Single Pulses of TMS to Visual Cortex Have Persistent Effects on Visual Working Memory

Poster Session B - Sunday, April 14, 2024, 8:00 – 10:00 am EDT, Sheraton Hall ABC

Chenlingxi Xu¹ (cxu5@nd.edu), Zengbo Xie², Jason Samaha³, Nathan Rose¹; ¹University of Notre Dame, ²Vanderbilt University, ³University of California, Santa Cruz

Neuroimaging studies of visual WM have identified that delay-period neural signals such as the N2pc ERP, frontal theta oscillations and hemispheric alpha asymmetry are correlated to performance (Schneider et al., 2018; Zickerick et al., 2021). However, the exact contribution of these neural components to WM behavior remains unclear. To assess their causal roles in WM, this study administered a two-item, double-retrocue WM task with single-pulses of TMS applied to a retinotopically-mapped region of participants’ left visual cortex during the delay periods while EEG was recorded. Single-pulse transcranial magnetic stimulation (spTMS) is a neurophysiology probe that can be used to “ping” the cortex and detect activation state of items in working memory (WM). Previous studies suggest that spTMS typically does not induce changes in brain activity or behavior that last beyond the stimulation period (Klomjai et al., 2015). Analyses suggested that spTMS had hemisphere-specific effects: WM performance was significantly better, and had larger improvements as a function of task difficulty (measured by angular difference between target and probe), on TMS-targeted (right-cued) trials than on control (left-cued) trials; following the first retrocue, TMS abolished the N2pc component on right-cued, but not left-cued trials; following the second retrocue, TMS selectively abolished hemispheric alpha asymmetry in the delay period on the TMS-targeted hemisphere. Collectively, the findings indicate carry-over effects of spTMS that have selective effects on lateralized neural and behavioral indices of performance. The current finding that visual cortex stimulation does affect visual working memory is consistent with the sensory recruitment hypothesis of WM.

Topic Area: EXECUTIVE PROCESSES: Working memory