The brain at rest generates cycles of electrical activity that have been shown to be abnormal in people with schizophrenia. The alpha rhythm (~ 10 Hz) is the dominant resting state electrical cycle and each person has a propensity toward a particular frequency of oscillation for this rhythm. This individual alpha peak frequency (IAPF) is hypothesized to be central to visual perceptual processes and may have downstream influences on cognitive functions such as attention, working memory, or problem solving. In the current study we sought to determine whether IAPF was slower in schizophrenia, and whether lower IAPF predicted deficits in visual perception and cognition that are often observed in schizophrenia. Eyes-closed resting state EEG activity, visual attention, and global cognitive functioning were assessed in individuals with schizophrenia (N = 104) and a group of healthy controls (N = 101). Compared to controls, the schizophrenia group showed slower IAPF and was associated with poorer discrimination of visual targets and nontargets on a computerized attention task, as well as impaired global cognition measured using neuropsychological tests across groups. Notably, disruptions in visual attention fully mediated the relationship between IAPF and global cognition across groups. The current findings demonstrate that slower alpha oscillatory cycling accounts for global cognitive deficits in schizophrenia by way of impairments in perceptual discrimination measured during a visual attention task.
Bibliographical noteFunding Information:
This material is the result of work supported with resources and use of facilities at the VA Pittsburgh and VA Minneapolis Healthcare Systems. The research was supported by Merit Review Grants (#2I01CX000227) to Dr. Scott Sponheim from the Veterans Health Administration Clinical Science Research and Development Program. The contents of this article do not represent the views of the U.S. Department of Veterans Affairs or the United States Government. Additionally Dr. Ian S. Ramsay was supported by NIMH (K01MH117451) and Dr. Peter Lynn was supported by the Lynne and Andrew Redleaf Foundation (78129). The authors report no disclosures.
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