Neurophysiological Face Processing Deficits in Patients With Chronic Schizophrenia: An MEG Study

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Psychiatry

Background:

• Schizophrenia (SZ) is associated with facial recognition difficulties and reduced N170 visual evoked responses to faces.
• Previous studies lacked high spatial resolution neurophysiological evidence for face processing deficits in SZ.
• This study investigated M170 (magnetic counterpart of N170) activity in chronic SZ patients using magnetoencephalography (MEG).

Purpose of the Study:

• To determine if M170 deficits in schizophrenia are specific to face stimuli.
• To explore the neurophysiological underpinnings of face processing abnormalities in SZ.
• To correlate M170 responses with demographic and clinical factors in SZ.

Main Methods:

• Recorded whole-head MEG responses (M170) to faces and cars in 26 SZ patients and 26 healthy controls (HC).
• Analyzed global field power over temporal cortices and localized M170 sources using minimum-norm estimation (MNE).
• Performed correlational analyses between M170 responses and participant demographics/symptoms.

Main Results:

• M170 response to faces was significantly reduced in SZ patients compared to HC (p=0.01), but not to cars (p=0.55).
• MNE revealed M170 localized to the fusiform face area (FFA) in HC, but to other visual regions in SZ.
• Negative symptom severity in SZ correlated negatively with M170 power (rho=-0.47, p=0.01).

Conclusions:

• Schizophrenia is characterized by specific reductions in the M170 response to human faces.
• These face processing deficits in SZ are associated with the severity of negative symptoms.
• Functional face processing deficits may contribute to social cognition impairments observed in schizophrenia.