A neural link between affective understanding and interpersonal attraction.

Being able to comprehend another person's intentions and emotions is essential for successful social interaction. However, it is currently unknown whether the human brain possesses a neural mechanism that attracts people to others whose mental states they can easily understand. Here we show that the degree to which a person feels attracted to another person can change while they observe the other's affective behavior, and that these changes depend on the observer's confidence in having correctly understood the other's affective state. At the neural level, changes in interpersonal attraction were predicted by activity in the reward system of the observer's brain. Importantly, these effects were specific to individual observer-target pairs and could not be explained by a target's general attractiveness or expressivity. Furthermore, using multivoxel pattern analysis (MVPA), we found that neural activity in the reward system of the observer's brain varied as a function of how well the target's affective behavior matched the observer's neural representation of the underlying affective state: The greater the match, the larger the brain's intrinsic reward signal. Taken together, these findings provide evidence that reward-related neural activity during social encounters signals how well an individual's "neural vocabulary" is suited to infer another person's affective state, and that this intrinsic reward might be a source of changes in interpersonal attraction.

Social gating of sensory information during ongoing communication.

Social context plays an important role in human communication. Depending on the nature of the source, the same communication signal might be processed in fundamentally different ways. However, the selective modulation (or "gating") of the flow of neural information during communication is not fully understood. Here, we use multivoxel pattern analysis (MVPA) and multivoxel connectivity analysis (MVCA), a novel technique that allows to analyse context-dependent changes of the strength interregional coupling between ensembles of voxels, to examine how the human brain differentially gates content-specific sensory information during ongoing perception of communication signals. In a simulated electronic communication experiment, participants received two alternative text messages during fMRI ("happy" or "sad") which they believed had been sent either by their real-life friend outside the scanner or by a computer. A region in the dorsal medial prefrontal cortex (dmPFC) selectively increased its functional coupling with sensory-content encoding regions in the visual cortex when a text message was perceived as being sent by the participant's friend, and decreased its functional coupling with these regions when a text message was perceived as being sent by the computer. Furthermore, the strength of neural encoding of content-specific information of text messages in the dmPFC was modulated by the social tie between the participant and her friend: the more of her spare time a participant reported to spend with her friend the stronger was the neural encoding. This suggests that the human brain selectively gates sensory information into the relevant network for processing the mental states of others, depending on the source of the communication signal.

The Human Affectome.

Over the last decades, theoretical perspectives in the interdisciplinary field of the affective sciences have proliferated rather than converged due to differing assumptions about what human affective phenomena are and how they work. These metaphysical and mechanistic assumptions, shaped by academic context and values, have dictated affective constructs and operationalizations. However, an assumption about the purpose of affective phenomena can guide us to a common set of metaphysical and mechanistic assumptions. In this capstone paper, we home in on a nested teleological principle for human affective phenomena in order to synthesize metaphysical and mechanistic assumptions. Under this framework, human affective phenomena can collectively be considered algorithms that either adjust based on the human comfort zone (affective concerns) or monitor those adaptive processes (affective features). This teleologically-grounded framework offers a principled agenda and launchpad for both organizing existing perspectives and generating new ones. Ultimately, we hope the Human Affectome brings us a step closer to not only an integrated understanding of human affective phenomena, but an integrated field for affective research.

The support feature machine: classification with the least number of features and application to neuroimaging data.

By minimizing the zero-norm of the separating hyperplane, the support feature machine (SFM) finds the smallest subspace (the least number of features) of a data set such that within this subspace, two classes are linearly separable without error. This way, the dimensionality of the data is more efficiently reduced than with support vector-based feature selection, which can be shown both theoretically and empirically. In this letter, we first provide a new formulation of the previously introduced concept of the SFM. With this new formulation, classification of unbalanced and nonseparable data is straightforward, which allows using the SFM for feature selection and classification in a large variety of different scenarios. To illustrate how the SFM can be used to identify both the smallest subset of discriminative features and the total number of informative features in biological data sets we apply repetitive feature selection based on the SFM to a functional magnetic resonance imaging data set. We suggest that these capabilities qualify the SFM as a universal method for feature selection, especially for high-dimensional small-sample-size data sets that often occur in biological and medical applications.

