Fearful face recognition in schizophrenia: an electrophysiological study

Electrophysiological Studies of Reception of Facial Communication in Autism Spectrum Disorder and Schizophrenia

Autism spectrum disorder (ASD) and schizophrenia spectrum disorders (SZ) are characterized by difficulty with social cognition and atypical reception of facial communication - a key area in the Research Domain Criteria framework. To identify areas of overlap and dissociation between ASD and SZ, we review studies of event-related potentials (ERP) to faces across ASD and SZ populations, focusing on ERPs implicated in social perception: P100, N170, N250, and P300. There were many inconsistent findings across studies; however, replication was strongest for delayed N170 latency in ASD and attenuated N170 amplitude in SZ. These results highlight the challenges of replicating research findings in heterogeneous clinical populations and the need for transdiagnostic research that continuously quantifies behavior and neural activity across neurodevelopmental disorders.

A combined stimuli presentation for assessing facial emotion related N170, N250 and visual mismatch negativity in neuropsychiatric disorders

Event-related potential (ERP) is a useful approach to assess the neurophysiological correlates of facial emotion processing. Previous studies examined the facial emotion recognition (FER) related ERPs (N170, N250, visual MisMatch Negativity) individually using ERP specific paradigms. This approach can be time-consuming and may not resemble real-life scenarios where an individual must process multiple stimuli simultaneously. The aim of the study was to assess the utility of a combined paradigm when compared to individual paradigms to measure N170, N250 and visual MisMatch Negativity (vMMN) in healthy controls (HC), utilizing emotion stimuli standardized in the Indian population. Further, the combined paradigm was examined in patients with schizophrenia (SCZ) to detect the differences in ERPs compared to HC. Within paradigms, ERPs showed higher amplitudes for emotion compared to neutral stimuli suggesting that the paradigms were able to detect valence associated with emotional stimuli. The combined paradigm was able to elicit decipherable peaks of N170, N250 and vMMN similar to individual paradigms. ERP data quality as assessed by analytic Standardized Measurement Error (aSME) showed a satisfactory aggregate score of above 2 for all the three paradigms. Combined paradigm approaches to record ERPs in neuropsychiatric conditions has the advantage of reducing the time required for task administration, avoiding practice effects, better subject cooperation and participation.

Central nervous activity during implicit processing of emotional face expressions in fibromyalgia syndrome

OBJECTIVE

Fibromyalgia syndrome (FMS) is characterized by chronic widespread pain accompanied by symptoms like fatigue, insomnia, depression, anxiety and cognitive impairments. In addition to central nervous pain sensitization, emotional dysregulation may be involved in FMS pathogenesis. This study investigated central nervous correlates of affective and attentional processing in FMS using an implicit task.

METHODS

Event-related potentials (ERPs) of the EEG were recorded in 25 FMS patients and 37 healthy controls while they had to name the frame color of pictures displaying emotional expressions (angry, painful, happy, neutral). The actual picture had to be ingored. Symptoms of pain, depression and anxiety were also assessed.

RESULTS

Patients exhibited smaller P2 and late positive potential (LPP) amplitudes, and a greater N250 amplitude, than controls. The N250 amplitude varied according to the emotional expressions displayed in patients, but not in controls. No group differences arose for the P1 or N170 amplitudes. Patients had longer reaction times and made more errors on the task; task performance was more closely related to pain severity than to other symptoms.

CONCLUSION

The reduced P2 and LPP amplitudes indicate deficient short-term mobilization of attentional resources and sustained attention in FMS; the greater N250 amplitude may reflect greater engagement in the decoding of complex facial features, which is necessary to compensate for attentional impairments. Affective modulation of the N250 suggests that the neural mechanisms underlying complex visual processes are particularly susceptible to emotional influences in FMS. The behavioral data confirm attentional deficits in the disorder and implicate clinical pain therein.

