Processing Facial Expressions Of Emotion Research Articles

Functional connectivity between the amygdala and prefrontal cortex underlies processing of emotion ambiguity

Processing facial expressions of emotion draws on a distributed brain network. In particular, judging ambiguous facial emotions involves coordination between multiple brain areas. Here, we applied multimodal functional connectivity analysis to achieve network-level understanding of the neural mechanisms underlying perceptual ambiguity in facial expressions. We found directional effective connectivity between the amygdala, dorsomedial prefrontal cortex (dmPFC), and ventromedial PFC, supporting both bottom-up affective processes for ambiguity representation/perception and top-down cognitive processes for ambiguity resolution/decision. Direct recordings from the human neurosurgical patients showed that the responses of amygdala and dmPFC neurons were modulated by the level of emotion ambiguity, and amygdala neurons responded earlier than dmPFC neurons, reflecting the bottom-up process for ambiguity processing. We further found parietal-frontal coherence and delta-alpha cross-frequency coupling involved in encoding emotion ambiguity. We replicated the EEG coherence result using independent experiments and further showed modulation of the coherence. EEG source connectivity revealed that the dmPFC top-down regulated the activities in other brain regions. Lastly, we showed altered behavioral responses in neuropsychiatric patients who may have dysfunctions in amygdala-PFC functional connectivity. Together, using multimodal experimental and analytical approaches, we have delineated a neural network that underlies processing of emotion ambiguity.

The role of stimulus-based cues and conceptual information in processing facial expressions of emotion

Face shape and surface textures are two important cues that aid in the perception of facial expressions of emotion. Additionally, this perception is also influenced by high-level emotion concepts. Across two studies, we use representational similarity analysis to investigate the relative roles of shape, surface, and conceptual information in the perception, categorisation, and neural representation of facial expressions. In Study 1, 50 participants completed a perceptual task designed to measure the perceptual similarity of expression pairs, and a categorical task designed to measure the confusability between expression pairs when assigning emotion labels to a face. We used representational similarity analysis and constructed three models of the similarities between emotions using distinct information. Two models were based on stimulus-based cues (face shapes and surface textures) and one model was based on emotion concepts. Using multiple linear regression, we found that behaviour during both tasks was related with the similarity of emotion concepts. The model based on face shapes was more related with behaviour in the perceptual task than in the categorical, and the model based on surface textures was more related with behaviour in the categorical than the perceptual task. In Study 2, 30 participants viewed facial expressions while undergoing fMRI, allowing for the measurement of brain representational geometries of facial expressions of emotion in three core face-responsive regions (the Fusiform Face Area, Occipital Face Area, and Superior Temporal Sulcus), and a region involved in theory of mind (Medial Prefrontal Cortex). Across all four regions, the representational distances between facial expression pairs were related to the similarities of emotion concepts, but not to either of the stimulus-based cues. Together, these results highlight the important top-down influence of high-level emotion concepts both in behavioural tasks and in the neural representation of facial expressions.

Dysfunction of processing task-irrelevant emotional faces in primary insomnia patients: an evidence from expression-related visual MMN

According to the cognitive processing perspectives, patients with insomnia have insufficient neural management of expressional information. In this study, we compared the pre-attentive processing function of task-irrelevant facial expressions in patients with primary insomnia (PI) and matched healthy controls, with expression-related mismatch negativity (EMMN) elicited by emotional faces as the indicator. Using three schematic facial expressions (neutral, happy, and sad) as task-irrelevant stimuli, we investigated the visual processing of PI patients (n = 22) and healthy subjects (n = 22) in an expression-related oddball paradigm designed to elicit the visual N170 and EMMN component. After recording and analyzing the electroencephalogram of all participants, amplitude analysis of N170 and EMMN was eventually conducted under corresponding time window. Compared with control group, the amplitude of sad-EMMN component was significantly attenuated in patients with PI, while no remarkable difference was observed under the happy condition. In addition, negative cognitive bias was further validated in the control group, but not presented in the PI group. The current data suggest dysfunctional expressional information processing in PI patients, accompanied by the disorganization of high level perceptual strategy of processing facial emotional expression.