Compensatory premotor activity during affective face processing in subclinical carriers of a single mutant Parkin allele.

Patients with Parkinson's disease suffer from significant motor impairments and accompanying cognitive and affective dysfunction due to progressive disturbances of basal ganglia-cortical gating loops. Parkinson's disease has a long presymptomatic stage, which indicates a substantial capacity of the human brain to compensate for dopaminergic nerve degeneration before clinical manifestation of the disease. Neuroimaging studies provide evidence that increased motor-related cortical activity can compensate for progressive dopaminergic nerve degeneration in carriers of a single mutant Parkin or PINK1 gene, who show a mild but significant reduction of dopamine metabolism in the basal ganglia in the complete absence of clinical motor signs. However, it is currently unknown whether similar compensatory mechanisms are effective in non-motor basal ganglia-cortical gating loops. Here, we ask whether asymptomatic Parkin mutation carriers show altered patterns of brain activity during processing of facial gestures, and whether this might compensate for latent facial emotion recognition deficits. Current theories in social neuroscience assume that execution and perception of facial gestures are linked by a special class of visuomotor neurons ('mirror neurons') in the ventrolateral premotor cortex/pars opercularis of the inferior frontal gyrus (Brodmann area 44/6). We hypothesized that asymptomatic Parkin mutation carriers would show increased activity in this area during processing of affective facial gestures, replicating the compensatory motor effects that have previously been observed in these individuals. Additionally, Parkin mutation carriers might show altered activity in other basal ganglia-cortical gating loops. Eight asymptomatic heterozygous Parkin mutation carriers and eight matched controls underwent functional magnetic resonance imaging and a subsequent facial emotion recognition task. As predicted, Parkin mutation carriers showed significantly stronger activity in the right ventrolateral premotor cortex during execution and perception of affective facial gestures than healthy controls. Furthermore, Parkin mutation carriers showed a slightly reduced ability to recognize facial emotions that was least severe in individuals who showed the strongest increase of ventrolateral premotor activity. In addition, Parkin mutation carriers showed a significantly weaker than normal increase of activity in the left lateral orbitofrontal cortex (inferior frontal gyrus pars orbitalis, Brodmann area 47), which was unrelated to facial emotion recognition ability. These findings are consistent with the hypothesis that compensatory activity in the ventrolateral premotor cortex during processing of affective facial gestures can reduce impairments in facial emotion recognition in subclinical Parkin mutation carriers. A breakdown of this compensatory mechanism might lead to the impairment of facial expressivity and facial emotion recognition observed in manifest Parkinson's disease.

Intentional social distance regulation alters affective responses towards victims of violence: an FMRI study.

We used functional magnetic resonance imaging (fMRI) to investigate brain processes underlying control of emotional responses towards a person in distress by cognitive social distance modulation. fMRI and peripheral physiological responses (startle response and electrodermal activity) were recorded from 24 women while they watched victim-offender scenes and modulated their social distance to the victim by cognitive reappraisal. We found that emotional responses, including startle eyeblink and amygdala responses, can effectively be modulated by social distance modulation. Furthermore, our data provide evidence that activity in the dorsomedial prefrontal cortex (dmPFC) and the anterior paracingulate cortex (aPCC), two brain regions that have previously been associated with brain processes related to distant and close others, is differentially modulated by intentional social distance modulation: activity in the dmPFC increased with increasing disengagement from the victim and activity in the aPCC increased with increasing engagement with the victim. We suggest that these two regions play opposing roles in cognitive modulation of social distance and affective responses towards persons in distress that enable the adaptive and flexible social behavior observed in humans.

Emotional responses in spider fear are closely related to picture awareness.

Theories of emotion propose that responses to emotional pictures can occur independently of whether or not people are aware of the picture content. Because evidence from dissociation paradigms is inconclusive, we manipulated picture awareness gradually and studied whether emotional responses varied with degree of awareness. Spider fearful and non-fearful participants viewed pictures of spiders and flowers at four levels of backward masking while electrodermal activity and heart rate were measured continuously. Recognition ratings confirmed that participants' picture awareness decreased with masking. Critically, effects of spider fear on emotion ratings and heart rate also decreased with masking. These findings suggest that effects of spider fear on emotion ratings and heart rate are closely related to picture awareness.

