Abstract
Introduction: Perceptual aberrations are a defining feature of psychotic psychopathology. In schizophrenia, perceptions are poorly shaped by visual context which may result from weak neural adaptation. Binocular rivalry paradigms have revealed people with schizophrenia and their biological relatives to have slowed rates of perceptual switches which is consistent with weak visual adaptation. We have shown that schizophrenia is also associated with slowed resting state alpha rhythms which can be interpreted as a reduced rate of temporal sampling. Because the frequency of the alpha rhythm has been associated with the rate of perceptual switches during binocular rivalry, we sought to determine whether the pace of alpha cycling predicted binocular rivalry switch rate in a sample of individuals with psychotic psychopathology and their biological relatives. Methods: We studied forty-two individuals from the samples of interest and healthy control participants who underwent a magneto-encephalography (MEG) session during which we administered a binocular rivalry task and collected eyes-closed rest and eyes-open fixation data. The two rivalry stimuli were frequency tagged to capture neural dynamics related to perceptual switches. We computed Individual alpha peak frequency (IAPF) for each participant as the greatest spectral power observed in the alpha range (7-13 Hz) for sensors over posterior brain regions. Results: Individuals with psychotic psychopathology exhibited waxing and waning of power in the frequency tags that largely coincided with the timing of reported perceptual switches. Across all three groups, lower IAPF during eyes-closed rest was associated with slower switch rates (r=0.469, p=.0052), while IAPF during eyes-open fixation failed to be related to switch rates (r=0.213, p=.22). The strength of the associations were reduced (though in the same direction) for the psychotic psychopathology group alone, contrary to our hypotheses. Conclusion: Perceptual cycles as reflected in the alpha rhythm are related to the rate of perceptual switches during binocular rivalry.