Research in bipolar disorder (BD) implicates fronto-limbic-striatal dysfunction during face emotion processing but it is unknown how such dysfunction varies by task demands, face emotion and patient age.
During functional magnetic resonance imaging (fMRI), 181 participants, including 62 BD (36 children and 26 adults) and 119 healthy comparison (HC) subjects (57 children and 62 adults), engaged in constrained and unconstrained processing of emotional (angry, fearful, happy) and non-emotional (neutral) faces. During constrained processing, subjects answered questions focusing their attention on the face; this was processed either implicitly (nose width rating) or explicitly (hostility; subjective fear ratings). Unconstrained processing consisted of passive viewing.
Pediatric BD rated neutral faces as more hostile than did other groups. In BD patients, family-wise error (FWE)-corrected region of interest (ROI) analyses revealed dysfunction in the amygdala, inferior frontal gyrus (IFG), anterior cingulate cortex (ACC) and putamen. Patients with BD showed amygdala hyperactivation during explicit processing (hostility ratings) of fearful faces and passive viewing of angry and neutral faces but IFG hypoactivation during implicit processing of neutral and happy faces. In the ACC and striatum, the direction of dysfunction varied by task demand: BD demonstrated hyperactivation during unconstrained processing of angry or neutral faces but hypoactivation during constrained processing (implicit or explicit) of angry, neutral or happy faces.
Findings suggest amygdala hyperactivation in BD while processing negatively valenced and neutral faces, regardless of attentional condition, and BD IFG hypoactivation during implicit processing. In the cognitive control circuit involving the ACC and putamen, BD neural dysfunction was sensitive to task demands.
Attention; bipolar disorder; face emotion; fronto-limbic-striatal dysfunction; imaging; pediatric
Inability to modulate attention away from emotional stimuli may be a key component of dysregulated emotion in bipolar disorder (BD). Previous studies of BD indicate abnormalities in neural circuitry underlying attentional control, yet few studies examined attentional control in the context of emotional distracters. We compared activity and connectivity in neural circuitry supporting attentional control and emotion processing among 22 individuals with BD type 1, currently remitted and euthymic, and 19 healthy controls. Participants performed an emotional n-back paradigm, comprising high and low attentional demand conditions, each with either emotional (happy, fearful), neutral or no face flanker distracters. During the high attentional control demand conditions without emotional distracters, BD individuals showed reduced activity versus controls in dorsolateral prefrontal cortex, dorsal anterior cingulate cortex (dACC), and inferior parietal cortex. During the high attentional control demand conditions with fearful-face distracters, BD individuals showed greater activity than controls in these regions and amygdala and striatum. Relative to controls, BD individuals also showed abnormal patterns of effective connectivity between dACC and amygdala during high attentional control demand with emotional face distracters. Inter-episode bipolar disorder is characterized by abnormal recruitment of attentional control neural circuitry, especially in the context of emotionally distracting information.
magnetic resonance imaging; attention; working memory; emotion regulation; effective connectivity
Generalized social anxiety disorder (gSAD) is associated with a heightened neural sensitivity to signals that convey threat, as evidenced by exaggerated amygdala and/or insula activation when processing face stimuli that express negative emotions. Less clear in the brain pathophysiology of gSAD are cortical top down control mechanisms that moderate reactivity in these subcortical emotion processing regions. This study evaluated amygdala, insula, and anterior cingulate cortex (ACC) activity in gSAD with a novel “Emotional Faces Shifting Attention Task” (EFSAT), an adaptation of perceptual assessment tasks well-known to elicit amygdala response. In healthy volunteers, the task has been shown to engage the amygdala when attention is directed to emotional faces and the ACC when attention is directed to shapes, away from emotional faces.
During functional MRI, 29 participants with gSAD and 27 healthy controls viewed images comprising a trio of faces (angry, fear, or happy) alongside a trio of geometric shapes (circles, rectangles, or triangles) within the same field of view. Participants were instructed to match faces or match shapes, effectively directing attention towards or away from emotional information, respectively.
Participants with gSAD exhibited greater insula, but not amygdala, activation compared to controls when attending to emotional faces. In contrast, when attention was directed away from faces, controls exhibited ACC recruitment, which was not evident in gSAD. Across participants, greater ACC activation was associated with less insula activation.
Evidence that individuals with gSAD exhibited exaggerated insula reactivity when attending to emotional faces in EFSAT is consistent with other studies suggesting that the neural basis of gSAD may involve insula hyper-reactivity. Furthermore, greater ACC response in controls than gSAD when sustained goal-directed attention is required to shift attention away from social signals, together with a negative relationship between ACC and bilateral insula activity, indicate the ACC may have served a regulatory role when the focus of attention was directed to shapes amidst emotional faces.
