Emotion-elicited gamma synchrony in patients with first-episode schizophrenia: a neural correlate of social cognition outcomes.
BACKGROUND
Schizophrenia may be understood as a disorder of neural synchrony. There is also increasing evidence that emotional and social cognitive impairments are central to this disorder. In patients with first-episode schizophrenia, we examined whether emotion perception is associated with disruptions to high-frequency (40 Hz) gamma synchrony and whether these disruptions predict self-regulatory adaptive compensations reflected in social cognitive behaviours.


METHODS
We obtained electroencephalography recordings from 28 patients with first-episode schizophrenia and matched healthy controls during perception of facial emotion under both conscious and nonconscious conditions. We extracted gamma-band synchrony from the electroencephalogram. We also used behavioural measures of emotion identification, emotional intelligence, negativity bias and social function, along with ratings of first-episode schizophrenia symptoms. We analyzed group differences and predicted social cognition to assess the potential contribution of medication.


RESULTS
Within 200 ms poststimulus, patients with first-episode schizophrenia showed alterations in gamma synchrony during both conscious and nonconscious emotion perception. Stimulus-locked synchrony was reduced in patients, particularly over the temporal cortex, whereas complementary enhancements in absolute gamma synchrony (independent of stimuli) were more distributed over temporal and left parieto-occipital regions. This pattern of altered synchrony predicted poor performance on each measure of social cognition among these patients. Medication dosage did not correlate significantly with either gamma synchrony or behavioural measures in this group.


CONCLUSIONS
Limitations to our study include the lack of comparison between medicated and unmedicated patients or between types of medication.


CONCLUSIONS
These findings suggest that disruptions in integrative processing of motivationally important stimuli show promise as a potential biological marker of social cognitive impairments, present from the first episode of schizophrenia, and their outcomes.
Williams
Leanne M
LM
Brain Dynamics Centre, Westmead Millennium Institute and Western Clinical School, University of Sydney, Westmead Hospital, Westmead NSW, Australia. lea_williams@wmi.usyd.edu.au
Whitford
Thomas J
TJ
Nagy
Marie
M
Flynn
Gary
G
Harris
Anthony W F
AW
Silverstein
Steven M
SM
Gordon
Evian
E
D014150:Antipsychotic Agents / Q000494:pharmacology; D001921:Brain / Q000503:physiopathology*; D016022:Case-Control Studies; D003071:Cognition / Q000502:physiology*; D003344:Cortical Synchronization / Q000187:drug effects / Q000523:psychology*; D004644:Emotions / Q000502:physiology*; D005149:Facial Expression; D005260:Female; D006801:Humans; D008297:Male; D010465:Perception / Q000502:physiology; D012559:Schizophrenia / Q000175:diagnosis / Q000188:drug therapy / Q000503:physiopathology*; D012565:Schizophrenic Psychology; D012919:Social Behavior; D055815:Young Adult
D014150:Antipsychotic Agents