key differences in audiovisual integration between valence and arousal.
Home automation brings together technology, engineering, and user experience (UX). Within this framework, even neuroscience could be a valuable discipline to explore UX. For the first time, in the present work, some distinguishing effects of domotics on users’ cognitive and emotional behavior are highlighted by using the neuroscientific approach. In order to define possible effects of a smart home system (SHS) on UX, a neuroscientific multimethodology was adopted with the purpose of recording and confronting the neural activity (electroencephalography, EEG) and autonomic system responses of 19 individuals during a resting state (RS) baseline and the exploration of five different tech-interaction areas in a domotic environment. EEG findings showed a generalized neural activation reflected by alpha band activity while participants were exploring the tech areas confronted with the RS. The delta band was mainly present in temporo-central compared to frontal and parieto-occipital areas and was interpreted as a higher emotional activation related to the whole UX. This effect was found for the sixth tech-interaction area (i.e., bedroom) compared to the RS, and it is supposed to represent an enhanced emotional response and integration processing toward a higher multisensory interactive area. Regarding autonomic activity, an increase in heart rate (HR) was found for the bedroom area compared to the RS, thus showing a specific effect on physiological indices in this engaging tech area. The present research constitutes the first attempt to understand the user responsiveness to SHS, in terms of cognitive and emotional engagement, by adopting a neuroscientific perspective. Some high-value benefits derived from this approach will be described in light of the neurophysiological results.
The brain activity, considered in its hemodynamic (optical imaging: functional Near-Infrared Spectroscopy, fNIRS) and electrophysiological components (event-related potentials, ERPs, N200) was monitored when subjects observed (visual stimulation, V) or observed and heard (visual + auditory stimulation, VU) situations which represented inter-species (human-animal) interactions, with an emotional positive (cooperative) or negative (uncooperative) content. In addition, the cortical lateralization effect (more left or right dorsolateral prefrontal cortex, DLPFC) was explored. Both ERP and fNIRS showed significant effects due to emotional interactions which were discussed at light of cross-modal integration effects. The significance of inter-species effect for the emotional behavior was considered. In addition, hemodynamic and EEG consonant results and their value as integrated measures were discussed at light of valence effect.
Addressing shortcomings of the self-report Toronto Alexithymia Scale (TAS), two studies were conducted to reconstruct the item domain of the scale. The first study resulted in the development of a new twenty-item version of the scale—the TAS-20. The TAS-20 demonstrated good internal consistency and test-retest reliability, and a three-factor structure theoretically congruent with the alexithymia construct. The stability and replicability of this three-factor structure were demonstrated in the second study with both clinical and nonclinical populations by the use of confirmatory factor analysis.
Using recent regional brain activation/emotion models as a theoretical framework, we examined whether the pattern of regional EEG activity distinguished emotions induced by musical excerpts which were known to vary in affective valence (i.e., positive vs. negative) and intensity (i.e., intense vs. calm) in a group of under- graduates. We found that the pattern of asymmetrical frontal EEG activity dis- tinguished valence of the musical excerpts. Subjects exhibited greater relative left frontal EEG activity to joy and happy musical excerpts and greater relative right frontal EEG activity to fear and sad musical excerpts. We also found that, although the pattern of frontal EEG asymmetry did not distinguish the intensity of the emotions, the pattern of overall frontal EEG activity did, with the amount of frontal activity decreasing from fear to joy to happy to sad excerpts. These data appear to be the first to distinguish valence and intensity of musical emotions on frontal electrocortical measures.
The human ability to perceive and understand others' suffering is critical to reinforcing and maintaining our social bonds. What is not clear, however, is the extent to which this generalizes to nonhuman entities. Anecdotal evidence indicates that people may engage in empathy-like processes when observing suffering nonhuman entities, but psychological research suggests that we more readily empathize with those to whom we are closer and more similar. In this research, we examined neural responses in participants while they were presented with pictures of human versus dog suffering. We found that viewing human and animal suffering led to large overlapping regions of activation previously implicated in empathic responding to suffering, including the anterior cingulate gyrus and anterior insula. Direct comparisons of viewing human and animal suffering also revealed differences such that human suffering yielded significantly greater medial prefrontal activation, consistent with high-level theory of mind, whereas animal suffering yielded significantly greater parietal and inferior frontal activation, consistent with more semantic evaluation and perceptual simulation.
In this study we analyze whether facial expression recognition is marked by specific event-related potential (ERP) correlates and whether conscious and unconscious elaboration of emotional facial stimuli are qualitatively different processes. ERPs elicited by supraliminal and subliminal (10ms) stimuli were recorded when subjects were viewing emotional facial expressions of four emotions or neutral stimuli. Two ERP effects (N2 and P3) were analyzed in terms of their peak amplitude and latency variations. An emotional specificity was observed for the negative deflection N2, whereas P3 was not affected by the content of the stimulus (emotional or neutral). Unaware information processing proved to be quite similar to aware processing in terms of peak morphology but not of latency. A major result of this research was that unconscious stimulation produced a more delayed peak variation than conscious stimulation did. Also, a more posterior distribution of the ERP was found for N2 as a function of emotional content of the stimulus. On the contrary, cortical lateralization (right/left) was not correlated to conscious/unconscious stimulation. The functional significance of our results is underlined in terms of subliminal effect and emotion recognition. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
Objective:
The present study aimed at examining the time course and topography of oscillatory brain activity and event-related potentials (ERPs) in response to laterally presented affective pictures.