Social anxiety; fMRI; Emotional faces; Threat processing; Brain imaging
Individuals vary in the degree to which salient threatening stimuli disrupt or distract from goal-directed cognitive processes. Excessive attention to threat or difficulty resolving the interference created by threat cues could contribute to anxious psychopathology; disruptions in frontal brain regions implicated in attentional control or resolution of emotional interference (e.g. anterior cingulate cortex, “ACC”) might play a role. In this study, we explored the hypothesis that trait anxiety would be associated with ACC activity in an attentional control task with varying levels of threat interference.
During functional magnetic resonance imaging, 20 healthy individuals who varied in trait anxiety levels viewed angry, fearful, and neutral faces superimposed on an indoor or outdoor scene. In a high-threat interference condition, subjects identified the gender of the face (Attend Face). In a low-threat interference condition, they identified the scene type (Attend Scene). Whole-brain analysis was used to compare Attend Face with Attend Scene for angry and fearful (versus neutral) faces. Contrasts were correlated with trait anxiety level.
Behavioral data confirmed that Attend Face produced greater threat interference than Attend Scene. Brain imaging results showed that trait anxiety was inversely associated with bilateral rostral ACC activity for Attend Face relative to Attend Scene for angry faces. A similar relationship was not seen for fearful faces.
The rostral ACC is implicated in assessing the salience of emotional information and controlling attention to resolve emotional interference. The link between higher trait anxiety and decreased ACC activation for angry faces suggests reduced attentional control for signals of interpersonal threat in healthy anxiety-prone individuals.
attention; bias; angry; fearful; brain imaging
Clinical hallmarks of borderline personality disorder (BPD) include social and emotional dysregulation. We tested a model of frontolimbic dysfunction in facial emotion processing in BPD. Groups of 12 unmedicated adults with BPD by DSM-IV and 12 demographically-matched healthy controls (HC) viewed facial expressions (Conditions) of neutral emotion, fear and anger, and made gender discriminations during rapid event-related functional magnetic resonance imaging (fMRI). Analysis of variance of Region of Interest signal change revealed a statistically significant effect of the Group-by-Region-by-Condition interaction. This was due to the BPD group exhibiting a significantly larger magnitude of deactivation (relative to HC) in the bilateral rostral/subgenual anterior cingulate cortex (ACC) to fear and in the left ACC to fear minus neutral; and significantly greater activation in the right amygdala to fear minus neutral. There were no significant between-group differences in ROI signal change in response to anger. In voxel-wise analyses constrained within these ROIs, the BPD group exhibited significant changes in the fear minus neutral contrast, with relatively less activation in the bilateral rostral/subgenual ACC, and greater activation in the right amygdala. In the anger minus neutral contrast this pattern was reversed, with the BPD group showing greater activation in the bilateral rostral/subgenual ACC and less activation in the bilateral amygdala. We conclude that adults with BPD exhibit changes in fronto-limbic activity in the processing of fear stimuli, with exaggerated amygdala response and impaired emotion-modulation of ACC activity. The neural substrates underlying processing of anger may also be altered. These changes may represent an expression of the volumetric and serotonergic deficits observed in these brain areas in BPD.
anterior cingulate cortex; amygdala; fear; anger; functional magnetic resonance imaging
We examined functional connectivity of the amygdala in preadolescent children with Autism Spectrum Disorders (ASDs) during spontaneous attention to eye-gaze in emotional faces. Children responded to a target word (“LEFT/RIGHT”) printed on angry or fearful faces looking in a direction that was congruent, incongruent, or neutral with the target word. Despite being irrelevant to the task, gaze-direction facilitated (Congruent > Neutral) or interfered with (Incongruent > Congruent) performance in both groups. Despite similar behavioral performance, amygdala-connectivity was atypical and more widespread in children with ASD. In control children, the amygdala was more strongly connected with an emotional cognitive control region (subgenual cingulate) during interference, while during facilitation, no regions showed greater amygdala connectivity than in ASD children. In contrast, in children with ASD the amygdala was more strongly connected to salience and cognitive control regions (posterior and dorsal cingulate) during facilitation and with regions involved in gaze processing (superior temporal sulcus), cognitive control (inferior frontal gyrus), and processing of viscerally salient information (pregenual cingulate, anterior insula, and thalamus) during interference. These findings showing more widespread connectivity of the amygdala extend past findings of atypical functional anatomy of eye-gaze processing in children with ASD and challenge views of general underconnectivity in ASD.
