ERP Study of Facial Emotional Expression and Gender Processing Abnormalities in Autism

• Published in: Applied psychophysiology and biofeedback Vol. 38; no. 3; p. 236
• Main Authors: Hinchen, Ashley, Sokhadze, Estate, Kong, Maiying, Sokhadze, Guela, Casanova, Manuel
• Format: Journal Article
• Language: English
• Published: Springer 01-09-2013
• Subjects: Autism; Enterprise resource planning
• ISSN: 1090-0586

The hallmark deficits of autism spectrum disorder (ASD) include disturbances of affective reactivity and the innate ability to perceive and appropriately respond to social cues, including emotional facial expressions. This study utilized event-related potential (ERP) recordings in a modification of a theory-of-mind (ToM) task that tests the ability to correctly deduce another individual's emotional state. Our ToM test used recognition of emotional facial expressions and gender categorization in children with ASD and in age-matched typical children (CNT). The goal of the study was to find the differences between the ASD (N = 19, mean 16.3 years) and CNT groups (N = 21, 14.9 years) by examining behavioral and event-related potential (ERP) correlates of processing emotional information from facial expressions in a ToM test. All participants were shown a face and were asked to identify either the gender or the emotion of the face in 4 different conditions. A 128 channel EEG was recorded from patients as they completed the tasks. The ERPs used were N170, P3a, and P3b at various topographies. The results showed the error rate in the gender condition was higher in the ASD as compared to controls (F = 9.12, p = 0.005). Comparing the conditions of gender versus anger/disgust emotion categorization, the ASD group committed more errors regardless of condition (F = 6.04, p = 0.02). ERP measures also yielded group differences: occipital N170 was more negative in ASD when identifying emotional faces (F = 5.66, p = 0.023). The N170 latency was prolonged in the ASD group (F = 7.54, p = 0.01). The ASD group had a larger frontal P3a as compared to controls in emotion differentiation task (F = 5.15, p = 0.03). In the emotion recognition conditions, centro-parietal P3b was larger in autism (F = 4.17, p = 0.049). These results indicate that more effort is required for an individual with autism to recognize emotion rather than gender from viewing a face. The measurement of ERPs along with behavioral responses provides confirmation that differences exist between how those with autism and those without process emotional faces. Abnormal processing of emotional stimuli may provide an explanation for some of the social and communicative deficits observed in autism. Keywords * Autism * Event-related potential * Facial emotion processing