His or mine? The time course of self–other discrimination in emotion processing

This electroencephalography (EEG) study investigated at which temporal processing stages self–other discrimination in emotion processing occurs. EEG was recorded in 23 healthy participants during silent reading of unpleasant, pleasant, and neutral pronoun–noun and article–noun expressions that were related to the participants themselves, related to an unknown third person, or had no self–other reference at all. Self- and other-related pronoun–noun pairs elicited larger cortical negativity relative to the processing of article–noun pairs at left posterior electrodes as early as 200 ms after stimulus onset. In the same time windows (from 200 ms to 300 ms and 300 ms to 400 ms) the emotionality of the words enhanced event-related brain potential (ERP) amplitudes at parieto-occipital electrodes. From 350 ms onwards, processing of self-related unpleasant words elicited larger frontal negativity compared to unpleasant words that were related to the other or that had no reference at all. In addition, processing of pleasant words vs. neutral or unpleasant words elicited larger positive amplitudes over parietal electrodes from 450 ms after stimulus onset, in particular when words were self-related. Our findings demonstrate that for verbal emotional stimuli, self–other discrimination first occurs at higher-order, cortical processing stages. This is consistent with the view that categorization of information according to certain stimulus aspects (self–other reference, emotionality) occurs before its meaning is integrated.     

His or mine? The time course of self-other discrimination in emotion processing

This electroencephalography (EEG) study investigated at which temporal processing stages self-other discrimination in emotion processing occurs. EEG was recorded in 23 healthy participants during silent reading of unpleasant, pleasant, and neutral pronoun-noun and article--noun expressions that were related to the participants themselves, related to an unknown third person, or had no self-other reference at all. Self- and other-related pronoun--noun pairs elicited larger cortical negativity relative to the processing of article--noun pairs at left posterior electrodes as early as 200 ms after stimulus onset. In the same time windows (from 200 ms to 300 ms and 300 ms to 400 ms) the emotionality of the words enhanced event-related brain potential (ERP) amplitudes at parieto-occipital electrodes. From 350 ms onwards, processing of self-related unpleasant words elicited larger frontal negativity compared to unpleasant words that were related to the other or that had no reference at all. In addition, processing of pleasant words vs. neutral or unpleasant words elicited larger positive amplitudes over parietal electrodes from 450 ms after stimulus onset, in particular when words were self-related. Our findings demonstrate that for verbal emotional stimuli, self--other discrimination first occurs at higher-order, cortical processing stages. This is consistent with the view that categorization of information according to certain stimulus aspects (self--other reference, emotionality) occurs before its meaning is integrated.     

Cognitive behavioral therapy for depression changes medial prefrontal and ventral anterior cingulate cortex activity associated with self-referential processing

Cognitive behavioral therapy (CBT), an effective treatment for depression, targets self-referential processing of emotional stimuli. We examined the effects of CBT on brain functioning during self-referential processing in depressive patients using functional magnetic resonance imaging (fMRI). Depressive patients (n = 23) and healthy participants (n = 15) underwent fMRI scans during a self-referential task using emotional trait words. The depressive patients had fMRI scans before and after completing a total of 12 weekly sessions of group CBT for depression, whereas the healthy participants underwent fMRI scans 12 weeks apart with no intervention. Before undergoing CBT, the depressive patients showed hyperactivity in the medial prefrontal cortex (MPFC) during self-referential processing of negative words. Following CBT, MPFC and ventral anterior cingulate cortex (vACC) activity during self-referential processing among depressive patients was increased for positive stimuli, whereas it was decreased for negative stimuli. Improvements in depressive symptoms were negatively correlated with vACC activity during self-referential processing of negative stimuli. These results suggest that CBT-related improvements in depressive symptoms are associated with changes in MPFC and vACC activation during self-referential processing of emotional stimuli.     