Surgical face masks do not impair the decoding of facial expressions of negative affect more severely in older than in younger adults.

Surgical face masks reduce the spread of airborne pathogens but also disturb the flow of information between individuals. The risk of getting seriously ill after infection with SARS-COV-2 during the present COVID-19 pandemic amplifies with age, suggesting that face masks should be worn especially during face-to-face contact with and between older people. However, the ability to accurately perceive and understand communication signals decreases with age, and it is currently unknown whether face masks impair facial communication more severely in older people. We compared the impact of surgical face masks on dynamic facial emotion recognition in younger (18-30 years) and older (65-85 years) adults (N = 96) in an online study. Participants watched short video clips of young women who facially expressed anger, fear, contempt or sadness. Faces of half of the women were covered by a digitally added surgical face mask. As expected, emotion recognition accuracy declined with age, and face masks reduced emotion recognition accuracy in both younger and older participants. Unexpectedly, the effect of face masks did not differ between age groups. Further analyses showed that masks also reduced the participants' overall confidence in their emotion judgements, but not their performance awareness (the difference between their confidence ratings for correct and incorrect responses). Again, there were no mask-by-age interactions. Finally, data obtained with a newly developed questionnaire (attitudes towards face masks, atom) suggest that younger and older people do not differ in how much they feel impaired in their understanding of other people's emotions by face masks or how useful they find face masks in confining the COVID-19 pandemic. In sum, these findings do not provide evidence that the impact of face masks on the decoding of facial signals is disproportionally larger in older people.

Flow of affective information between communicating brains.

When people interact, affective information is transmitted between their brains. Modern imaging techniques permit to investigate the dynamics of this brain-to-brain transfer of information. Here, we used information-based functional magnetic resonance imaging (fMRI) to investigate the flow of affective information between the brains of senders and perceivers engaged in ongoing facial communication of affect. We found that the level of neural activity within a distributed network of the perceiver's brain can be successfully predicted from the neural activity in the same network in the sender's brain, depending on the affect that is currently being communicated. Furthermore, there was a temporal succession in the flow of affective information from the sender's brain to the perceiver's brain, with information in the perceiver's brain being significantly delayed relative to information in the sender's brain. This delay decreased over time, possibly reflecting some 'tuning in' of the perceiver with the sender. Our data support current theories of intersubjectivity by providing direct evidence that during ongoing facial communication a 'shared space' of affect is successively built up between senders and perceivers of affective facial signals.

Task-specific activity and connectivity within the mentalizing network during emotion and intention mentalizing.

Mentalizing, i.e. the process of inferring another person's mental state, is thought to be primarily subserved by three brain regions, the VMPFC (ventromedial prefrontal cortex), precuneus and TPJ (temporo-parietal junction). However, it is still unclear what the exact roles of these regions in mentalizing are. Here, we compare activity within, and functional connectivity between, the VMPFC, precuneus and TPJ during two different mentalizing tasks. Specifically, we examine whether inferring another person's emotion ("emotion mentalizing") and inferring another person's intention ("intention mentalizing") activate similar or distinct subregions within the VMPFC, precuneus and TPJ, and whether these different kinds of mentalizing are associated with different patterns of functional connectivity between these regions. Our results indicate that emotion mentalizing and intention mentalizing activate partly distinct subregions of the right and left TPJ that can be spatially separated across participants. These subregions also showed different patterns of functional connectivity with the VMPFC: a more anterior region of the right and left TPJ, which was more strongly activated during emotion mentalizing, showed stronger functional connectivity with the VMPFC, particularly during emotion mentalizing, than a more posterior region that was more strongly activated during intention mentalizing. Critically, this double dissociation became evident only when the fine-scale distribution of activity within activated regions was analysed, and despite the fact that there was also a significant overlap of activity during the two tasks. Our findings provide first evidence that different neural modules might have evolved within the TPJ that show distinct patterns of functional connectivity and might subserve slightly different subfunctions of mentalizing.