Methods:
Electroencephalography was recorded from 129 electrodes in 10 healthy university students during presentation of pictures from the international affective picture system. Frequency measures and ERPs were obtained for pleasant, neutral, and unpleasant pictures.
Results:
In accordance with previous reports, a modulation of the late positive ERP wave at parietal recording sites was found as a function of emotional arousal. Early mid gamma band activity (GBA; 30-45 Hz) at 80 ms post-stimulus was enhanced in response to aversive stimuli only, whereas the higher GBA (46-65 Hz) at 500 ms showed an enhancement of arousing, compared to neutral pictures. ERP and late gamma effects showed a pronounced right-hemisphere preponderance, but differed in terms of topographical distribution.
Conclusions:
Late gamma activity may represent a correlate of widespread cortical networks processing different aspects of emotionally arousing visual objects. In contrast, differences between affective categories in early gamma activity might reflect fast detection of aversive stimulus features.
Addressing shortcomings of the self-report Toronto Alexithymia Scale (TAS), two studies were conducted to reconstruct the item domain of the scale. The first study resulted in the development of a new twenty-item version of the scale--the TAS-20. The TAS-20 demonstrated good internal consistency and test-retest reliability, and a three-factor structure theoretically congruent with the alexithymia construct. The stability and replicability of this three-factor structure were demonstrated in the second study with both clinical and nonclinical populations by the use of confirmatory factor analysis.
Judgement of the emotional tone of a spoken utterance is influenced by a simultaneously presented face expression. The time course of this integration was investigated by measuring the mismatch negativity (MMN). In one condition, the standard stimulus was an angry voice fragment combined with a (congruous) angry face expression. In the deviant pair, the voice expression was kept the same and only the face expression changed to an (incongruous) sad face. The pairs with a deviant visual item evoked a negative electric brain response showing the characteristics of the MMN, which is usually evoked only by auditory deviations. Similar results were obtained by employing incongruous standard and congruous deviant pairs. These findings provide compelling evidence of an early integration of face with voice information in the processing of affect.
Humans share with animals a primitive neural system for processing emotions such as fear and anger. Unlike other animals, humans have the unique ability to control and modulate instinctive emotional reactions through intellectual processes such as reasoning, rationalizing, and labeling our experiences. This study used functional MRI to identify the neural networks underlying this ability. Subjects either matched the affect of one of two faces to that of a simultaneously presented target face (a perceptual task) or identified the affect of a target face by choosing one of two simultaneously presented linguistic labels (an intellectual task). Matching angry or frightened expressions was associated with increased regional cerebral blood flow (rCBF) in the left and right amygdala, the brain's primary fear centers. Labeling these same expressions was associated with a diminished rCBF response in the amygdalae. This decrease correlated with a simultaneous increase in rCBF in the right prefrontal cortex, a neocortical region implicated in regulating emotional responses. These results provide evidence for a network in which higher regions attenuate emotional responses at the most fundamental levels in the brain and suggest a neural basis for modulating emotional experience through interpretation and labeling.
Functional neuroimaging experiments have shown that recognition of emotional expressions does not depend on awareness of visual stimuli and that unseen fear stimuli can activate the amygdala via a colliculopulvinar pathway. Perception of emotional expressions in the absence of awareness in normal subjects has some similarities with the unconscious recognition of visual stimuli which is well documented in patients with striate cortex lesions (blindsight). Presumably in these patients residual vision engages alternative extra-striate routes such as the superior colliculus and pulvinar. Against this background, we conjectured that a blindsight subject (GY) might recognize facial expressions presented in his blind field. The present study now provides direct evidence for this claim.
At the heart of emotion, mood, and any other emotionally charged event are states experienced as simply feeling good or bad, energized or enervated. These states - called core affect - influence reflexes, perception, cognition, and behavior and are influenced by many causes internal and external, but people have no direct access to these causal connections. Core affect can therefore be experienced as free-floating (mood) or can be attributed to some cause (and thereby begin an emotional episode). These basic processes spawn a broad framework that includes perception of the core-affect-altering properties of stimuli, motives, empathy, emotional meta-experience, and affect versus emotion regulation; it accounts for prototypical emotional episodes, such as fear and anger, as core affect attributed to something plus various nonemotional processes.
This book establishes a brain theory based on neural oscillations with a temporal relation to a well-defined event. New findings about oscillations at the cellular level show striking parallels with EEG and MEG measurements. The authors embrace both the level of single neurons and that of the brain as a whole, showing how this approach advances our knowledge about the functional significance of the brain's electrical activity. They are related to sensory and cognitive tasks, leading towards an "integrative neurophysiology". The book will appeal to scientists and graduate students.