Previous studies of cognitive alterations in borderline personality disorder (BPD) have yielded conflicting results. Given that a core feature of BPD is affective instability, which is characterized by emotional hyperreactivity and deficits in emotion regulation, it seems conceivable that short-lasting emotional distress might exert temporary detrimental effects on cognitive performance. Here we used functional magnetic resonance imaging (fMRI) to investigate how task-irrelevant emotional stimuli (fearful faces) affect performance and fronto-limbic neural activity patterns during attention-demanding cognitive processing in 16 female, unmedicated BPD patients relative to 24 age-matched healthy controls. In a modified flanker task, emotionally negative, socially salient pictures (fearful vs. neutral faces) were presented as distracters in the background. Patients, but not controls, showed an atypical response pattern of the right amygdala with increased activation during emotional interference in the (difficult) incongruent flanker condition, but emotion-related amygdala deactivation in the congruent condition. A direct comparison of the emotional conditions between the two groups revealed that the strongest diagnosis-related differences could be observed in the dorsal and, to a lesser extent, also in the rostral anterior cingulate cortex (dACC, rACC) where patients exhibited an increased neural response to emotional relative to neutral distracters. Moreover, in the incongruent condition, both the dACC and rACC fMRI responses during emotional interference were negatively correlated with trait anxiety in the patients, but not in the healthy controls. As higher trait anxiety was also associated with longer reaction times (RTs) in the BPD patients, we suggest that in BPD patients the ACC might mediate compensatory cognitive processes during emotional interference and that such neurocognitive compensation that can be adversely affected by high levels of anxiety.
borderline personality disorder; cognition-emotion interaction; anxiety; fMRI; amygdala; anterior cingulate cortex
Most of our social interactions involve perception of emotional information from the faces of other people. Furthermore, such emotional processes are thought to be aberrant in a range of clinical disorders, including psychosis and depression. However, the exact neurofunctional maps underlying emotional facial processing are not well defined.
Two independent researchers conducted separate comprehensive PubMed (1990 to May 2008) searches to find all functional magnetic resonance imaging (fMRI) studies using a variant of the emotional faces paradigm in healthy participants. The search terms were: “fMRI AND happy faces,” “fMRI AND sad faces,” “fMRI AND fearful faces,” “fMRI AND angry faces,” “fMRI AND disgusted faces” and “fMRI AND neutral faces.” We extracted spatial coordinates and inserted them in an electronic database. We performed activation likelihood estimation analysis for voxel-based meta-analyses.
Of the originally identified studies, 105 met our inclusion criteria. The overall database consisted of 1785 brain coordinates that yielded an overall sample of 1600 healthy participants. Quantitative voxel-based meta-analysis of brain activation provided neurofunctional maps for 1) main effect of human faces; 2) main effect of emotional valence; and 3) modulatory effect of age, sex, explicit versus implicit processing and magnetic field strength. Processing of emotional faces was associated with increased activation in a number of visual, limbic, temporoparietal and prefrontal areas; the putamen; and the cerebellum. Happy, fearful and sad faces specifically activated the amygdala, whereas angry or disgusted faces had no effect on this brain region. Furthermore, amygdala sensitivity was greater for fearful than for happy or sad faces. Insular activation was selectively reported during processing of disgusted and angry faces. However, insular sensitivity was greater for disgusted than for angry faces. Conversely, neural response in the visual cortex and cerebellum was observable across all emotional conditions.
Although the activation likelihood estimation approach is currently one of the most powerful and reliable meta-analytical methods in neuroimaging research, it is insensitive to effect sizes.
Our study has detailed neurofunctional maps to use as normative references in future fMRI studies of emotional facial processing in psychiatric populations. We found selective differences between neural networks underlying the basic emotions in limbic and insular brain regions.
Objective: Automatic emotional processing of faces and facial expressions gain more and more of relevance in terms of social communication. Among a variety of different primes, targets and tasks, whole face images and facial expressions have been used to affectively prime emotional responses. This study investigates whether emotional information provided solely in eye regions that display mental states can also trigger affective priming.
Methods: Sixteen subjects answered a lexical decision task (LDT) coupled with an affective priming paradigm. Emotion-associated eye regions were extracted from photographs of faces and acted as primes, whereas targets were either words or pseudo-words. Participants had to decide whether the targets were real German words or generated pseudo-words. Primes and targets belonged to the emotional categories “fear,” “disgust,” “happiness,” and “neutral.”
Results: A general valence effect for positive words was observed: responses in the LDT were faster for target words of the emotional category happiness when compared to other categories. Importantly, pictures of emotional eye regions preceding the target words affected their subsequent classification. While we show a classical priming effect for neutral target words – with shorter RT for congruent compared to incongruent prime-target pairs- , we observed an inverse priming effect for fearful and happy target words – with shorter RT for incongruent compared to congruent prime-target pairs. These inverse priming effects were driven exclusively by specific prime-target pairs.