Negative content enhances stimulus‐specific cerebral activity during free viewing of pictures,faces, and words

Negative visual stimuli have been found to elicit stronger brain activation than do neutral stimuli. Such emotion effects have been shown for pictures, faces, and words alike, but the literature suggests stimulus‐specific differences regarding locus and lateralization of the activity. In the current functional magnetic resonance imaging study, we directly compared brain responses to passively viewed negative and neutral pictures of complex scenes, faces, and words (nouns) in 43 healthy participants (21 males) varying in age and demographic background. Both negative pictures and faces activated the extrastriate visual cortices of both hemispheres more strongly than neutral ones, but effects were larger and extended more dorsally for pictures, whereas negative faces additionally activated the superior temporal sulci. Negative words differentially activated typical higher‐level language processing areas such as the left inferior frontal and angular gyrus. There were small emotion effects in the amygdala for faces and words, which were both lateralized to the left hemisphere. Although pictures elicited overall the strongest amygdala activity, amygdala response to negative pictures was not significantly stronger than to neutral ones. Across stimulus types, emotion effects converged in the left anterior insula. No gender effects were apparent, but age had a small, stimulus‐specific impact on emotion processing. Our study specifies similarities and differences in effects of negative emotional content on the processing of different types of stimuli, indicating that brain response to negative stimuli is specifically enhanced in areas involved in processing of the respective stimulus type in general and converges across stimuli in the left anterior insula.     

Increased amygdala and insula activation during emotion processing in anxiety-prone subjects

OBJECTIVE: Increased amygdala reactivity during processing of certain types of emotional stimuli (e.g., fear, anger) has been observed in patients with anxiety disorders such as social phobia and posttraumatic stress disorder (PTSD). It is uncertain whether this heightened amygdala reactivity is specific to treatment-seeking patients with anxiety disorders or is a general feature of individuals with increased anxiety-related temperamental traits. METHOD: Thirty-two physically healthy subjects 18-21 years old were recruited from a large pool of college students. Of these, 16 were chosen on the basis of scoring in the upper-15th percentile on a measure of trait anxiety (anxiety-prone group), and 16 were chosen on the basis of scoring in the normative range (40th-60th percentile). Subjects participated in functional magnetic resonance imaging (fMRI) during an emotion face assessment task that has been shown to reliably engage amygdala and associated limbic structures. RESULTS: Anxiety-prone subjects had significantly greater bilateral amygdala and insula activation to emotional faces than did the anxiety-normative comparison subjects. Higher scores on several measures assessing anxiety proneness (e.g., neuroticism, trait anxiety, and anxiety sensitivity) were associated with greater activation of the amygdala (predominantly left-sided) and the anterior insula (bilateral). CONCLUSIONS: Increased amygdala and insula reactivity to certain types of emotional processing is seen in young adults with increased anxiety-related temperamental traits. Therefore, this brain emotion-processing profile may be a functional endophenotype for proneness to (certain kinds of) anxiety disorders.     

Towards a functional neuroanatomy of self processing: effects of faces and words

We studied the neural correlates of self vs. non-self judgements using functional magnetic resonance imaging (fMRI). Individually tailored faces and personality trait words were used as stimuli in three experiments (exp.). In the first two experiments, brain activation was measured while subjects viewed morphed versions of either their own (self face exp.) or their partner's face (partner's face exp.), alternating in blocks with presentation of an unknown face. In the self face exp. right limbic areas (hippocampal formation, insula, anterior cingulate), the right middle temporal lobe, left inferior parietal and left prefrontal regions showed signal changes. In the partner's face exp., only the right insula was activated. In the third exp., subjects made decisions about psychological trait adjectives previously categorized as describing their own attributes. Activation was present in the precuneus, the left parietal lobe, left insula/inferior frontal gyrus and the left anterior cingulate. A reaction time advantage was present when subjects responded to self-relevant words. The main area with signal changes during self-reference processing, regardless of the type of stimulus, was the left fusiform gyrus. The self-relevant stimuli engaged to a differential extent long term and working memory, semantic and emotional processes. We suggest that regions activated by these stimuli are engaged in self-processing.     

Brain activation during direct and indirect processing of positive and negative words

The effects of task conditions on brain activation to emotional stimuli are poorly understood. In this event-related fMRI study, brain activation to negative and positive words (matched for arousal) and neutral words was investigated under two task conditions. Subjects either had to attend to the emotional meaning (direct task) or to non-emotional features of the words (indirect task). Regardless of task, positive vs. negative words led to increased activation in the ventral medial prefrontal cortex, while negative vs. positive words induced increased activation of the insula. Compared to neutral words, all emotional words were associated with increased activation of the amygdala. Finally, the direct condition, as compared to the indirect condition, led to enhanced activation to emotional vs. neutral words in the dorsomedial prefrontal cortex and the anterior cingulate cortex. These results suggest valence and arousal dependent brain activation patterns that are partially modulated by participants’ processing mode of the emotional stimuli.     