This two-volume treatise has the special features that:
- powerful mathematical algorithms are used;
- concepts of synergetics, synchronization of cell assemblies provide a new theory of evoked potentials;
- the EEG frequencies are considered as a type of alphabet of brain function;
- based on the results described, brain oscillations are correlated with multiple functions, including sensory registration, perception, movement and cognitive processes related to attention,learning and memory;
- the superposition principle of event-related oscillations and brain Feynmann diagrams are introduced as metaphors from quantum theory.
Emotion decoding constitutes a case of multimodal processing of cues from multiple channels. Previous behavioural and neuropsychological studies indicated that, when we have to decode emotions on the basis of multiple perceptive information, a cross-modal integration has place. The present study investigates the simultaneous processing of emotional tone of voice and emotional facial expression by event-related potentials (ERPs), through an ample range of different emotions (happiness, sadness, fear, anger, surprise, and disgust). Auditory emotional stimuli (a neutral word pronounced in an affective tone) and visual patterns (emotional facial expressions) were matched in congruous (the same emotion in face and voice) and incongruous (different emotions) pairs. Subjects (N=30) were required to process the stimuli and to indicate their comprehension (by stimpad). ERPs variations and behavioural data (response time, RTs) were submitted to repeated measures analysis of variance (ANOVA). We considered two time intervals (150-250; 250-350 ms post-stimulus), in order to explore the ERP variations. ANOVA showed two different ERP effects, a negative deflection (N2), more anterior-distributed (Fz), and a positive deflection (P2), more posterior-distributed, with different cognitive functions. In the first case N2 may be considered a marker of the emotional content (sensitive to type of emotion), whereas P2 may represent a cross-modal integration marker, it being varied as a function of the congruous/incongruous condition, showing a higher peak for congruous stimuli than incongruous stimuli. Finally, a RT reduction was found for some emotion types for congruous condition (i.e. sadness) and an inverted effect for other emotions (i.e. fear, anger, and surprise).
Due to its fast temporal evolution and its representation and integration among complex and widespread neural networks, the emotion perception process should preferably be examined by means of multimethodological approach. Indeed the indubitable vantage of acquiring both the autonomic (arousal-related) and the central (cortical-related) activities stands in the possibility to better elucidate the reciprocal interplay of the two compartments. In the present study EEG (frequency band analysis), systemic SCR and heart rate (HR) were all recorded simultaneously with hemodynamic (NIRS, Near-Infrared Spectroscopy) measurements as potential biological markers of emotions, related to both central and peripheral systems. These multiple measures were then related to the self-report correlates, that is the subjective appraisal in term of valence (positive vs. negative) and arousal (high vs. low) by using SAM rating. Twenty subjects were submitted to emotional cues processing (IAPS) when fNIRS, frequency bands (alpha, beta, delta, theta), SCR and HR were recorded. As shown by O2Hb increasing within the right hemisphere, the contribution of prefrontal cortex was elucidated, by pointing out a relevant lateralization effect (more right-PFC activity) induced by the specific valence (negative) of the emotional patterns. Secondly, EEG activity (mainly low-frequency theta and delta bands) was intrinsically associated with the cortical hemodynamic responsiveness to the negative emotional patterns, within the right side. Finally SCR increased mainly in response to negative patterns, and the autonomic behavior was related to explicit (SAM) and cortical (NIRS; EEG) activity. The intrinsic relationships between these three different levels are discussed.
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The study investigates cross-modal simultaneous processing of emotional tone of voice and emotional facial expression by event-related potentials (ERPs), using a wide range of different emotions (happiness, sadness, fear, anger, surprise, and disgust). Auditory emotional stimuli (a neutral word pronounced in an affective tone) and visual patterns (emotional facial expressions) were matched in congruous (the same emotion in face and voice) and incongruous (different emotions) pairs. Subjects (N=31) were required to watch and listen to the stimuli in order to comprehend them. Repeated measures ANOVAs showed a positive ERP deflection (P2), more posterior distributed. This P2 effect may represent a marker of cross-modal integration, modulated as a function of congruous/incongruous condition. Indeed, it shows an ampler peak in response to congruous stimuli than incongruous ones. It is suggested P2 can be a cognitive marker of multisensory processing, independently from the emotional content.