Altered P3a Modulations to Emotional Faces in Male Patients With Chronic Schizophrenia

Existing evidence suggests that patients with schizophrenia may have a deficit in processing facial expressions. However, the neural basis of this processing deficit remains unclear. A total of 20 men diagnosed with chronic schizophrenia and 13 age- and sex-matched controls participated in the study. We investigated visual N170 and P3a components evoked in response to fearful, happy, and sad faces during an emotion discrimination task. Compared with control subjects, patients showed significantly smaller N170 amplitudes bilaterally (P = .04). We found no significant main effect of emotion of the presented faces (fearful, happy, or sad) on N170 amplitude. Patients showed significantly smaller P3a amplitudes in response to fearful (P = .01) and happy (P = .02) faces, but no significant between-group differences were observed for sad faces (P = .22). Moreover, we found no significant P3a modulation effect in response to emotional faces in patients with schizophrenia. Our results suggest that altered P3a modulations to emotional faces may be associated with emotion recognition deficits in patients with schizophrenia.

What Do You Have in Mind? Measures to Assess Mental State Reasoning in Neuropsychiatric Populations

Social interaction is closely associated with both functional capacity and well-being. Previous research has not only revealed evidence of social dysfunction in individuals with a wide range of psychiatric and neurological disorders but also generated an abundance of potential measures for assessing social cognition. This review explores the most popular measures used within neuropsychiatric populations to investigate the ability to recognize or reason about the mental states of others. Measures are also critically analyzed in terms of strengths and limitations to aid task selection in future clinical studies. The most frequently applied assessment tools use verbal, visual or audiovisual forms of presentation and assess recognition of mental states from facial features, self-rated empathy, the understanding of other's cognitive mental states such as beliefs and intentions, or the ability to combine knowledge of other's thoughts and emotions in order to understand subtle communications or socially inappropriate behavior. Key weaknesses of previous research include limited investigation of relationships with clinical symptoms, and underutilization of measures of everyday social functioning that offer a useful counterpart to traditional "lab" tasks. Future studies should aim to carefully select measures not only based on the range of skills to be assessed but also taking into account potential difficulties with interpretation and the need to gain insight into the application of social cognitive skills as well as ability per se. Some of the best measures include those with well-matched control trials (e.g., Yoni Task) or those that restrict the influence of verbal deficits (e.g., intentions comic strip task), elicit spontaneous mentalizing (e.g., Animations Task), and possess greater ecological validity (e.g., Movie for the Assessment of Social Cognition). Social cognitive research within psychiatric populations will be further enhanced through the development of more closely matched control tasks, and the exploration of relationships between task performance, medication, strategy use, and broader emotional and motor functions.

Neutral face and complex object neurophysiological processing deficits in long-term schizophrenia and in first hospitalized schizophrenia-spectrum individuals

BACKGROUND

Face processing is impaired in long-term schizophrenia as indexed by a reduced face-related N170 event-related potential (ERP) that corresponds with volumetric decreases in right fusiform gyrus. Impairment in face processing may constitute an object-specific deficit in schizophrenia that relates to social impairment and misattribution of social signs in the disease, or the face deficit may be part of a more general deficit in complex visual processing. Further, it is not clear the degree to which face and complex object processing deficits are present early in disease course. To that end, the current study investigated face- and object-elicited N170 in long-term schizophrenia and the first hospitalized schizophrenia-spectrum.

METHODS

ERPs were collected from 32 long-term schizophrenia patients and 32 matched controls, and from 31 first hospitalization patients and 31 matched controls. Subjects detected rarely presented butterflies among non-target neutral faces and automobiles.

RESULTS

For both patient groups, the N170s to all stimuli were significantly attenuated. Despite this overall reduction, the increase in N170 amplitude to faces was intact in both patient samples. Symptoms were not correlated with N170 amplitude or latency to faces.

CONCLUSIONS

Information processing of complex stimuli is fundamentally impaired in schizophrenia, as reflected in attenuated N170 ERPs in both first hospitalized and long-term patients. This suggests the presence of low-level visual complex object processing deficits near disease onset that persist with disease course.

Impairments of emotional face processing in schizophrenia patients: Evidence from P100, N170 and P300 ERP components in a sample of auditory hallucinators

