The role of the occipital cortex in capacity limits and precision of visual working memory

Amanda van Lamsweerde, Jeffrey Johnson
Journal of Vision 2015, 15 (12): 661
Several lines of evidence suggest a role for the occipital cortex in the storage of information in working memory (WM). For example, single pulse TMS to retinotopic visual cortex reduces shape change detection performance, but only during the time period when performance is sensitive to masking (van de Ven et al., 2012). Furthermore, although BOLD response in the occipital cortex is elevated during encoding but not maintenance, features such as color, orientation, or motion of remembered stimuli can be decoded from the occipital cortex by analyzing patterns of activity during WM maintenance (Emrich et al., 2013; Harrison & Tong, 2009; Serences et al., 2009). Furthermore, pattern classifier sensitivity is correlated with the precision of representations, but not capacity (Emrich et al., 2013). This suggests that the visual cortex may serve a storage function in WM and that visual cortex activity may determine the precision of WM representations. To test this hypothesis, single pulse TMS was applied to visual cortex at 0, 100, or 200ms after the offset of the memory stimulus. TMS-related changes in the capacity and precision of WM representations, as well as the likelihood of mis-binding objects to locations (swap errors), were analyzed. Occipital simulation decreased capacity and swap errors, and produced a small, non-significant increase in precision when applied immediately at stimulus offset, but not when applied 100 or 200ms later. Preliminary analysis of data from a follow-up experiment (n=5) revealed no change in capacity or precision when arrhythmic trains of high-frequency rTMS were applied to the occipital cortex either 125ms or 575ms after stimulus offset. This suggests that the occipital cortex contributes to VWM capacity, but the quality of representations may be specifically dependent on the number of items encoded into VWM; furthermore, occipital-based representations may not be vulnerable to disruption after initial encoding. Meeting abstract presented at VSS 2015.

Full Text Links

Find Full Text Links for this Article


You are not logged in. Sign Up or Log In to join the discussion.

Related Papers

Remove bar
Read by QxMD icon Read

Save your favorite articles in one place with a free QxMD account.


Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"