presented an overview of recent research on anterior [cortical function] asymmetries associated with emotion and individual differences in emotional reactivity, psychopathologic states, dispositional mood, and temperament
sketch the major elements of the theoretical model that motivates the research to be presented / the methods that are common to our studies and the unique methodologic requirements of this research are then described / research on anterior asymmetries associated with the phasic arousal of emotion are presented, followed by a summary of our findings on the relations between individual differences in baseline asymmetry and affective reactivity (PsycINFO Database Record (c) 2012 APA, all rights reserved)
The present research firstly investigated the neural correlates (ERPs, event-related potentials) of attitudes to engage in prosocial-helping behaviors, and secondly, it analyzed the relation between these brain-based potentials and personal profile (high vs. low empathic profile). It was considered the subjects' behavior in response to specific emotional situations (positive vs. negative) in case it was required a possible prosocial intervention. Thirty-one subjects were invited to empathize with the emotional contexts (videotapes that reproduced two person's exchanges) and to decide whether to intervene or not to support these persons. BEES questionnaire for empathic behavior was submitted to the subjects after the experimental session. ERP acquisition and LORETA source analysis revealed a negative ongoing deflection (N200 effect) more prefrontally distributed (dorsolateral prefrontal cortex) in response to prosocial intervention options mainly for negative and positive contexts. Moreover, a significant positive correlation was found between high-empathic profiles, intervention behaviors (higher frequency of interventions) and N200 amplitude (higher peak). These results highlight the role of emotions in prosocial behavior, since the N200 effect was considered a marker of the emotional significance of the interpersonal situation. Secondly, the empathic trait may explain the prosocial decisional processes: Higher empathic trait contributes to induce subject's intervention behavior which in turn appears to be directly related to the cortical responsiveness within the prefrontal areas.
The present study integrated three different measures of emotional empathic behavior in a social context: verbal self-report measures (empathic response, emotional involvement, emotional significance, and valence), facial mimicry (activity of corrugator and zygomaticus muscles), and personal response to the Balanced Emotional Empathy Scale (BEES). Participants were presented with different interpersonal scene types (cooperation, noncooperation, conflict, indifference). Firstly, self-rating on empathy, emotional involvement, and valence varied as a function of interpersonal context. Secondly, corrugator activity increased in response to conflictual and noncooperative situations; zygomatic activity increased in response to cooperative situations. Third, high- and low-BEES subjects showed different empathic behavior: High-empathic subjects were more responsive to empathy-related situations than low-empathic subjects. The convergence and divergence of these multidimensional measures was discussed.
A suggestive hypothesis proposed that the lateral prefrontal cortex (LPFC) may be identified as the site of emotion-memory integration, since it was shown to be sensitive to the encoding and retrieval of emotional content. In the present research we explored the role of the dorsolateral prefrontal cortex (DLPFC) in memory retrieval of positive vs. negative emotional stimuli. This effect was analyzed by using an rTMS paradigm that induced a cortical activation of the left DLPFC. Subjects were required to perform a task consisting of two experimental phases: an encoding phase, where some lists composed by positive and negative emotional words were presented to the subjects; a retrieval phase, where the old stimuli and the new stimuli were presented for a recognition performance. The rTMS stimulation was provided during the retrieval phase over the left DLPFC. We found that the rTMS stimulation over this area affects the memory retrieval of positive emotional material, with higher memory efficiency (reduced RTs). This result suggested that left DLPFC activation promotes the memory retrieval of emotional information. Secondly, the valence model of emotional cue processing may explain decreasing of RTs, by pointing out the distinct role the left hemisphere has in positive emotional cue processing.
We discuss the application of beamforming techniques to the field of magnetoencephalography (MEG). We argue that beamformers have given us an insight into the dynamics of oscillatory changes across the cortex not explored previously with traditional analysis techniques that rely on averaged evoked responses. We review several experiments that have used beamformers, with special emphasis on those in which the results have been compared to those observed in functional magnetic resonance imaging (fMRI) and on those studying induced phenomena. We suggest that the success of the beamformer technique, despite the assumption that there are no linear interactions between the mesoscopic local field potentials across distinct cortical areas, may tell us something of the balance between functional integration and segregation in the human brain. What is more, MEG beamformer analysis facilitates the study of these complex interactions within cortical networks that are involved in both sensory-motor and cognitive processes. Hum. Brain Mapp 25:199–211, 2005. © 2005 Wiley-Liss, Inc.
We examine the effect of individual psychological differences on network structures, proposing several hypotheses about how individual differences might predispose actors to structure their social environment by seeking network closure or by sustaining structural holes. We introduce a new triad census method to examine personal networks of strong and weak ties. For 125 egocentric networks we correlated the triad census results with several extensively researched psychological instruments. The triad census reduced to three principal components, describing central aspects of strength-of-weak-ties and structural holes theories. Psychological predispositions explained a significant proportion of the variance in each of these components. Our results suggest that people who see themselves vulnerable to external forces tend to inhabit closed networks of weak connections. On the other hand, people who seek to keep their strong tie partners apart, and thereby bridge structural holes, tend to be individualists, to believe that they control the events in their lives, and to have higher levels of neuroticism. Finally, people with strong network closure and “weak” structural holes (as with the “strength of weak ties”) tend to categorize themselves and others in terms of group memberships. They also tend to be more extraverted and less individualistic.
Auditory event-related potentials mismatch negativity (MMN) and N100 were recorded from seven subjects while they read text and watched emotionally negative, neutral, and positive pictures varying in valence and arousal. The MMN reflects automatic detection of change in auditory stimulus stream. Functionally different N100 is triggered by onset of various auditory stimuli. The N100 was stabile during all visual conditions. The MMN was very similar during text reading, and neutral and negative slide viewing, but was significantly attenuated during viewing of positively valenced slides. We suggest that visual emotional information of high positive valence and low arousal is a signal of nonthreatening and nonappetitive environment. This kind of environment probably reduces the need for auditory change detection.