Processing Facial Expressions of Emotion: Upright vs. Inverted Images

We studied discrimination of briefly presented upright vs. inverted emotional facial expressions (FEs), hypothesizing that inversion would impair emotion decoding by disrupting holistic FE processing. Stimuli were photographs of seven emotion prototypes, of a male and female poser (Ekman and Friesen, 1976), and eight intermediate morphs in each set. Subjects made speeded Same/Different judgments of emotional content for all upright (U) or inverted (I) pairs of FEs, presented for 500 ms, 100 times each pair. Signal Detection Theory revealed the sensitivity measure d′ to be slightly but significantly higher for the upright FEs. In further analysis using multidimensional scaling (MDS), percentages of Same judgments were taken as an index of pairwise perceptual similarity, separately for U and I presentation mode. The outcome was a 4D “emotion expression space,” with FEs represented as points and the dimensions identified as Happy–Sad, Surprise/Fear, Disgust, and Anger. The solutions for U and I FEs were compared by means of cophenetic and canonical correlation, Procrustes analysis, and weighted-Euclidean analysis of individual differences. Differences in discrimination produced by inverting FE stimuli were found to be small and manifested as minor changes in the MDS structure or weights of the dimensions. Solutions differed substantially more between the two posers, however. Notably, for stimuli containing elements of Happiness (whether U or I), the MDS structure showed signs of implicit categorization, indicating that mouth curvature – the dominant feature conveying Happiness – is visually salient and receives early processing. The findings suggest that for briefly presented FEs, Same/Different decisions are dominated by low-level visual analysis of abstract patterns of lightness and edge filters, but also reflect emerging featural analysis. These analyses, insensitive to face orientation, enable initial positive/negative Valence categorization of FEs.

Facial emotion triggered cerebral potentials in treatment-resistant depression and borderline personality disorder patients of both genders

Processing facial expressions of emotion is deteriorated in depression, which might be more pronounced in treatment-resistant depression (TRD), especially when the latter is comorbid with borderline personality disorder (BPD). Neurophysiologically, both early perceptual and late cognitive cerebral processes of facial emotions can be illustrated by event-related potentials (ERPs). We therefore tried the ERPs to facial expressions of Neutral, Anger, Happiness, and Sadness in 25 patients with TRD, 15 with BPD, 22 with their comorbidity (TRD+BPD), as well as in 37 healthy volunteers. The depression levels of participants were measured with the Plutchik-van Praag Depressive Inventory (PVP). There was no group difference regarding either N1 (N170), P2, N2, P3a or P3b latency or amplitude to the four facial emotions. Reaction times (RTs) to Anger (p<.01), Happiness (p<.01), and Sadness (p<.001) in TRD, and those to Anger (p<.01) and Happiness (p<.01) in TRD+BPD patients were longer than those in the healthy volunteers. RTs to the four facial expressions were positively correlated (p<.01) with their depressive moods in all participants. In addition, PVP was positively correlated with the P2 latency to Anger in TRD+BPD patients (Fz, p<.01; Cz, p<.01; Pz, p<.01). BPD contributed little to TRD or TRD+BPD regarding cerebral processing of facial emotions, however, other cognitive and behavioral data suggest a generalized impairment when responding to facial emotions in TRD and TRD+BPD patients, and a deteriorated perceptual processing of Anger in TRD+BPD patients.

Emotional Modulation of Attention: Fear Increases but Disgust Reduces the Attentional Blink

BackgroundIt is well known that facial expressions represent important social cues. In humans expressing facial emotion, fear may be configured to maximize sensory exposure (e.g., increases visual input) whereas disgust can reduce sensory exposure (e.g., decreases visual input). To investigate whether such effects also extend to the attentional system, we used the “attentional blink” (AB) paradigm. Many studies have documented that the second target (T2) of a pair is typically missed when presented within a time window of about 200–500 ms from the first to-be-detected target (T1; i.e., the AB effect). It has recently been proposed that the AB effect depends on the efficiency of a gating system which facilitates the entrance of relevant input into working memory, while inhibiting irrelevant input. Following the inhibitory response on post T1 distractors, prolonged inhibition of the subsequent T2 is observed. In the present study, we hypothesized that processing facial expressions of emotion would influence this attentional gating. Fearful faces would increase but disgust faces would decrease inhibition of the second target.Methodology/Principal FindingsWe showed that processing fearful versus disgust faces has different effects on these attentional processes. We found that processing fear faces impaired the detection of T2 to a greater extent than did the processing disgust faces. This finding implies emotion-specific modulation of attention.Conclusions/SignificanceBased on the recent literature on attention, our finding suggests that processing fear-related stimuli exerts greater inhibitory responses on distractors relative to processing disgust-related stimuli. This finding is of particular interest for researchers examining the influence of emotional processing on attention and memory in both clinical and normal populations. For example, future research could extend upon the current study to examine whether inhibitory processes invoked by fear-related stimuli may be the mechanism underlying the enhanced learning of fear-related stimuli.