Conclusion: Reduced facial emotional information is sufficient to induce automatic implicit emotional processing. The emotional-associated eye regions were processed with respect to their emotional valence and affected the performance on the LDT.
affective priming; lexical decision task; read the mind in the eyes; valence; face
Filmmakers have long recognized the importance of editing techniques to guide the audiences' perceptions and enhance the impact of a scene. We demonstrate behaviorally that pairing identical faces with either neutral or emotionally salient contextual movies, an editing technique referred to as the ‘Kuleshov Effect’, results in both altered attributions of facial expression and mental-state. Using functional neuroimaging (fMRI), we show that faces paired with emotional movies enhance BOLD responses in the bilateral temporal pole, anterior cingulate cortices, amygdala and bilateral superior temporal sulcus relative to identical faces juxtaposed with neutral movies. An interaction was observed in the right amygdala when subtle happy and fear faces were juxtaposed with positive and negative movies, respectively. An interaction between happy faces and negative context was also observed in bilateral amygdala suggesting that the amygdala may act to prime or tag affective value to faces. A parametric modulation of BOLD signal by attribution ratings indicated a dissociation between ventrolateral and the ventromedial prefrontal cortex for negative and positive contextually evoked attributions, respectively. These prefrontal regions may act to guide appropriate choices across altering contexts. Together, these findings offer a neurobiological basis for contextual framing effects on social attributions.
fMRI; kuleshov effect; context; affect; mental-state
Filmmakers have long recognized the importance of editing techniques to guide the audiences' perceptions and enhance the impact of a scene. We demonstrate behaviorally that pairing identical faces with either neutral or emotionally salient contextual movies, an editing technique referred to as the 'Kuleshov Effect', results in both altered attributions of facial expression and mental-state. Using functional neuroimaging (fMRI), we show that faces paired with emotional movies enhance BOLD responses in the bilateral temporal pole, anterior cingulate cortices, amygdala and bilateral superior temporal sulcus relative to identical faces juxtaposed with neutral movies. An interaction was observed in the right amygdala when subtle happy and fear faces were juxtaposed with positive and negative movies, respectively. An interaction between happy faces and negative context was also observed in bilateral amygdala suggesting that the amygdala may act to prime or tag affective value to faces. A parametric modulation of BOLD signal by attribution ratings indicated a dissociation between ventrolateral and the ventromedial prefrontal cortex for negative and positive contextually evoked attributions, respectively. These prefrontal regions may act to guide appropriate choices across altering contexts. Together, these findings offer a neurobiological basis for contextual framing effects on social attributions.
fMRI; kuleshov effect; context; affect; mental-state
Emotion regulation is a critical aspect of children's social development, yet few studies have examined the brain mechanisms involved in the development of emotion regulation. Theoretical accounts have conceptualized emotion regulation as relying upon prefrontal control of limbic regions, specifying the anterior cingulate cortex (ACC) as a key brain region for the regulation of emotion. Functional magnetic resonance imaging (fMRI) in 5- to 11-year-olds during emotion regulation and processing of emotionally expressive faces revealed that older children preferentially recruited the more dorsal “cognitive” areas of the ACC, while younger children preferentially engaged the more ventral “emotional” areas. Additionally, children with more fearful temperaments exhibited more ventral ACC activity while less fearful children exhibited increased activity in the dorsal ACC. These findings provide insight into a potential neurobiological mechanism underlying well-documented behavioral and cognitive changes from more emotional to more cognitive regulatory strategies with increasing age, as well as individual differences in this developmental process as a function of temperament. Our results hold important implications for our understanding of normal development and should also help to inform our understanding and management of emotional disorders.
Emotion Regulation; Development; fMRI; Anterior Cingulate; Temperament
Manelis et al. use fMRI to compare implicit processing of emotional faces in the offspring of individuals with bipolar disorder, non-bipolar psychopathology and no psychopathology. Reduced amygdala-ACC functional connectivity and increased amygdala-VLPFC functional connectivity distinguishes the offspring of bipolar parents from other participants, and may be a bipolar disorder biomarker.
Manelis et al. use fMRI to compare implicit processing of emotional faces in the offspring of individuals with bipolar disorder, non-bipolar psychopathology and no psychopathology. Reduced amygdala-ACC functional connectivity and increased amygdala-VLPFC functional connectivity distinguishes the offspring of bipolar parents from other participants, and may be a bipolar disorder biomarker.