Exaggerated affect-modulated startle during unpleasant stimuli in borderline personality disorder.

BACKGROUND: Excessive emotional responding is considered to be a hallmark of borderline personality disorder (BPD). The affect-modulated startle response is a reliable indicator of emotional processing of stimuli. The aim of this study was to examine emotional processing in BPD patients (n = 27) and healthy control subjects (n = 21). METHODS: Participants viewed an intermixed series of unpleasant, borderline-salient (e.g., "hate"), and neutral (e.g., "view") words and were instructed to think about the meaning of the word for them personally while eyeblink responses were assessed. RESULTS: The BPD patients exhibited larger startle eyeblink during unpleasant but not neutral words, indicating exaggerated physiological affect. This finding remained significant when we controlled for comorbid diagnoses, including generalized anxiety disorder and post-traumatic stress disorder. Greater symptom severity was associated with greater affective-startle difference scores (unpleasant-neutral). CONCLUSIONS: Consistent with the symptom of affective dysregulation, these results suggest an abnormality in the processing of unpleasant emotional stimuli by BPD patients.     

Activation of the medial prefrontal cortex and extended amygdala by individual ratings of emotional arousal: a fMRI study.

BACKGROUND: Significant differences between individual responses to emotional stimuli can be important for the study of emotion. We investigated whether incorporating individual ratings of emotional arousal in the analysis of functional magnetic resonance imaging (fMRI) data improves the detection of activation in the medial prefrontal cortex (MPFC) and sublenticular extended amygdala (SLEA), areas implicated in the processing of emotional salience. METHODS: Healthy subjects viewed counterbalanced blocks of aversive, nonaversive, and blank images. Outside the scanner, they rated the intensity of emotional arousal (salience) of each presented picture. RESULTS: Incorporating the subject's response to each stimulus by using individualized regressors produced more robust activations within MPFC and SLEA compared with a simple boxcar regressor, identical for all subjects. CONCLUSIONS: Our findings demonstrate that individual behavioral data are useful in improving detection of activation in block-design functional imaging studies.     

Posterior cingulate cortex activation by emotional words: fMRI evidence from a valence decision task

Functional imaging studies consistently find that emotional stimuli activate the posterior cingulate cortex, a region that appears to have memory-related functions. However, prior imaging studies have not controlled for non-emotional stimulus features that might activate this region by engaging memory processes unrelated to emotion. This study examined whether emotional words activated the posterior cingulate cortex when these potentially confounding factors were controlled. Sixty-four pleasant and 64 unpleasant words were matched with neutral words on non-emotional features known to influence memory. Eight subjects underwent block-designed functional magnetic resonance imaging scans while evaluating the valence of these words. The posterior cingulate cortex was significantly activated bilaterally during both unpleasant and pleasant compared to neutral words. The strongest activation peak with both unpleasant and pleasant words was observed in the left subgenual cingulate cortex. Anteromedial orbital and left inferior and middle frontal cortices were also activated by both pleasant and unpleasant words. Right amygdala and auditory cortex were activated only by unpleasant words, while left frontal pole was activated only by pleasant words. The results show that activation of the posterior cingulate cortex by emotional stimuli cannot be attributed to the memory-enhancing effects of non-emotional stimulus features. The findings are consistent with the suggestion that this region may mediate interactions of emotional and memory-related processes. The results also extend prior findings that evaluating emotional words consistently activates the subgenual cingulate cortex, and suggest a means of probing this region in patients with mood disorders.     