The neuroscience of social feelings: mechanisms of adaptive social functioning.

Social feelings have conceptual and empirical connections with affect and emotion. In this review, we discuss how they relate to cognition, emotion, behavior and well-being. We examine the functional neuroanatomy and neurobiology of social feelings and their role in adaptive social functioning. Existing neuroscience literature is reviewed to identify concepts, methods and challenges that might be addressed by social feelings research. Specific topic areas highlight the influence and modulation of social feelings on interpersonal affiliation, parent-child attachments, moral sentiments, interpersonal stressors, and emotional communication. Brain regions involved in social feelings were confirmed by meta-analysis using the Neurosynth platform for large-scale, automated synthesis of functional magnetic resonance imaging data. Words that relate specifically to social feelings were identfied as potential research variables. Topical inquiries into social media behaviors, loneliness, trauma, and social sensitivity, especially with recent physical distancing for guarding public and personal health, underscored the increasing importance of social feelings for affective and second person neuroscience research with implications for brain development, physical and mental health, and lifelong adaptive functioning.

When seeing outweighs feeling: a role for prefrontal cortex in passive control of negative affect in blindsight.

Affective neuroscience has been strongly influenced by the view that a 'feeling' is the perception of somatic changes and has consequently often neglected the neural mechanisms that underlie the integration of somatic and other information in affective experience. Here, we investigate affective processing by means of functional magnetic resonance imaging in nine cortically blind patients. In these patients, unilateral postgeniculate lesions prevent primary cortical visual processing in part of the visual field which, as a result, becomes subjectively blind. Residual subcortical processing of visual information, however, is assumed to occur in the entire visual field. As we have reported earlier, these patients show significant startle reflex potentiation when a threat-related visual stimulus is shown in their blind visual field. Critically, this was associated with an increase of brain activity in somatosensory-related areas, and an increase in experienced negative affect. Here, we investigated the patients' response when the visual stimulus was shown in the sighted visual field, that is, when it was visible and cortically processed. Despite the fact that startle reflex potentiation was similar in the blind and sighted visual field, patients reported significantly less negative affect during stimulation of the sighted visual field. In other words, when the visual stimulus was visible and received full cortical processing, the patients' phenomenal experience of affect did not closely reflect somatic changes. This decoupling of phenomenal affective experience and somatic changes was associated with an increase of activity in the left ventrolateral prefrontal cortex and a decrease of affect-related somatosensory activity. Moreover, patients who showed stronger left ventrolateral prefrontal cortex activity tended to show a stronger decrease of affect-related somatosensory activity. Our findings show that similar affective somatic changes can be associated with different phenomenal experiences of affect, depending on the depth of cortical processing. They are in line with a model in which the left ventrolateral prefrontal cortex is a relay station that integrates information about subcortically triggered somatic responses and information resulting from in-depth cortical stimulus processing. Tentatively, we suggest that the observed decoupling of somatic responses and experienced affect, and the reduction of negative phenomenal experience, can be explained by a left ventrolateral prefrontal cortex-mediated inhibition of affect-related somatosensory activity.

Empathic responses to unknown others are modulated by shared behavioural traits.

How empathically people respond to a stranger's pain or pleasure does not only depend on the situational context, individual traits and intentions, but also on interindividual factors. Here we ask whether empathic responses towards unknown others are modulated by behavioural similarity as a potential marker of genetic relatedness. Participants watched two supposed human players who were modelled as having a strong (player LP) or weak (player NLP) tendency to lead in social situations executing penalty shots in a virtual reality robot soccer game. As predicted, empathic response were modulated by shared behavioural traits: participants whose tendency to lead was more similar to player LP's tendency to lead experienced more reward, and showed stronger neural activity in reward-related brain regions, when they saw player LP score a goal, and participants whose tendency to lead was more similar to player NLP's tendency to lead showed stronger empathic responses when they saw player NLP score a goal. These findings highlight the potentially evolutionary grounded role of phenotypic similarity for neural processes underlying human social perception.

Pseudo-hyperscanning shows common neural activity during face-to-face communication of affect to be associated with shared affective feelings but not with mere emotion recognition.

