Attentional tracking drives contralateral delay activity in a dual working memory and object tracking task

Poster Session F - Tuesday, April 16, 2024, 8:00 – 10:00 am EDT, Sheraton Hall ABC

Piotr Styrkowiec^1,2 (pstyrkowiec@uchicago.edu), William Ngiam¹, William Epstein¹, Ron Gneezy¹, Edward Awh¹, Edward Vogel¹; ¹University of Chicago, USA, ²University of Wroclaw, Poland

Recent work suggests visual working memory (VWM) capacity may be limited by the assignment of spatiotemporal pointers to individuated objects, not stimulus information exactly (Thyer et al., 2022). We examined the contralateral delay activity (CDA), an event-related potential thought to track VWM load. The CDA amplitude has been shown to reflect the number of attended targets during multiple-object tracking (Drew and Vogel, 2008), but also the number of to-be-remembered items (i.e. colors; Vogel and Machizawa, 2004). We developed a novel dual-task paradigm to directly contrast the effects of attentional tracking load and stimulus content load on the CDA. Participants tracked either one or two moving discs (attentional tracking load), with either two or four total colors displayed within the discs (working memory load). Participants completed two conditions: a ‘tracking only’ condition (similar to multiple-object tracking), where participants ignore the colors and maintain attention on the moving discs, and a ‘tracking plus memory’ condition (similar to multiple-identity tracking), where participants tracked the discs as well as encoded the shown colors. The critical question was whether CDA amplitude would be determined by the number of individuated items tracked, or by the number of distinct colors associated with the currently tracked items. CDA amplitude was largely determined by the number of items tracked (attentional tracking load), with no discernible effect of the number of colors per tracked item. These findings suggest the CDA reflects the number of spatiotemporal pointers for moving objects, not the identity of those objects.

Topic Area: ATTENTION: Other