This study aimed to identify neuroimaging measures associated with risk for, or protection against, bipolar disorder by comparing youth offspring of parents with bipolar disorder versus youth offspring of non-bipolar parents versus offspring of healthy parents in (i) the magnitude of activation within emotional face processing circuitry; and (ii) functional connectivity between this circuitry and frontal emotion regulation regions. The study was conducted at the University of Pittsburgh Medical Centre. Participants included 29 offspring of parents with bipolar disorder (mean age = 13.8 years; 14 females), 29 offspring of non-bipolar parents (mean age = 13.8 years; 12 females) and 23 healthy controls (mean age = 13.7 years; 11 females). Participants were scanned during implicit processing of emerging happy, sad, fearful and angry faces and shapes. The activation analyses revealed greater right amygdala activation to emotional faces versus shapes in offspring of parents with bipolar disorder and offspring of non-bipolar parents than healthy controls. Given that abnormally increased amygdala activation during emotion processing characterized offspring of both patient groups, and that abnormally increased amygdala activation has often been reported in individuals with already developed bipolar disorder and those with major depressive disorder, these neuroimaging findings may represent markers of increased risk for affective disorders in general. The analysis of psychophysiological interaction revealed that offspring of parents with bipolar disorder showed significantly more negative right amygdala-anterior cingulate cortex functional connectivity to emotional faces versus shapes, but significantly more positive right amygdala-left ventrolateral prefrontal cortex functional connectivity to happy faces (all P-values corrected for multiple tests) than offspring of non-bipolar parents and healthy controls. Taken together with findings of increased amygdala-ventrolateral prefrontal cortex functional connectivity, and decreased amygdala-anterior cingulate cortex functional connectivity previously shown in individuals with bipolar disorder, these connectivity patterns in offspring of parents with bipolar disorder may be risk markers for, rather than markers conferring protection against, bipolar disorder in youth. The patterns of activation and functional connectivity remained unchanged after removing medicated participants and those with current psychopathology from analyses. This is the first study to demonstrate that abnormal functional connectivity patterns within face emotion processing circuitry distinguish offspring of parents with bipolar disorder from those of non-bipolar parents and healthy controls.
youth offspring of parents with bipolar disorder; risk of bipolar disorder; functional MRI; emotion processing; emotion regulation; biological markers
Neuropsychiatric fluctuations in Parkinson's disease (PD) are frequent and disabling. One way to investigate them is to assess the ability to inhibit distractive emotional information by a modified emotional Stroop (ES) task. We compared non-depressed, non-demented PD patients with healthy controls. During an acute levodopa challenge, patients performed a modified ES task during functional MRI and a neuropsychological assessment including Visual Analog Mood (VAMS) and Apathy scales. Ten patients and 12 controls completed the study. The VAMS scores were significantly improved by the acute intake of levodopa (p = 0.02), as was the apathy score (p = 0.03). Negative ES task (i.e. fearful facial expressions with the words “happy” or “fear” written across them), induced a lengthening of the mean reaction time during the incongruent trials compared with the congruent trials in controls (relative difference = 2.7%, p < 0.001) and in ON patients (relative difference = 5.9%, p < 0.001), but not in OFF patients (relative difference = 1.7%, p = 0.28). Controls and ON patients displayed greater activation than OFF patients within the right pregenual anterior cingulate cortex (pACC), an area specifically involved in emotional conflict resolution (p < 0.001 and p < 0.008 respectively, k > 5 uncorrected). No difference in the activation of the pACC was found between controls and ON patients, suggesting a normalization of the activation following levodopa administration. These results suggest that emotional conflict processes could be dopamine-dependent. Pregenual ACC hypoactivation could be directly due to the degeneration of dopaminergic mesocorticolimbic pathway. Our results propose that neuropsychiatric fluctuations in PD patients could be partially explained by pACC hypoactivation and that adjustments of dopaminergic medication might be helpful for their treatment.
emotional stroop; dopamine; Parkinson's disease; cingulate cortex; non-motor fluctuations
In the context of emotion information processing, several studies have demonstrated the involvement of the amygdala in emotion perception, for unimodal and multimodal stimuli. However, it seems that not only the amygdala, but several regions around it, may also play a major role in multimodal emotional integration. In order to investigate the contribution of these regions to multimodal emotion perception, five patients who had undergone unilateral anterior temporal lobe resection were exposed to both unimodal (vocal or visual) and audiovisual emotional and neutral stimuli. In a classic paradigm, participants were asked to rate the emotional intensity of angry, fearful, joyful, and neutral stimuli on visual analog scales. Compared with matched controls, patients exhibited impaired categorization of joyful expressions, whether the stimuli were auditory, visual, or audiovisual. Patients confused joyful faces with neutral faces, and joyful prosody with surprise. In the case of fear, unlike matched controls, patients provided lower intensity ratings for visual stimuli than for vocal and audiovisual ones. Fearful faces were frequently confused with surprised ones. When we controlled for lesion size, we no longer observed any overall difference between patients and controls in their ratings of emotional intensity on the target scales. Lesion size had the greatest effect on intensity perceptions and accuracy in the visual modality, irrespective of the type of emotion. These new findings suggest that a damaged amygdala, or a disrupted bundle between the amygdala and the ventral part of the occipital lobe, has a greater impact on emotion perception in the visual modality than it does in either the vocal or audiovisual one. We can surmise that patients are able to use the auditory information contained in multimodal stimuli to compensate for difficulty processing visually conveyed emotion.