Distinct regions of the medial prefrontal cortex are associated with self-referential processing and perspective taking

The medial prefrontal cortex (MPFC) appears to play a prominent role in two fundamental aspects of social cognition, that is, self-referential processing and perspective taking. However, it is currently unclear whether the same or different regions of the MPFC mediate these two interdependent processes. This functional magnetic resonance imaging study sought to clarify the issue by manipulating both dimensions in a factorial design. Participants judged the extent to which trait adjectives described their own personality (e.g., "Are you sociable?") or the personality of a close friend (e.g., "Is Caroline sociable?") and were also asked to put themselves in the place of their friend (i.e., to take a third-person perspective) and estimate how this person would judge the adjectives, with the target of the judgments again being either the self (e.g., "According to Caroline, are you sociable?") or the other person (e.g., "According to Caroline, is she sociable?"). We found that self-referential processing (i.e., judgments targeting the self vs. the other person) yielded activation in the ventral and dorsal anterior MPFC, whereas perspective taking (i.e., adopting the other person's perspective, rather than one's own, when making judgments) resulted in activation in the posterior dorsal MPFC; the interaction between the two dimensions yielded activation in the left dorsal MPFC. These findings show that self-referential processing and perspective taking recruit distinct regions of the MPFC and suggest that the left dorsal MPFC may be involved in decoupling one's own from other people's perspectives on the self.     

The role of the amygdala in human fear: automatic detection of threat

Behavioral data suggest that fear stimuli automatically activate fear and capture attention. This effect is likely to be mediated by a subcortical brain network centered on the amygdala. Consistent with this view, brain imaging studies show that masked facial stimuli activate the amygdala as do masked pictures of threatening animals such as snakes and spiders. When the stimulus conditions allow conscious processing, the amygdala response to feared stimuli is enhanced and a cortical network that includes the anterior cingulate cortex and the anterior insula is activated. However, the initial amygdala response to a fear-relevant but non-feared stimulus (e.g. pictures of spiders for a snake phobic) disappears with conscious processing and the cortical network is not recruited. Instead there is activation of the dorsolateral and orbitofrontal cortices that appears to inhibit the amygdala response. The data suggest that activation of the amygdala is mediated by a subcortical pathway, which passes through the superior colliculi and the pulvinar nucleus of the thalamus before accessing the amygdala, and which operates on low spatial frequency information.     

Activity in ventromedial prefrontal cortex during self-related processing: positive subjective value or personal significance?

Well-being and subjective experience of a coherent world depend on our sense of ‘self’ and relations between the self and the environment (e.g. people, objects and ideas). The ventromedial prefrontal cortex (vMPFC) is involved in self-related processing, and disrupted vMPFC activity is associated with disruptions of emotional/social functioning (e.g. depression and autism). Clarifying precise function(s) of vMPFC in self-related processing is an area of active investigation. In this study, we sought to more specifically characterize the function of vMPFC in self-related processing, focusing on two alternative accounts: (i) assignment of positive subjective value to self-related information and (ii) assignment of personal significance to self-related information. During functional magnetic resonance imaging (fMRI), participants imagined owning objects associated with either their perceived ingroup or outgroup. We found that for ingroup-associated objects, vMPFC showed greater activity for objects with increased than decreased post-ownership preference. In contrast, for outgroup-associated objects, vMPFC showed greater activity for objects with decreased than increased post-ownership preference. Our findings support the idea that the function of vMPFC in self-related processing may not be to represent/evaluate the ‘positivity’ or absolute preference of self-related information but to assign personal significance to it based on its meaning/function for the self.     

Abnormal brain activation and connectivity to standardized disorder‐related visual scenes in social anxiety disorder

Our understanding of altered emotional processing in social anxiety disorder (SAD) is hampered by a heterogeneity of findings, which is probably due to the vastly different methods and materials used so far. This is why the present functional magnetic resonance imaging (fMRI) study investigated immediate disorder‐related threat processing in 30 SAD patients and 30 healthy controls (HC) with a novel, standardized set of highly ecologically valid, disorder‐related complex visual scenes. SAD patients rated disorder‐related as compared with neutral scenes as more unpleasant, arousing and anxiety‐inducing than HC. On the neural level, disorder‐related as compared with neutral scenes evoked differential responses in SAD patients in a widespread emotion processing network including (para‐)limbic structures (e.g. amygdala, insula, thalamus, globus pallidus) and cortical regions (e.g. dorsomedial prefrontal cortex (dmPFC), posterior cingulate cortex (PCC), and precuneus). Functional connectivity analysis yielded an altered interplay between PCC/precuneus and paralimbic (insula) as well as cortical regions (dmPFC, precuneus) in SAD patients, which emphasizes a central role for PCC/precuneus in disorder‐related scene processing. Hyperconnectivity of globus pallidus with amygdala, anterior cingulate cortex (ACC) and medial prefrontal cortex (mPFC) additionally underlines the relevance of this region in socially anxious threat processing. Our findings stress the importance of specific disorder‐related stimuli for the investigation of altered emotion processing in SAD. Disorder‐related threat processing in SAD reveals anomalies at multiple stages of emotion processing which may be linked to increased anxiety and to dysfunctionally elevated levels of self‐referential processing reported in previous studies. Hum Brain Mapp 37:1559‐1572, 2016. © 2016 Wiley Periodicals, Inc.     