Current theories in cognitive neuroscience assume that internal simulation, i.e., the reproduction of brain activity underlying another person's inner state and behaviour in the perceiver's brain, plays an important role in understanding others. Here we test the prediction that common neural activity during facial communication of affect leads to interpersonal understanding. Six female senders and 30 male observers (six of which were the senders romantic partners and 24 unknown others) underwent pseudo-hyperscanning fMRI (functional magnetic resonance imaging). Senders were asked to submerge themselves into emotional situations and to facially express their emotional feelings as they arose to the observer. Observers were uninformed about the sender's task and were asked to watch and feel with the sender. Using between-brain spatial correlation analysis we found that mere emotion recognition was not closely related to the degree to which an observer reproduced the sender's spatial pattern of neural activity in his own brain. However, in runs in which the observer had correctly identified the communicated emotion, between-brain similarity of spatial patterns of neural activity predicted the degree to which the observer experienced a similar emotional feeling as the sender. This effect remained significant when differences between romantic partners and unknown others and sender effects were removed. These findings are in line with previous studies that suggest that facial emotion recognition, at least at a coarse level, might be supported by neural processes that do not rely on internal simulation. Shared affective experiences, on the other hand, might arise from common neural activity between the sender's and the observer's brain, leading to a "shared space of affect" which might be critical for the flow of more subtle affective information between brains.

Sleep deprivation selectively enhances interpersonal emotion recognition from dynamic facial expressions at long viewing times: An observational study.

Observational and experimental studies have shown that sleep deprivation disinhibits emotional responses to disturbing and rewarding external events. On the other hand, most studies on sleep deprivation and interpersonal emotion recognition report that sensitivity to others' emotions is dampened during sleep deprivation. This is at odds with current neuroscientific theories of social cognition that assume that affective experiences and emotion recognition in others are closely tied at the neural and physiological level. In this observational study we show that sleep deprivation can actually increase emotion recognition accuracy from dynamically unfolding facial expressions if they are viewed sufficiently long. Participants viewed 2-4 s or 8-10s video clips of female senders who facially communicated anger, disgust, fear or sadness to their romantic partner and evaluated the sender's affective state in a forced-choice paradigm, either during sleep deprivation after a night shift (N = 40) or after normal night sleep (N = 50). All participants showed a significant increase in emotion recognition accuracy from 2-4 s to 8-10 s stimulus presentation times. Emotion recognition accuracy did not differ between sleep-deprived and control participants for 2-4 s videos, but sleep-deprived participants showed significantly higher emotion recognition accuracy than control participants for 8-10 s videos. We surmise that this effect might be due to the break-down of prefrontal activity associated with sleep deprivation, which might not only disinhibit affective responses to external events but might also release simulation-based neural processes that contribute to interpersonal emotion recognition from dynamic facial expressions at longer time scales than usually investigated in emotion recognition studies.

Parietal somatosensory association cortex mediates affective blindsight.

To investigate the neural substrates underlying emotional feelings in the absence of a conscious stimulus percept, we presented a visual stimulus in the blind field of partially cortically blind patients and measured cortical activity (by functional magnetic resonance imaging, fMRI) before and after the stimulus had been paired with an aversive event. After pairing, self-reported negative emotional valence and blood oxygen level-dependent (BOLD) responses in somatosensory association areas were enhanced, whereby somatosensory activity predicted highly corresponding reported feelings and startle reflex amplitudes across subjects. Our data provide direct evidence that cortical activity representing physical emotional states governs emotional feelings.

Brain responses to emotional stimuli in patients with amyotrophic lateral sclerosis (ALS).

