Seeing fuzzy emotion: Low spatial frequency hinders the early integration of facial details in schizophrenia.
Laprevote, V., Oliva, A., Delerue, C., Thomas, P., & Boucart, M. (submitted)
CONTEXT: Understanding facial emotion is a key aspect of social interaction that is impaired in schizophrenia. One important mechanism of emotion recognition is the integration of visual information at various spatial scales. In this paper, we tested the extent to which patients with schizophrenia show a deficit in integrating low and high spatial frequency bands in rapid facial emotion recognition tasks. METHOD: Nineteen patients with schizophrenia and sixteen controls performed two emotion judgment tasks on low and high spatial frequency filtered faces, as well as on hybrid stimuli, combining two different faces in different spatial frequency bands. All stimuli were shown for 100 msec. Because hybrid faces show two different facial expressions, the selected emotion probes which spatial scale is preferentially perceived at an early stage of visual processing. RESULT: Whereas patients and controls performed better with high spatial frequency only images, patients exhibited a strong bias towards the low spatial frequency of hybrid stimuli in both emotion tasks. Controls, however, showed the expected bias towards high spatial frequency with hybrid stimuli. CONCLUSION: We propose that these results probe a high-order visual deficit in schizophrenia: whereas patients perceive small details in isolation, the early mechanism of integrating high-spatial frequency with low spatial frequency is impaired, contributing to their deficits in face and emotion processing.