Bipolar patients show mood‐congruent biases in sensitivity to facial expressions of emotion when exhibiting depressed symptoms, but not when exhibiting manic symptoms

Introduction A number of studies have reported mood‐congruent biases in processing facial expressions of emotion in depression and mania. Most of them have failed to establish that mood reliably affects relevant more than irrelevant expressions, or that the effect is specifically mood‐related rather than due to resource or task difficulty artefacts. The aim was to examine, using appropriate statistical methods, whether depressed mood in bipolar patients decreases and manic mood increases sensitivity to facial expressions of happiness and vice versa for facial expressions of negative emotion. Methods Sensitivity to facial expression of six basic emotions in bipolar patients when depressed and when manic was compared to closely matched controls. Results Mood‐related biases in sensitivity to facial expressions of happiness and of negative affect in general operate in persons with bipolar disorder when depressed. There is little evidence of similar biases in persons with bipolar disorder when manic. Conclusions These data show a mood‐congruent bias in sensitivity to facial expressions in bipolar depressed patients.

Autism and the development of face processing

Autism is a pervasive developmental condition, characterized by impairments in non-verbal communication, social relationships and stereotypical patterns of behavior. A large body of evidence suggests that several aspects of face processing are impaired in autism, including anomalies in gaze processing, memory for facial identity and recognition of facial expressions of emotion. In search of neural markers of anomalous face processing in autism, much interest has focused on a network of brain regions that are implicated in social cognition and face processing. In this review, we will focus on three such regions, namely the STS for its role in processing gaze and facial movements, the FFA in face detection and identification and the amygdala in processing facial expressions of emotion. Much evidence suggests that a better understanding of the normal development of these specialized regions is essential for discovering the neural bases of face processing anomalies in autism. Thus, we will also examine the available literature on the normal development of face processing. Key unknowns in this research area are the neuro-developmental processes, the role of experience and the interactions among components of the face processing system in shaping each of the specialized regions for processing faces during normal development and in autism.

An event-related potential study of the processing of affective facial expressions in young children who experienced maltreatment during the first year of life

This investigation examined the effects of maltreatment during the first year of life on the neural correlates of processing facial expressions of emotion at 30 months of age. Event-related potentials (ERPs) in response to children passively viewing standardized pictures of female models posing angry, happy, and neutral facial expressions were examined. Four ERP waveform components were derived: early negative (N150), early positive (P260), negative central (Nc), and positive slow wave (PSW). Differences in these waveforms between a group of 35 maltreated and 24 nonmaltreated children were reported. The groups did not differ on the early perceptual negative component (N150), whereas the maltreated children had greater P260 amplitude at frontal leads compared to the nonmaltreated children in response to viewing angry facial expressions. For the Nc component, the nonmaltreated comparison children exhibited greater amplitude while viewing pictures of happy faces compared to angry and neutral faces, whereas the maltreated children showed greater Nc amplitude at central sites while viewing angry faces. For the PSW, the nonmaltreated group showed a greater area score in the right hemisphere in response to viewing angry facial expressions compared to the maltreated group. The results are discussed in terms of brain development and function, as well as their implications for the design and evaluation of preventive interventions.

Recognition of Facial Expressions of Emotion by Patients with Dementia of the Alzheimer Type

Bilateral amygdala damage has been linked with an inability to recognise facial expressions of emotion, particularly the expression of fear. Patients with Alzheimer’s disease (AD) suffer from atrophy of the amygdala at an early stage of the disease. It was therefore predicted that AD patients would have more difficulty in two tasks of processing facial expressions of emotion. Thirteen patients diagnosed with probable AD referred to the Oxford Project to Investigate Memory and Ageing (OPTIMA) and 13 age-matched controls enrolled in the programme participated in the study. Participants were shown two tasks, one involved recognising and labelling a target expression, the other matching a target expression with one of four others. The results showed that compared with the controls, the patients were not impaired in recognising any facial expressions of emotion in the labelling task, but were impaired in matching three facial expressions of emotion in the second task. It was speculated that the impairment in the matching task could have been a result of visuospatial dysfunction rather than one of processing emotions.

Verbal Involvement of the Left Hemisphere in Processing Facial Expressions of Emotion

Verbal involvement of the left hemisphere in processing facial expressions of emotion was investigated with normal subjects by examining the effects for hemispheres (right or left hemisphere), stimulus processing codes (imagery or verbal code), and the degree of cognitive demands of the task (unilateral or bilateral tachistoscopic projection) on accuracy for recognizing emotional expressions. When a “target” cartoon-like face was unilaterally projected, right-hemisphere superiority in face recognition accuracy was observed whether the “test” emotional stimuli were imagery faces or verbal labels. But when two different target faces were bilaterally presented simultaneously (i. e., one face to the right hemisphere and the other to the left hemisphere), right-hemisphere superiority was obtained only when the test stimuli were emotional labels. These results were predicted and interpreted in terms of the inter ruption effect of verbal processing on visual processing in the left hemisphere and of the interference and collaboration effects between two hemispheres on processing of differentiated emotional codes of facial expressions.