Amyotrophic lateral sclerosis (ALS), a progressive motor neuron disease, affects movement and communication abilities and emotional processing. Subjective ratings of emotional stimuli depicting social interactions and facial expressions differed significantly between ALS patients and healthy controls in a previous study with a reduction of negative emotional valence (pleasantness) and lower subjective arousal (excitement) in ALS patients. In the present study, sixty similar emotional slides were presented to 13 ALS patients, 15 matched healthy controls and six tetraplegic patients. Subjective reports of valence and arousal as well as brain responses to the affective pictures using functional magnetic resonance imaging (fMRI) were measured. The picture series was presented twice with a 6-months interval to investigate effects of disease progression. ALS patients presented an increased brain response in the right supramarginal area and a reduced brain response in extrastriate visual areas at both measurements compared with healthy controls. Within the ALS patients' group a reduction of brain responses in the anterior insula at the follow-up was correlated with the subjective arousal. The reduced response in the anterior insula is tentatively interpreted as indicating reduced arousal during the course of the disease at the neural and behavioural level. The reduction of activity in extrastriate visual areas might be similarly interpreted. The increased brain response in the right supramarginal area of ALS patients might represent an altered sensitivity to social-emotional cues.

Impaired Emotional Mirroring in Parkinson's Disease-A Study on Brain Activation during Processing of Facial Expressions.

BACKGROUND: Affective dysfunctions are common in patients with Parkinson's disease, but the underlying neurobiological deviations have rarely been examined. Parkinson's disease is characterized by a loss of dopamine neurons in the substantia nigra resulting in impairment of motor and non-motor basal ganglia-cortical loops. Concerning emotional deficits, some studies provide evidence for altered brain processing in limbic- and lateral-orbitofrontal gating loops. In a second line of evidence, human premotor and inferior parietal homologs of mirror neuron areas were involved in processing and understanding of emotional facial expressions. We examined deviations in brain activation during processing of facial expressions in patients and related these to emotion recognition accuracy. METHODS: 13 patients and 13 healthy controls underwent an emotion recognition task and a functional magnetic resonance imaging (fMRI) measurement. In the Emotion Hexagon test, participants were presented with blends of two emotions and had to indicate which emotion best described the presented picture. Blended pictures with three levels of difficulty were included. During fMRI scanning, participants observed video clips depicting emotional, non-emotional, and neutral facial expressions or were asked to produce these facial expressions themselves. RESULTS: Patients performed slightly worse in the emotion recognition task, but only when judging the most ambiguous facial expressions. Both groups activated inferior frontal and anterior inferior parietal homologs of mirror neuron areas during observation and execution of the emotional facial expressions. During observation, responses in the pars opercularis of the right inferior frontal gyrus, in the bilateral inferior parietal lobule and in the bilateral supplementary motor cortex were decreased in patients. Furthermore, in patients, activation of the right anterior inferior parietal lobule was positively related to accuracy in the emotion recognition task. CONCLUSION: Our data provide evidence for a contribution of human homologs of monkey mirror areas to the emotion recognition deficit in Parkinson's disease.

The multiple facets of empathy: a survey of theory and evidence.

Empathy is the ability to perceive and understand other people's emotions and to react appropriately. This ability is a necessary prerequisite for successful interpersonal interaction. Empathy is a multifaceted construct including low-level mechanisms like emotional contagion as well as high-level processes like perspective-taking. The ability to empathize varies between individuals and is considered a stable personality trait: some people are generally more successful in empathizing than others. In this chapter we will first present different conceptualizations of the construct of empathy, and refer to empathy-regulating processes as well as to the relationship between empathy and social behavior. Then, we will review peripheral physiological and brain imaging studies pertaining to low- and high-level empathic processes, empathy-modulating processes, and the link between empathy and social behavior. Further, we will present evidence regarding interindividual differences in these processes as an important source of information for solving the conundrum of how the comprehension of others' emotions is achieved by our brains.

Effects of prosodic emotional intensity on activation of associative auditory cortex.

Functional magnetic resonance imaging was used to investigate hemodynamic responses to adjectives pronounced in happy and angry intonations of varying emotional intensity. In separate sessions, participants judged the emotional valence of either intonation or semantics. To disentangle effects of emotional prosodic intensity from confounding acoustic parameters, mean and variability of volume and fundamental frequency of each stimulus were included as nuisance variables in the statistical models. A linear dependency between hemodynamic responses and emotional intensity of happy and angry intonations was found in the bilateral superior temporal sulcus during both tasks, indicating that increases of hemodynamic responses in this region are elicited by both positive and negative prosody independent of low-level acoustic properties and task instructions.