Theta burst stimulation of the visual cortex does not alter contrast sensitivity under optically induced blur
- 1School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China
- 2Centre for Eye & Vision Research, Hong Kong Science Park, Hong Kong SAR, China
- 3School of Optometry and Vision Science, University of Waterloo, Canada
Abstract
This study investigated whether a single session of repetitive transcranial magnetic stimulation (TMS), specifically theta burst stimulation (TBS), acutely modulates visual function under conditions of induced optical defocus. Twelve adults with normal or corrected-to-normal vision participated in a pre-registered, within-subject, double-blind, sham-controlled study. Participants first adapted to an experimentally induced + 1.50D optical blur for 10 minutes. Following this, stimulation was applied to the primary visual cortex according to a pre-randomised allocation. Stimulation consisted of continuous TBS (cTBS), intermittent TBS (iTBS), or sham stimulation, with each condition applied to all participants over separate visits. Visual acuity (VA) and contrast discrimination thresholds were measured under the induced blur condition immediately before and after stimulation. Repeated measures ANOVA revealed no significant interaction between stimulation condition and time for either contrast discrimination threshold (F(2,22) = 0.03, p = 0.96, partial ηp² = 0.003) or VA (F(2,22) = 0.12, p = 0.88, partial ηp² = 0.011). Although a significant main effect of time was observed for VA (F(1,11) = 6.30, p = 0.029, partial ηp² = 0.364), reflecting an improvement across all conditions, there were no differential effects attributable to active cTBS or iTBS compared to sham. Consequently, a single session of TBS applied to the visual cortex did not result in a measurable modulation of visual performance under acute optical defocus in adults with typical vision. Rapid homeostatic mechanisms activated during short-term blur adaptation may reduce the susceptibility of the visual cortex to the acute effects of TBS.
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BibTeX
@article{wong2026theta,
title = {{Theta burst stimulation of the visual cortex does not alter contrast sensitivity under optically induced blur}},
author = {Crystal Suei Cheng Wong and Ken Wei Sheng Tan and Tingni Li and Linden Gaultney and Benjamin Thompson and Tsz Wing Leung and Adela So Yun Park},
journal = {PLOS One},
year = {2026},
month = sep,
doi = {10.1371/journal.pone.0341942},
url = {https://doi.org/10.1371/journal.pone.0341942},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Theta burst stimulation of the visual cortex does not alter contrast sensitivity under optically induced blur
AU - Crystal Suei Cheng Wong
AU - Ken Wei Sheng Tan
AU - Tingni Li
AU - Linden Gaultney
AU - Benjamin Thompson
AU - Tsz Wing Leung
AU - Adela So Yun Park
PY - 2026
DA - 2026/09/01
JO - PLOS One
DO - 10.1371/journal.pone.0341942
UR - https://doi.org/10.1371/journal.pone.0341942
AB - This study investigated whether a single session of repetitive transcranial magnetic stimulation (TMS), specifically theta burst stimulation (TBS), acutely modulates visual function under conditions of induced optical defocus. Twelve adults with normal or corrected-to-normal vision participated in a pre-registered, within-subject, double-blind, sham-controlled study. Participants first adapted to an experimentally induced + 1.50D optical blur for 10 minutes. Following this, stimulation was applied to the primary visual cortex according to a pre-randomised allocation. Stimulation consisted of continuous TBS (cTBS), intermittent TBS (iTBS), or sham stimulation, with each condition applied to all participants over separate visits. Visual acuity (VA) and contrast discrimination thresholds were measured under the induced blur condition immediately before and after stimulation. Repeated measures ANOVA revealed no significant interaction between stimulation condition and time for either contrast discrimination threshold (F(2,22) = 0.03, p = 0.96, partial ηp² = 0.003) or VA (F(2,22) = 0.12, p = 0.88, partial ηp² = 0.011). Although a significant main effect of time was observed for VA (F(1,11) = 6.30, p = 0.029, partial ηp² = 0.364), reflecting an improvement across all conditions, there were no differential effects attributable to active cTBS or iTBS compared to sham. Consequently, a single session of TBS applied to the visual cortex did not result in a measurable modulation of visual performance under acute optical defocus in adults with typical vision. Rapid homeostatic mechanisms activated during short-term blur adaptation may reduce the susceptibility of the visual cortex to the acute effects of TBS.
SN - 1932-6203
ER -