amygdala; emotion perception; multimodal; prosody; facial expression
Pregenual anterior cingulate cortex (pgACC) hyperactivity differentiates treatment responders from non-responders to various pharmacological antidepressant interventions, including ketamine, an N-methyl--aspartate receptor antagonist. Evidence of pgACC hyperactivition during non-emotional working memory tasks in patients with major depressive disorder (MDD) highlights the importance of this region for processing both emotionally salient and cognitive stimuli. However, it is unclear whether pgACC activity might serve as a potential biomarker of antidepressant response during working memory tasks as well, in line with previous research with emotionally arousing tasks. This study tested the hypothesis that during the N-back task, a widely used working memory paradigm, low pretreatment pgACC activity, as well as coherence between the pgACC and the amygdala, would be correlated with the clinical improvement after ketamine. Magnetoencephalography (MEG) recordings were obtained from 15 drug-free patients with MDD during working memory performance 1 to 3 days before receiving a single ketamine infusion. Functional activation patterns were analyzed using advanced MEG source analysis. Source coherence analyses were conducted to quantify the degree of long-range functional connectivity between the pgACC and the amygdala. Patients who showed the least engagement of the pgACC in response to increased working memory load showed the greatest symptomatic improvement within 4 h of ketamine administration (r=0.82, p=0.0002, false discovery rate (FDR) <0.05). Pretreatment functional connectivity between the pgACC and the left amygdala was negatively correlated with antidepressant symptom change (r=−0.73, p=0.0021, FDR <0.05).These data implicate the pgACC and its putative interaction with the amygdala in predicting antidepressant response to ketamine in a working memory task context.
major depressive disorder (MDD); magnetoencephalography (MEG); N-back; biomarker; beta desynchronization; Biological Psychiatry; Mood/Anxiety/Stress Disorders; Imaging; Clinical or Preclinical; Glutamate; magnetoencephalography; N-back; beta desynchronization; biomarker
While social phobia (SP) in adolescence predicts risk for SP in adulthood, no work has directly compared neural responses in SP adults and adolescents. The current study examines neural response to facial expressions in adult and adolescent SP to determine whether the neural correlates of adult SP during face processing also manifest in adolescent SP.
Blood oxygen level-dependent (BOLD) was compared in 39 medication-free individuals with SP (25 adults and 14 adolescents), and 39 healthy comparison individuals (23 adult and 16 adolescent) matched on age, IQ, and gender using functional magnetic resonance imaging (fMRI). During fMRI scans, individuals saw angry, fearful, and neutral expression stimuli while making a gender judgment.
Hypothesized significant diagnosis-by-emotion interactions were observed within the amygdala and rostral anterior cingulate cortex (rACC). In these regions, the adolescent and adult SP patients both showed significantly increased BOLD responses, relative to their respective age-matched comparison groups, with no evidence of age-related modulation of between-group differences. These enhanced responses occurred specifically to angry (rACC) and fearful (amygdala and rACC) but not neutral expressions. In addition, SP severity correlated significantly with this enhanced rACC response in the adults.
The neural correlates of adult SP during face processing also manifest in adolescents. As such, neural correlates observed in adult SP may represent the persistence of profiles established earlier in life, rather than adaptive responses to such earlier perturbations or maturational changes. These cross-sectional observations might encourage longitudinal fMRI studies of adolescent SP.
Facial expression perception can be influenced by the natural visual context in which the face is perceived. We performed an fMRI experiment presenting participants with fearful or neutral faces against threatening or neutral background scenes. Triangles and scrambled scenes served as control stimuli. The results showed that the valence of the background influences face selective activity in the right anterior parahippocampal place area (PPA) and subgenual anterior cingulate cortex (sgACC) with higher activation for neutral backgrounds compared to threatening backgrounds (controlled for isolated background effects) and that this effect correlated with trait empathy in the sgACC. In addition, the left fusiform gyrus (FG) responds to the affective congruence between face and background scene. The results show that valence of the background modulates face processing and support the hypothesis that empathic processing in sgACC is inhibited when affective information is present in the background. In addition, the findings reveal a pattern of complex scene perception showing a gradient of functional specialization along the posterior–anterior axis: from sensitivity to the affective content of scenes (extrastriate body area: EBA and posterior PPA), over scene emotion–face emotion interaction (left FG) via category–scene interaction (anterior PPA) to scene–category–personality interaction (sgACC).
face; scene; emotion; ACC; PPA
Functional neuroimaging studies have largely established the prominence of amygdala during emotion processing and prefrontal areas such as anterior cingulate cortex (ACC) during attentional modulation. In general, emotion processing paradigms known to probe amygdala have not been adapted to recruit prefrontal areas. In this study we used a well-known perceptual face matching paradigm, designed to elicit amygdala response, and asked volunteers to shift their focus in order to recruit regions responsible for attentional control. Stimuli comprised a trio of geometric shapes (circles, rectangles, triangles) presented alongside a trio of emotional faces (angry, fear, or happy) within the same field of view, and subjects were instructed to Match Faces or Match Shapes, as a means of attending to and away from the emotional content, respectively. We observed greater amygdala reactivity to Match Faces (>Match Shapes), and greater rostral ACC response to Match Shapes (>Match Faces). Results indicate that simply and volitionally directing attention towards or away from emotional content correspondingly modulates amygdala and ACC activity.