Patients with schizophrenia show impaired face and emotional expression processing that may be due to early perceptual deficits or late impairments in higher-order emotional facial recognition. This study examined event-related potentials (ERPs) in 23 patients with schizophrenia who experience auditory hallucinations and 19 healthy controls. EEG activity was recorded from 32 scalp sites positioned according to the 10-10 placement system. Linked left and right electrodes at the mastoids served as the reference. The P100, N170 and P300 were measured during an emotional facial identification task, which included neutral, joyful, sad, angry and fearful facial expressions and non-face stimuli (chairs). P100 was measured at O_1/2 and P_7/8. N170 was measured at P_7/8. P300 was measured at P_z. Patients with schizophrenia were slower at identifying all facial expressions, including neutral ones. They also showed less positive P100 amplitude to sad, angry and fearful facial expressions. N170 amplitudes were smaller in patients in response to neutral, joyful, sad, angry, and fearful facial expression. Patients showed less positive P300 mean amplitudes to all facial expressions, including neutral ones. Within-group comparisons showed that patients exhibited a different pattern of ERP modulation across facial expressions than controls for P100 and N170, but not for P300. Our findings are compatible with the idea that behavioural and electrophysiological face-processing deficits in schizophrenia arise from early-stage deficits in visual processing.

Considerations in biomarker development for neurodevelopmental disorders

PURPOSE OF REVIEW

Despite significant progress in recognizing the biological bases of autism spectrum disorder, diagnosis and treatment rely primarily on subjective evaluation of behavior. This review highlights the challenges unique to neurodevelopmental disorders that have limited biomarker development.

RECENT FINDINGS

The field of neurodevelopmental disorders requires objective quantification of biological processes to enable designation of subgroups likely to benefit from specific treatments, index diagnostic status/risk, demonstrate engagement of targeted systems, and provide more rapid assessment of change than traditional clinical observation and caregiver report measures.

SUMMARY

Useful biomarkers for neurodevelopmental disorders must be reliable across development, evident at the individual level, and specific to a unit of analysis, be it diagnostic status or functional process. The ultimate value of biomarkers for neurodevelopmental disorders will relate to their ease of use, cost, scalability, sensitivity, and methodological objectivity.

Functional and clinical insights from neuroimaging studies in childhood-onset schizophrenia

Childhood-onset schizophrenia is a rare pediatric onset psychiatric disorder continuous with and typically more severe than its adult counterpart. Neuroimaging research conducted on this population has revealed similarly severe neural abnormalities. When taken as a whole, neuroimaging research in this population shows generally decreased cortical gray matter coupled with white matter connectivity abnormalities, suggesting an anatomical basis for deficits in executive function. Subcortical abnormalities are pronounced in limbic structures, where volumetric deficits are likely related to social skill deficits, and cerebellar deficits that have been correlated to cognitive abnormalities. Structures relevant to motor processing also show a significant alteration, with volumetric increase in basal ganglia structures likely due to antipsychotic administration. Neuroimaging of this disorder shows an important clinical image of exaggerated cortical loss, altered white matter connectivity, and differences in structural development of subcortical areas during the course of development and provides important background to the disease state.

Elementary sensory deficits in schizophrenia indexed by impaired visual mismatch negativity

INTRODUCTION

Mismatch negativity (MMN) is an automatic brain response to unexpected events. It represents a prediction error (PE) response, reflecting the difference between the sensory input and predictions. While deficits in auditory MMN are well known in schizophrenia, only few studies investigated impairments in predictive visual processing in schizophrenia. These studies used complex stimuli such as motion direction and emotional facial expressions. Here we studied whether automatic predictive processing of elementary features such as orientation is also impaired in schizophrenia.

METHODS

Altogether 28 patients with schizophrenia and 27 healthy controls matched in age, gender, and education participated in the study. EEG was recorded using 128 channels in the two experimental blocks. Using an oddball paradigm, horizontal stripes of Gabor patches were presented as frequent standards and vertical stripes as rare deviants in one block. Stimulus probabilities were swapped in the other block. Mismatch responses were obtained by subtracting responses to standard from those to deviant stimuli.

RESULTS

We found significant mismatch responses in healthy controls but not in patients in the prefrontal and occipital-parietal regions in the 90-200ms interval. Furthermore patients showed significantly decreased deviant minus standard difference waveforms relative to controls in the same regions with moderate to large effect sizes.

CONCLUSIONS

Our findings demonstrate that predictive processing of unattended low-level visual features such as orientation is impaired in schizophrenia. Our results complement reports of sensory deficits found in tasks requiring attentive processing and suggest that deficits are present in automatic visual sensory processes putatively mediated by glutamatergic functioning.

