People with schizophrenia (SZ) exhibit visual processing abnormalities that affect their daily functioning and remediating these deficits might help to improve functioning. Transcranial direct current stimulation (tDCS) is a potential tool for perceptual enhancement for this purpose, though there are no reports of tDCS applied to visual cortex in SZ. In a within-subject, crossover design, we evaluated the effects of tDCS on visual processing in 27 SZ. All patients received anodal, cathodal, or sham stimulation over the central occipital region in 3 visits separated by 1 week. In each visit, a backward masking task and an electroencephalography measure of visual neuroplasticity were administered after tDCS. Neuroplasticity was assessed with visual evoked potentials before and after tetanizing visual high-frequency stimulation. Masking performance was significantly poorer in the anodal and cathodal conditions compared with sham. Both anodal and cathodal stimulation increased the amplitude of P1 but did not change the plasticity index. We found significant plasticity effects of tDCS for only one waveform for one stimulation condition (P2 for anodal tDCS) which did not survive correction for multiple comparisons. The reason for the lack of tDCS stimulation effects on plasticity may be because tDCS was not delivered simultaneously with the tetanizing visual stimulus. The present findings emphasize the need for more research on the relevant parameters for stimulation of visual processing regions in clinical populations.
|Number of pages||8|
|Journal||Clinical EEG and Neuroscience|
|State||Published - 1 Nov 2020|
Bibliographical noteFunding Information:
The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This study was supported by a Young Investigator grant from the Brain and Behavior Research Foundation (PI: C. Jahshan), NIMH grant MH110470 (PI: M.F. Green), and in part by the VISN 22 Mental Illness Research, Education, and Clinical Center (Director: S.R. Marder), and the Research Enhancement Award Program on Enhancing Community Integration for Homeless Veterans (Director: M.F. Green). The contents do not represent the views of the U.S. Department of Veterans Affairs or the United States Government.
© EEG and Clinical Neuroscience Society (ECNS) 2020.
- visual plasticity