Emotion and reward have been proposed to be closely linked to conscious experience, but empirical data are lacking. The anterior cingulate cortex (ACC) plays a central role in the hedonic dimension of conscious experience; thus potentially a key region in interactions between emotion and consciousness. Here we tested the impact of emotion on conscious experience, and directly investigated the role of the ACC. We used a masked paradigm that measures conscious reportability in terms of subjective confidence and objective accuracy in identifying the briefly presented stimulus in a forced-choice test. By manipulating the emotional valence (positive, neutral, negative) and the presentation time (16 ms, 32 ms, 80 ms) we measured the impact of these variables on conscious and subliminal (i.e. below threshold) processing. First, we tested normal participants using face and word stimuli. Results showed that participants were more confident and accurate when consciously seeing happy versus sad/neutral faces and words. When stimuli were presented subliminally, we found no effect of emotion. To investigate the neural basis of this impact of emotion, we recorded local field potentials (LFPs) directly in the ACC in a chronic pain patient. Behavioural findings were replicated: the patient was more confident and accurate when (consciously) seeing happy versus sad faces, while no effect was seen in subliminal trials. Mirroring behavioural findings, we found significant differences in the LFPs after around 500 ms (lasting 30 ms) in conscious trials between happy and sad faces, while no effect was found in subliminal trials. We thus demonstrate a striking impact of emotion on conscious experience, with positive emotional stimuli enhancing conscious reportability. In line with previous studies, the data indicate a key role of the ACC, but goes beyond earlier work by providing the first direct evidence of interaction between emotion and conscious experience in the human ACC.
Individuals with bipolar disorder demonstrate abnormal social function. Neuroimaging studies in bipolar disorder have shown functional abnormalities in neural circuitry supporting face emotion processing, but have not examined face identity processing, a key component of social function. We aimed to elucidate functional abnormalities in neural circuitry supporting face emotion and face identity processing in bipolar disorder.
Twenty-seven individuals with bipolar disorder I currently euthymic and 27 healthy controls participated in an implicit face processing, block-design paradigm. Participants labeled color flashes that were superimposed on dynamically changing background faces comprising morphs either from neutral to prototypical emotion (happy, sad, angry and fearful) or from one identity to another identity depicting a neutral face. Whole-brain and amygdala region-of-interest (ROI) activities were compared between groups.
There was no significant between-group difference looking across both emerging face emotion and identity. During processing of all emerging emotions, euthymic individuals with bipolar disorder showed significantly greater amygdala activity. During facial identity and also happy face processing, euthymic individuals with bipolar disorder showed significantly greater amygdala and medial prefrontal cortical activity compared with controls.
This is the first study to examine neural circuitry supporting face identity and face emotion processing in bipolar disorder. Our findings of abnormally elevated activity in amygdala and medial prefrontal cortex (mPFC) during face identity and happy face emotion processing suggest functional abnormalities in key regions previously implicated in social processing. This may be of future importance toward examining the abnormal self-related processing, grandiosity and social dysfunction seen in bipolar disorder.
Affective disorders; amygdala; bipolar disorder; face processing; functional magnetic resonance imaging; identity processing; medial prefrontal cortex; morph; self-processing; social processing
Generalized social anxiety disorder (gSAD) is characterized by exaggerated amygdala reactivity to social signals of threat, but if and how the amygdala interacts with functionally and anatomically connected prefrontal cortex (PFC) remains largely unknown. Recent evidence points to aberrant amygdala connectivity to medial PFC in gSAD at rest, but it is difficult to attribute functional relevance without the context of threat processing. Here, we address this by studying amygdala-frontal cortex connectivity during viewing of fearful faces and at rest in gSAD patients.
Twenty patients with gSAD and 17 matched healthy controls (HCs) participated in functional magnetic resonance imaging of an emotional face matching task, and a resting state task. Functional connectivity and psychophysiological interaction analysis were used to assess amygdala connectivity.
Compared to HCs, gSAD patients exhibited less connectivity between amygdala and the rostral anterior cingulate cortex (ACC) and dorsolateral prefrontal cortex (DLPFC) while viewing fearful faces. gSAD patients also showed less connectivity between amygdala and rostral ACC at rest in the absence of fearful faces. DLPFC connectivity was negatively correlated with LSASFear.
Task and rest paradigms provide unique and important information about discrete and overlapping functional networks. In particular, amygdala coupling to DLPFC may be a phasic abnormality, emerging only in the presence of a social predictor of threat, whereas amygdala coupling to the rostral ACC may reflect both phasic and tonic abnormalities. These findings prompt further studies to better delineate intrinsic and externally-evoked brain connectivity in anxiety and depression in relation to amygdala dysfunction.
