Assessing the Effect of Early Visual Cortex Transcranial Magnetic Stimulation on Working Memory Consolidation

Abstract

Maintaining visual working memory (VWM) representations recruits a network of brain regions, including the frontal, posterior parietal, and occipital cortices; however, it is unclear to what extent the occipital cortex is engaged in VWM after sensory encoding is completed. Noninvasive brain stimulation data show that stimulation of this region can affect working memory (WM) during the early consolidation time period, but it remains unclear whether it does so by influencing the number of items that are stored or their precision. In this study, we investigated whether single-pulse transcranial magnetic stimulation (spTMS) to the occipital cortex during VWM consolidation affects the quantity or quality of VWM representations. In three experiments, we disrupted VWM consolidation with either a visual mask or spTMS to retinotopic early visual cortex. We found robust masking effects on the quantity of VWM representations up to 200 msec poststimulus offset and smaller, more variable effects on WM quality. Similarly, spTMS decreased the quantity of VWM representations, but only when it was applied immediately following stimulus offset. Like visual masks, spTMS also produced small and variable effects on WM precision. The disruptive effects of both masks and TMS were greatly reduced or entirely absent within 200 msec of stimulus offset. However, there was a reduction in swap rate across all time intervals, which may indicate a sustained role of the early visual cortex in maintaining spatial information.

Right hemisphere occipital rTMS impairs working memory in visualizers but not in verbalizers

“…Online single pulse occipital TMS may only bear a disruptive effect during high memory load 41 . Single pulses of TMS applied after onset of an array of stimuli reduced performance mainly by increasing the probability of guessing, consistent with affecting primarily the quantity (capacity) and not quality (precision) of stored information 42 .…”

Sensory Recruitment in Visual Short-Term Memory: A Systematic Review and Meta-Analysis of Sensory Visual Cortex Interference Using Transcranial Magnetic Stimulation

“…Our findings confirm the causal contribution of the sensory visual cortex in encoding of visual information in VSTM. In the six experiments described in the systematic review, all but one provided significant evidence that TMS during the encoding phase of VSTM can affect memory performance (Cattaneo et al, 2009;Koivisto et al, 2017;Rademaker et al, 2017;van Lamsweerde, & Johnson, 2017). In addition, the quantitative analysis of the studies included in the meta-analysis further supports the presence of an effect of TMS on sensory visual cortex during the encoding phase of VSTM.…”

“…TMS interference during encoding. The effects of TMS interference of the sensory visual cortex activity during the encoding phase of visual information was tested in six experiments, from five studies (Cattaneo, Vecchi, Pascual-Leone, & Silvanto, 2009;Koivisto, Harjuniemi, Railo, Salminen-Vaparanta, & Revonsuo, 2017;Rademaker, van de Ven, Tong, & Sack, 2017;van de Ven, Jacobs, & Sack, 2012;van Lamsweerde, & Johnson, 2017). As expected, the majority of these studies presented evidence supporting the involvement of the sensory visual cortex during VSTM encoding.…”

Sensory Recruitment in Visual Short-Term Memory: A Systematic Review and Meta-Analysis of Sensory Visual Cortex Interference Using Transcranial Magnetic Stimulation

“…TMS interference during encoding. The effects of TMS interference of the sensory visual cortex activity during the encoding phase of visual information was tested in six experiments, from five studies (Cattaneo et al, 2009;Koivisto et al,2017;Rademaker et al, 2017;van de Ven et al, 2012;van Lamsweerde, & Johnson, 2017). As expected, the majority of these studies presented evidence supporting the involvement of the sensory visual cortex during VSTM encoding.…”

“…TMS interference during maintenance. TMS was delivered during the maintenance phase of a VSTM task (i.e., more than 200 ms after stimulus onset) in 14 experiments from twelve different studies (Cattaneo et al, 2012;Jia et al, 2021;Malik et al, 2015;Rademaker et al, 2017;Saad, & Silvanto, 2013;Saad et al, 2015;Silvanto & Cattaneo, 2010;van de Ven et al, 2012;van Lamsweerde, & Johnson, 2017;Zokaei et al, 2014). As discussed in detail below, although the majority of these studies provide evidence supporting the sensory recruitment hypothesis, others either failed to find such evidence or their findings are more consistent with an interaction between perceptual and VSTM processes, as we suggest below.…”