Alpha brain oscillation modulation was analyzed in response to masked emotional facial expressions. In addition, behavioural activation (BAS) and behavioural inhibition systems (BIS) were considered as an explicative factor to verify the effect of motivational significance on cortical activity. Nineteen subjects were submitted to an ample range of facial expressions of emotions (anger, fear, surprise, disgust, happiness, sadness, and neutral). The results demonstrated that anterior frontal sites were more active than central and posterior sites in response to facial stimuli. Moreover, right-side responses varied as a function of emotional types, with an increased right-frontal activity for negative emotions. Finally, whereas higher BIS subjects generated a more right hemisphere activation for some negative emotions (such as fear, anger, and surprise), Reward-BAS subjects were more responsive to positive emotion (happiness) within the left hemisphere. Valence and potential threatening power of facial expressions were considered to elucidate these cortical differences.
Empathy is related to the natural human ability to understand emotions and feelings of others, where a sort of "resonance" mechanism between the observer and the observed permits a direct form of understanding. The present study explored four different measures related to empathic behavior in a social context: autonomic behavior (skin conductance--SCR, and heart rate--HR), personal response to empathic scale (BEES), approach-withdrawal attitudes (BIS/BAS), and verbal self-report measures. Participants were presented with different interpersonal scene types (cooperation, non-cooperation, conflict, indifference), and they were required to empathize with them. Different autonomic response patterns were found as a function of the interpersonal situations: SCR and HR increased in case of conflictual and non-cooperative situations. This result was confirmed by self-rating measures on empathy, since emotional involvement and valence attributed to the scenes varied in concomitance with psychophysiological parameters. Third, high and low BEES subjects showed different empathic behavior: high empathic subjects were more responsive (on both self-report and autonomic response) to empathy-related situations than low empathic subjects. Finally, BIS and BAS attitudes demonstrated a significant relationship with both BEES and autonomic patterns: high BAS subjects were more responsive and empathic with positive, cooperative situations, whereas high BIS empathized with more negative, conflictual situations. The convergence of these multidimensional measures was discussed.
One important aspect of empathy is a "resonance mechanism", which includes emotional cue detection, facial mimicry (measured by electromyography, EMG) and a specific cortical response. This study explored the convergence of these three measures of affective empathy. The twenty students who took part in the study were required to empathise with the situation by entering into the other person's situation. The four emotions portrayed were anger, fear, happiness, and neutral, and the subjects were instructed to make a two-alternative response (emotion or no emotion) to each emotion. A repeated transcranial magnetic stimulation was used to produce a temporary inhibition of the medial prefrontal cortex (MPFC). The results support the hypothesis that there is a direct relationship between emotional cue recognition, EMG-measured facial response and prefrontal activity. First, both facial expression detection and autonomic mimicry in reaction to emotional faces were systematically modulated in response to inhibition of the MPFC. Second, the MPFC was implicated in facial cue detection and the subsequent autonomic response because an impaired performance on both measures was observed when this brain area was inhibited. Third, this effect increased when negative-valenced stimuli (angry and fearful faces) were presented to the subjects. These results revealed a significant effect of the MPFC on both cue detection and facial mimicry that was distinctly related to different types of emotions.
Empathic responses to facial cues are a main social competency. Both appraisal processes (facial emotion detection) and self-perceived empathy (empathic responsiveness) in response to emotional faces are thought to be related to empathic behavior, although no systematic analysis has been performed to assess their relationship.
The current research explored the contribution of the frontal sensorimotor system to facial detection and self-reported empathic measures by using repetitive transcranial magnetic stimulation (rTMS) to produce a temporary disruption of this specific cortical site.
Eighteen subjects were asked to detect facial expression of emotions (anger, fear, happiness, and neutrality) and to evaluate their empathic responsiveness to these facial cues. A 5-second rTMS (1 Hz, inhibition paradigm) pulse was delivered before the stimulus onset.
Error rates and response times (RTs) increased when brain activity was disrupted, specifically in response to anger and fear. Self-reported measures showed a concomitant decreased empathic response when the frontal sensorimotor system was deactivated.
The ability to monitor emotional cues and the behavioral empathic responsiveness to emotional situations was shown to be partially compromised in the case of frontal activity disruption, highlighting the main role of the sensorimotor system for empathic social skills.