Amygdala; ACC; DLPFC; Connectivity; Social Phobia; PPI
Emotional information is frequently processed below the level of consciousness, where subcortical regions of the brain are thought to play an important role. In the absence of conscious visual experience, patients with visual cortex damage discriminate the valence of emotional expression. Even in healthy individuals, a subliminal mechanism can be utilized to compensate for a functional decline in visual cognition of various causes such as strong sleepiness. In this study, sleep deprivation was simulated in healthy individuals to investigate functional alterations in the subliminal processing of emotional information caused by reduced conscious visual cognition and attention due to an increase in subjective sleepiness. Fourteen healthy adult men participated in a within-subject crossover study consisting of a 5-day session of sleep debt (SD, 4-h sleep) and a 5-day session of sleep control (SC, 8-h sleep). On the last day of each session, participants performed an emotional face-viewing task that included backward masking of nonconscious presentations during magnetic resonance scanning.
Finally, data from eleven participants who were unaware of nonconscious face presentations were analyzed. In fear contrasts, subjective sleepiness was significantly positively correlated with activity in the amygdala, ventromedial prefrontal cortex, hippocampus, and insular cortex, and was significantly negatively correlated with the secondary and tertiary visual areas and the fusiform face area. In fear-neutral contrasts, subjective sleepiness was significantly positively correlated with activity of the bilateral amygdala. Further, changes in subjective sleepiness (the difference between the SC and SD sessions) were correlated with both changes in amygdala activity and functional connectivity between the amygdala and superior colliculus in response to subliminal fearful faces.
Sleepiness induced functional decline in the brain areas involved in conscious visual cognition of facial expressions, but also enhanced subliminal emotional processing via superior colliculus as represented by activity in the amygdala. These findings suggest that an evolutionally old and auxiliary subliminal hazard perception system is activated as a compensatory mechanism when conscious visual cognition is impaired. In addition, enhancement of subliminal emotional processing might cause involuntary emotional instability during sleep debt through changes in emotional response to or emotional evaluation of external stimuli.
Sleepiness; Nonconscious; Unconscious; Subliminal; Emotion; Fearful face; Amygdala
Individuals with generalized social anxiety disorder (gSAD) exhibit attentional bias to salient stimuli, which is reduced in patients whose symptoms improve after treatment, indicating that mechanisms of bias mediate treatment success. Therefore, pre-treatment activity in regions implicated in attentional control over socio-emotional signals (e.g. anterior cingulate cortex, dorsolateral prefrontal cortex) may predict response to cognitive behavioral therapy (CBT), evidence-based psychotherapy for gSAD.
During functional magnetic resonance imaging, 21 participants with gSAD viewed images comprising a trio of geometric shapes (circles, rectangles or triangles) alongside a trio of faces (angry, fearful or happy) within the same field of view. Attentional control was evaluated with the instruction to ‘match shapes’, directing attention away from faces, which was contrasted with ‘match faces’, whereby attention was directed to emotional faces.
Whole-brain voxel-wise analyses showed that symptom improvement was predicted by enhanced pre-treatment activity in the presence of emotional face distractors in the dorsal anterior cingulate cortex and dorsal medial pre-frontal cortex. Additionally, CBT success was foretold by less activity in the amygdala and/or increased activity in the medial orbitofrontal gyrus during emotion processing.
CBT response was predicted by pre-treatment activity in prefrontal regions and the amygdala. The direction of activity suggests that individuals with intact attentional control in the presence of emotional distractors, regulatory capacity over emotional faces and/or less reactivity to such faces are more likely to benefit from CBT. Findings indicate that baseline neural activity in the context of attentional control and emotion processing may serve as a step towards delineating mechanisms by which CBT exerts its effects.
Attentional control; brain imaging; neural predictors; psychotherapy; social anxiety
It is unclear whether reflective awareness of emotions is related to extent and intensity of implicit affective reactions. This study is the first to investigate automatic brain reactivity to emotional stimuli as a function of trait emotional awareness. To assess emotional awareness the Levels of Emotional Awareness Scale (LEAS) was administered. During scanning, masked happy, angry, fearful and neutral facial expressions were presented to 46 healthy subjects, who had to rate the fit between artificial and emotional words. The rating procedure allowed assessment of shifts in implicit affectivity due to emotion faces. Trait emotional awareness was associated with increased activation in the primary somatosensory cortex, inferior parietal lobule, anterior cingulate gyrus, middle frontal and cerebellar areas, thalamus, putamen and amygdala in response to masked happy faces. LEAS correlated positively with shifts in implicit affect caused by masked happy faces. According to our findings, people with high emotional awareness show stronger affective reactivity and more activation in brain areas involved in emotion processing and simulation during the perception of masked happy facial expression than people with low emotional awareness. High emotional awareness appears to be characterized by an enhanced positive affective resonance to others at an automatic processing level.
emotional awareness; implicit affect; automatic emotion processing; neuroimaging