Cross‐modal pattern of brain activations associated with the processing of self‐ and significant other's name

Previous neuroimaging studies have shown that the patterns of brain activity during the processing of personally relevant names (e.g., own name, friend's name, partner's name, etc.) and the names of famous people (e.g., celebrities) are different. However, it is not known how the activity in this network is influenced by the modality of the presented stimuli. In this fMRI study, we investigated the pattern of brain activations during the recognition of aurally and visually presented full names of the subject, a significant other, a famous person and unknown individuals. In both modalities, we found that the processing of self‐name and the significant other's name was associated with increased activation in the medial prefrontal cortex (MPFC). Acoustic presentations of these names also activated bilateral inferior frontal gyri (IFG). This pattern of results supports the role of MPFC in the processing of personally relevant information, irrespective of their modality. Hum Brain Mapp 34:2069–2077, 2013. © 2011 Wiley Periodicals, Inc.     

Investigating emotion with music: an fMRI study

The present study used pleasant and unpleasant music to evoke emotion and functional magnetic resonance imaging (fMRI) to determine neural correlates of emotion processing. Unpleasant (permanently dissonant) music contrasted with pleasant (consonant) music showed activations of amygdala, hippocampus, parahippocampal gyrus, and temporal poles. These structures have previously been implicated in the emotional processing of stimuli with (negative) emotional valence; the present data show that a cerebral network comprising these structures can be activated during the perception of auditory (musical) information. Pleasant (contrasted to unpleasant) music showed activations of the inferior frontal gyrus (IFG, inferior Brodmann's area (BA) 44, BA 45, and BA 46), the anterior superior insula, the ventral striatum, Heschl's gyrus, and the Rolandic operculum. IFG activations appear to reflect processes of music-syntactic analysis and working memory operations. Activations of Rolandic opercular areas possibly reflect the activation of mirror-function mechanisms during the perception of the pleasant tunes. Rolandic operculum, anterior superior insula, and ventral striatum may form a motor-related circuitry that serves the formation of (premotor) representations for vocal sound production during the perception of pleasant auditory information. In all of the mentioned structures, except the hippocampus, activations increased over time during the presentation of the musical stimuli, indicating that the effects of emotion processing have temporal dynamics; the temporal dynamics of emotion have so far mainly been neglected in the functional imaging literature.     

Questioning the role of amygdala and insula in an attentional capture by emotional stimuli task

Our senses are constantly monitoring the environment for emotionally salient stimuli that are potentially relevant for survival. Because of our limited cognitive resources, emotionally salient distractors prolong reaction times (RTs) as compared to neutral distractors. In addition, many studies have reported fMRI blood oxygen level‐dependent (BOLD) activation of both the amygdala and the anterior insula for similar valence contrasts. However, a direct correlation of trail‐by‐trial BOLD activity with RTs has not been shown, yet, which would be a crucial piece of evidence to relate the two observations. To investigate the role of the above two regions in the context of emotional distractor effects, we study here the correlation between BOLD activity and RTs for a simple attentional capture by emotional stimuli (ACES) choice reaction time task using a general linear subject‐level model with a parametric RT regressor. We found significant regression coefficients in the anterior insula, supplementary motor cortex, medial precentral regions, sensory‐motor areas and others, but not in the amygdala, despite activation of both insula and amygdala in the traditional valence contrast across trials (i.e., negative vs. neutral pictures). In addition, we found that subjects that exhibit a stronger RT distractor effect across trials also show a stronger BOLD valence contrast in the right anterior insula but not in the amygdala. Our results indicate that the current neuroimaging‐based evidence for the involvement of the amygdala in RT slowing is limited. We advocate that models of emotional capture should incorporate both the amygdala and the anterior insula as separate entities.     