Disruption of the sense of being effective and causally determinant in performing an action was explored in the present research by inducing an erroneous external spatial feedback in response to the subject's behaviour. ERPs were recorded from fifteen subjects when they were receiving mismatching/matching feedback information on direction. In addition, subjective sensitivity to the external cues was monitored by Behavioural Inhibition System (BIS) and Behavioural Activation System (BAS) measures, as well as Behaviour Identification process was tested by Behavior Identification Form (BIF). One negative ERP deflections of higher amplitude was revealed in concomitance to false feedback, peaking at about 210ms post-stimulus, more central-posteriorly localized. We supposed that it may represent feedback-error system of which activity might be reflected in FRN, deputed to monitor the unattended feedback furnished by an external system. Moreover, a P3b effect was also observed in great measure for false spatial feedback, more posteriorly (Pz) distributed. According to the context-updating hypothesis, the P3b may reflect the revision of the mental model of the context. BIS showed to be more sensitive to both veridical and false feedback that increased FRN, whereas higher-BAS and BAS-Reward measures revealed an increased proactive attitude to external feedback (higher P3b). Finally, low-level of action representation explained FRN amplitude more than high-level one.
The present study explored the effect of the subjective evaluation and the individual differences related to BIS and BAS (Behavioural Inhibition and Activation System) on autonomic measures and brain oscillations, in response to appetitive and aversive emotional stimuli. Multiple measures were recorded, such as psychophysiological (skin conductance response, heart rate, and electromyography) and frequency bands (delta, theta, alpha, and gamma), during viewing IAPS figures, that varied in terms of pleasantness (appetitive vs. aversive) and arousing power (high vs. low intensity). Both BIS and BAS measures were significant in modulating behavioural, autonomic and brain oscillations responses. Withdrawal (BIS system) and appetitive (BAS system) behaviour showed opposite patterns of responses by the subjects. Also, frontal cortical site response was more significant than other sites. Nevertheless, no specific lateralization effect was found as a function of BIS/BAS dichotomy. Moreover, autonomic variables and frequency band modulations were found to be effected by valence and arousal rating per se, with an increased response for high arousing and negative or positive stimuli in comparison with low arousing and neutral stimuli. The effects of subjective evaluation and individual differences were discussed at light of coping activity model of emotion comprehension.
The present study explored the effect of the individual differences related to BIS and BAS (Behavioural Inhibition and Activation System) on brain oscillations, in response to appetitive and aversive emotional stimuli. EEG cortical measures (delta, theta, alpha, and gamma) were recorded, during viewing IAPS figures, that varied in terms of pleasantness and arousal. Withdrawal (BIS system) and appetitive (BAS system) behaviour showed opposite patterns of subjective responses. Also, a specific frontal network was found to be responsive to the relevance of emotional cues. Moreover an increased response for high arousing (negative and positive) stimuli in comparison with low arousing and neutral stimuli was found within the left and right frontal areas. Specifically delta and theta band have a significant role in monitoring the attentional significance of emotions. Finally, the effects of subjective evaluation and individual differences were discussed at light of the two-dimensional model of emotion processing, that is the valence and the arousing power of emotional cues.
Asymmetry in comprehension of facial expression of emotions was explored in the present study by analysing alpha band variation within the right and left cortical sides. Second, the behavioural activation system (BAS) and behavioural inhibition system (BIS) were considered as an explicative factor to verify the effect of a motivational/emotional variable on alpha activity. A total of 19 participants looked at an ample range of facial expressions of emotions (anger, fear, surprise, disgust, happiness, sadness, and neutral) in random order. The results demonstrated that anterior frontal sites were more active than central and parietal sites in response to facial stimuli. Moreover, right and left side responses varied as a function of emotional types, with an increased right frontal activity for negative, aversive emotions vs an increased left response for positive emotion. Finally, whereas higher BIS participants generated more right hemisphere activation for some negative emotions (such as fear, anger, surprise, and disgust), BAS participants were more responsive to positive emotion (happiness) within the left hemisphere. Motivational significance of facial expressions was considered to elucidate cortical differences in participants' responses to emotional types.
The study aimed to explore the modulation of frequency bands (delta, theta, alpha-1 and alpha-2, and gamma) in response to emotional face within different post-stimulus time intervals (50-450 ms). Twenty adults looked at emotional (happy, sad, angry, fearful) or neutral faces. EEG results showed that motivational significance of face can modulate frequency bands, specifically for theta and gamma. Moreover, gamma can be varied related to degree of arousing feature (high or low) of facial expression. As a function of time, ANOVA and regression analysis revealed that emotional discrimination by gamma and theta is observable mainly within 150-250 time interval and, as revealed also by coherence analysis, that it is more distributed on the anterior-right (theta) or right (gamma) side of the scalp for the emotional stimuli, whereas delta is maximally increased within 250-350 interval and it is more posteriorly (parietal site) distributed for all the stimulus type. We proposed that band modulations respond to variations in processing emotional face, and, whereas delta reflects updating of the stimulus, and theta responds to the emotional significance of face, gamma reflects differences in the arousing power of facial expression.
The study aims to explore the significance of event-related potentials (ERPs) and event-related brain oscillations (EROs) (delta, theta, alpha, beta, gamma power) in response to emotional (fear, happiness, sadness) when compared with neutral faces during 180-250 post-stimulus time interval. The ERP results demonstrated that the emotional face elicited a negative peak at approximately 230 ms (N2). Moreover, EEG measures showed that motivational significance of face (emotional vs. neutral) could modulate the amplitude of EROs, but only for some frequency bands (i.e. theta and gamma bands). In a second phase, we considered the resemblance of the two EEG measures by a regression analysis. It revealed that theta and gamma oscillations mainly effect as oscillation activity at the N2 latency. Finally, a posterior increased power of theta was found for emotional faces.