Meta-analysis of face processing event-related potentials in schizophrenia

BACKGROUND

Schizophrenia is associated with impaired face processing. N170 and N250 are two event-related potentials that have been studied in relation to face processing in schizophrenia, but the results have been mixed. The aim of this article was to conduct a meta-analysis of N170 and N250 in schizophrenia to evaluate trends and resolve the inconsistencies.

METHODS

Twenty-one studies of N170 (n = 438 schizophrenia patients, n = 418 control subjects) and six studies of N250 (n = 149 schizophrenia patients, n = 151 control subjects) were evaluated. Hedges' g was calculated for each study, and the overall weighted mean effect size (ES) was calculated for N170 and N250. Homogeneity of the ES distributions, potential publication bias, and impact of potential moderators were also assessed.

RESULTS

The amplitude of both N170 and N250 to face stimuli was smaller in patients than control subjects (N170 ES = .64; N250 ES = .49; ps < .001). The distributions of the ES were homogeneous (ps > .90), and there was no indication of a publication bias. We found no significant effect of task requirements regarding judgments of the face stimuli. Moreover, we found no significant difference between the ES for N170 and N250.

CONCLUSIONS

Though findings of individual studies have been mixed, the results of the meta-analysis strongly support disruption of N170 and N250 in schizophrenia. The comparable effect sizes across the two waveforms suggest that the well-established behavioral deficit in face emotion processing is mirrored in an underlying neural impairment for processing faces.

The N170 and face perception in psychiatric and neurological disorders: A systematic review

OBJECTIVE

To systematically evaluate evidence for configural and affective face processing abnormalities as measured by the N170 and Vertex Positive Potential (VPP) event-related potential components, and analogous M170 magnetoencephalography (MEG) component, in neurological and psychiatric disorders.

METHODS

1251 unique articles were identified using PsychINFO and PubMed databases. Sixty-seven studies were selected for review, which employed various tasks to measure the N170, M170 or VPP; the 13 neurological/psychiatric conditions were Attention-Deficit Hyperactivity Disorder (ADHD), Alcohol Dependence, Alzheimer's Disease, Autism Spectrum Disorders (ASDs), Bipolar Disorder, Bulimia Nervosa, Fibromyalgia, Huntington's Disease, Major Depressive Disorder, Parkinson's Disease, Prosopagnosia, Schizophrenia and Social Phobia.

RESULTS

Smaller N170 and VPP amplitudes to faces compared to healthy controls were consistently reported in Schizophrenia but not in ASDs. In Schizophrenia N170 and VPP measures were not correlated with clinical symptoms. Findings from other disorders were highly inconsistent; however, reported group differences were almost always smaller amplitudes or slower latencies to emotional faces in disordered groups regardless of diagnosis.

CONCLUSIONS

Results suggest that N170/VPP abnormalities index non-specific facial affect processing dysfunction in these neurological and psychiatric conditions, reflecting social impairments being broadly characteristic of these groups.

SIGNIFICANCE

The N170 and analogous components hold promise as diagnostic and treatment monitoring biomarkers for social dysfunction.

A multimodal emotion detection system during human-robot interaction

In this paper, a multimodal user-emotion detection system for social robots is presented. This system is intended to be used during human–robot interaction, and it is integrated as part of the overall interaction system of the robot: the Robotics Dialog System (RDS). Two modes are used to detect emotions: the voice and face expression analysis. In order to analyze the voice of the user, a new component has been developed: Gender and Emotion Voice Analysis (GEVA), which is written using the Chuck language. For emotion detection in facial expressions, the system, Gender and Emotion Facial Analysis (GEFA), has been also developed. This last system integrates two third-party solutions: Sophisticated High-speed Object Recognition Engine (SHORE) and Computer Expression Recognition Toolbox (CERT). Once these new components (GEVA and GEFA) give their results, a decision rule is applied in order to combine the information given by both of them. The result of this rule, the detected emotion, is integrated into the dialog system through communicative acts. Hence, each communicative act gives, among other things, the detected emotion of the user to the RDS so it can adapt its strategy in order to get a greater satisfaction degree during the human–robot dialog. Each of the new components, GEVA and GEFA, can also be used individually. Moreover, they are integrated with the robotic control platform ROS (Robot Operating System). Several experiments with real users were performed to determine the accuracy of each component and to set the final decision rule. The results obtained from applying this decision rule in these experiments show a high success rate in automatic user emotion recognition, improving the results given by the two information channels (audio and visual) separately.