The brain in social context: A systematic review of substance use and social processing from adolescence to young adulthood

Substance use escalates between adolescence and young adulthood, and most experimentation occurs among peers. To understand underlying mechanisms, research has focused on neural response during relevant psychological processes. Functional magnetic resonance imaging (fMRI) research provides a wealth of information about brain activity when processing monetary rewards; however, most studies have used tasks devoid of social stimuli. Given that adolescent neurodevelopment is sculpted by the push-and-pull of peers and emotions, identifying neural substrates is important for intervention. We systematically reviewed 28 fMRI studies examining substance use and neural responses to stimuli including social reward, emotional faces, social influence, and social stressors. We found substance use was positively associated with social-reward activity (e.g., in the ventral striatum), and negatively with social-stress activity (e.g., in the amygdala). For emotion, findings were mixed with more use linked to heightened response (e.g., in amygdala), but also with decreased response (e.g., in insula). For social influence, evidence supported both positive (e.g., cannabis and nucleus accumbens during conformity) and negative (e.g., polydrug and ventromedial PFC during peers’ choices) relations between activity and use. Based on the literature, we offer recommendations for future research on the neural processing of social information to better identify risks for substance use.     

Audition of laughing and crying leads to right amygdala activation in a low-noise fMRI setting

Adequate behavioral responses to socially relevant stimuli are often impaired after lesions of the amygdala. These impaired behavioral responses in particular concern the recognition of facial, and sometimes vocal, expressions of fear. Using low-noise functional magnetic resonance imaging (fMRI) in combination with controlled sound delivery, we investigated how the amygdala, insula and auditory cortex are involved in the processing of affective non-verbal vocalizations (laughing, crying) in healthy humans. The same samples of male and female laughing and crying were presented in two different experimental conditions: self-induction of the corresponding emotions while listening, and detection of artificial pitch shifts in the same stimuli. Both conditions led to bilateral activation of the amygdala, insula and auditory cortex with a right-hemisphere advantage in the amygdala, and larger activation during laughing than crying in the auditory cortex with a slight right-hemisphere advantage for laughing, both likely due to acoustic stimulus features. The results show that amygdala activation by emotionally meaningful sounds like laughing and crying is independent of the emotional involvement, suggesting the pattern recognition aspect of these sounds is crucial for this activation. This aspect was revealed by a low-noise fMRI protocol which presumably minimized confounding effects of stressful high-noise fMRI.     

Attentional modulation of emotional stimulus processing: an fMRI study using emotional expectancy

We used emotional expectancy to study attentional modulation in the processing of emotional stimuli. During functional magnetic resonance imaging (fMRI), volunteers saw emotional and neutral expectancy cues signaling the subsequent presentation of corresponding emotional or neutral pictorial stimuli. As a control, emotional and neutral pictures were presented without preceding expectancy cue, resulting in a 2 x 2 factorial design with the factors "expectancy" and "emotion." Statistical analysis revealed a significant positive interaction effect between these factors in the medial prefrontal cortex (MPFC, Brodmann area [BA] 9/10), amygdala, and dorsal midbrain. In all these regions, expectancy augmented the neural response to emotional but not to neutral pictures. Time course analysis of raw data suggests that this augmented activation was not preceded by baseline increases in MPFC and amygdala during the period of emotional expectancy. In a post-scanning session, the paradigm was presented for a second time to allow emotional intensity rating. Again, a significant interaction between expectancy and emotion was observed, with intensity ratings specifically enhanced in emotional photographs preceded by expectancy. There was a positive correlation between intensity ratings and blood oxygenation level-dependent (BOLD) signals in the left amygdala. We conclude that specific components of the emotion network show enhanced activation in response to emotional stimuli when these are preceded by expectancy. This enhancement effect is not present in neutral pictures and might parallel accentuated subjective feeling states.