The rapid detection of affective signals from conspecifics is crucial for the survival of humans and other animals; if those around you are scared, there is reason for you to be alert and to prepare for impending danger. Previous research has shown that the human brain detects emotional faces within 150 msec of exposure, indicating a rapid differentiation of visual social signals based on emotional content. Here we use event-related brain potential (ERP) measures to show for the first time that this mechanism extends to the auditory domain, using human nonverbal vocalizations, such as screams. An early fronto-central positivity to fearful vocalizations compared with spectrally rotated and thus acoustically matched versions of the same sounds started 150 msec after stimulus onset. This effect was also observed for other vocalized emotions (achievement and disgust), but not for affectively neutral vocalizations, and was linked to the perceived arousal of an emotion category. That the timing, polarity, and scalp distribution of this new ERP correlate are similar to ERP markers of emotional face processing suggests that common supramodal brain mechanisms may be involved in the rapid detection of affectively relevant visual and auditory signals.
Oscillations in the alpha and beta bands can display either an event-related blocking response or an event-related amplitude enhancement. The former is named event-related desynchronization (ERD) and the latter event-related synchronization (ERS). Examples of ERS are localized alpha enhancements in the awake state as well as sigma spindles in sleep and alpha or beta bursts in the comatose state. It was found that alpha band activity can be enhanced over the visual region during a motor task, or during a visual task over the sensorimotor region. This means ERD and ERS can be observed at nearly the same time; both form a spatiotemporal pattern, in which the localization of ERD characterizes cortical areas involved in task-relevant processing, and ERS marks cortical areas at rest or in an idling state.
We have reviewed the evidence that processes and functions related to perception and expression of emotions are represented asymmetrically in the cerebral hemispheres. The literature describes three possible aspects of emotional lateralization: that emotions are better recognized by the right hemisphere; that control of emotional expression and related behaviors takes place principally in the right hemisphere; and that the right hemisphere is specialized for dealing with negative emotions, while the left is specialized for dealing with positive emotions. Evidence for the three hypotheses derives from methodologically diverse studies in unimpaired, brain-lesioned, and mood-disordered populations. Relatively little of the work has been precisely replicated, and conclusions rest on parallel lines of evidence from diverse sources. The present level of knowledge suggests a model of emotional control based on interactive inhibition between a right negatively biased and left positively biased hemisphere. However, the details of such a model, including the precise conditions under which emotion-related functions are lateralized, and the mechanisms of such lateralization have yet to be elucidated.
The Self-Assessment Manikin (SAM) is a non-verbal pictorial assessment technique that directly measures the pleasure, arousal, and dominance associated with a person's affective reaction to a wide variety of stimuli. In this experiment, we compare reports of affective experience obtained using SAM, which requires only three simple judgments, to the Semantic Differential scale devised by Mehrabian and Russell (An approach to environmental psychology, 1974) which requires 18 different ratings. Subjective reports were measured to a series of pictures that varied in both affective valence and intensity. Correlations across the two rating methods were high both for reports of experienced pleasure and felt arousal. Differences obtained in the dominance dimension of the two instruments suggest that SAM may better track the personal response to an affective stimulus. SAM is an inexpensive, easy method for quickly assessing reports of affective response in many contexts.
This study is part of an effort to map neural systems involved in the processing of emotion, and it focuses on the possible cortical components of the process of recognizing facial expressions. We hypothesized that the cortical systems most responsible for the recognition of emotional facial expressions would draw on discrete regions of right higher-order sensory cortices and that the recognition of specific emotions would depend on partially distinct system subsets of such cortical regions. We tested these hypotheses using lesion analysis in 37 subjects with focal brain damage. Subjects were asked to recognize facial expressions of six basic emotions: happiness, surprise, fear, anger, disgust, and sadness. Data were analyzed with a novel technique, based on three-dimensional reconstruction of brain images, in which anatomical description of surface lesions and task performance scores were jointly mapped onto a standard brain-space. We found that all subjects recognized happy expressions normally but that some subjects were impaired in recognizing negative emotions, especially fear and sadness. The cortical surface regions that best correlated with impaired recognition of emotion were in the right inferior parietal cortex and in the right mesial anterior infracalcarine cortex. We did not find impairments in recognizing any emotion in subjects with lesions restricted to the left hemisphere. These data provide evidence for a neural system important to processing facial expressions of some emotions, involving discrete visual and somatosensory cortical sectors in right hemisphere.
In this article I discuss a hypothesis, known as the somatic marker hypothesis, which I believe is relevant to the understanding of processes of human reasoning and decision making. The ventromedial sector of the prefrontal cortices is critical to the operations postulated here, but the hypothesis does not necessarily apply to prefrontal cortex as a whole and should not be seen as an attempt to unify frontal lobe functions under a single mechanism. The key idea in the hypothesis is that 'marker' signals influence the processes of response to stimuli, at multiple levels of operation, some of which occur overtly (consciously, 'in mind') and some of which occur covertly (non-consciously, in a non-minded manner). The marker signals arise in bioregulatory processes, including those which express themselves in emotions and feelings, but are not necessarily confined to those alone. This is the reason why the markers are termed somatic: they relate to body-state structure and regulation even when they do not arise in the body proper but rather in the brain's representation of the body. Examples of the covert action of 'marker' signals are the undeliberated inhibition of a response learned previously; the introduction of a bias in the selection of an aversive or appetitive mode of behaviour, or in the otherwise deliberate evaluation of varied option-outcome scenarios. Examples of overt action include the conscious 'qualifying' of certain option-outcome scenarios as dangerous or advantageous. The hypothesis rejects attempts to limit human reasoning and decision making to mechanisms relying, in an exclusive and unrelated manner, on either conditioning alone or cognition alone.
A method for the calculation of significant changes in induced band power (IBP) is presented. In contrast to traditional measures of event-related band power (ERBP) which are composed of evoked and not evoked EEG components, the proposed measure for IBP is deprived from phase locked (or evoked) EEG activity. It is assumed that changes in IBP reflect the modulation of brain oscillations that are largely independent from ERPs. The results of a visual oddball task show that significant changes in IBP can be observed in response to the presentation of a warning signal (preceding a target or nontarget) and the imperative stimulus (i.e. a target or nontarget) in the alpha, theta and delta band. Only a few significant changes in IBP were obtained for the warning signal in the theta band although highly significant changes in ERBP were found. Our findings document that changes in IBP may be considered a phenomenon that is largely independent from the occurrence of ERPs. They underline the significance of oscillatory processes and suggest that induced rhythms are modulated by stimuli and/or events in a not phase locked way.
Two reports in the last issue of this journal attempted to replicate aspects of our previous studies on anterior electroencephalogram (EEG) asymmetry, affective style, and depression. In this commentary, an overview is provided of our model of anterior asymmetries, affective style, and psychopathology. Emphasis is placed on conceptualizing the prefrontal and anterior temporal activation patterns within a circuit that includes cortical and subcortical structures. The causal status of individual differences in asymmetric activation in the production of affective style and psychopathology is considered. Major emphasis is placed on EEG methods, particularly the need for multiple assessments to obtain estimates of asymmetric activation that better reflect an individual's true score. Issues specific to each of the two articles are also considered. Each of the articles has more consistency with our previously published data than the authors themselves suggest. Recommendations are made for future research to resolve some of the outstanding issues.
This study shows that incorrect responses are preceded by different EEG characteristics than correct responses, and that these differences appear in specific brain regions that participate in each particular task. EEGs were recorded in children during three different tasks: color discrimination (CDT), verbal working memory (VWM), and word categorization task (WCT). EEG segments previous to the presentation of the stimulus were analysed. Incorrect responses were preceded by lower EEG power values at 7.8 Hz in posterior temporal and right parietal leads in CDT, 8.59 and 9.36 Hz in frontal areas in VWM, and 10.72 Hz in the left hemisphere in WCT. In the former task > 1.56 Hz power in frontal areas prior to an incorrect response was also observed.
The question is examined whether the extent of changes in relative band power as measured by event-related desynchronization (ERD) depends on absolute band power. The results for target stimuli of a simple oddball task indicate that the prestimulus (reference) level of absolute band power has indeed a strong influence on ERD. Whereas for the alpha band large band power in the reference interval is related to a strong degree of alpha suppression as measured by ERD, the opposite holds true for the theta band. Here, a low level of band power during the reference interval is related to a pronounced increase in band power during the processing of the target stimulus. In contrast to alpha and theta, ERD in the delta band is not influenced by the magnitude of band power in the reference interval.
Prefrontal cortex provides both inhibitory and excitatory input to distributed neural circuits required to support performance in diverse tasks. Neurological patients with prefrontal damage are impaired in their ability to inhibit task-irrelevant information during behavioral tasks requiring performance over a delay. The observed enhancements of primary auditory and somatosensory cortical responses to task-irrelevant distractors suggest that prefrontal damage disrupts inhibitory modulation of inputs to primary sensory cortex, perhaps through abnormalities in a prefrontal-thalamic sensory gating system. Failure to suppress irrelevant sensory information results in increased neural noise, contributing to the deficits in decision making routinely observed in these patients. In addition to a critical role in inhibitory control of sensory flow to primary cortical regions, and tertiary prefrontal cortex also exerts excitatory input to activity in multiple sub-regions of secondary association cortex. Unilateral prefrontal damage results in multi-modal decreases in neural activity in posterior association cortex in the hemisphere ipsilateral to damage. This excitatory modulation is necessary to sustain neural activity during working memory. Thus, prefrontal cortex is able to sculpt behavior through parallel inhibitory and excitatory regulation of neural activity in distributed neural networks.