Abstract
Several theories posit that visual perception and visual working memory depend on a common selective mechanism—visual attention—that operates over the representation of currently visible objects and previously visible objects. Competing accounts hold that selective maintenance in working memory is dissociable from the locus of visual attention. Here, we tested of the role of visual attention in the maintenance of object locations in spatial working memory (SPWM). Relative to previous studies on this topic, the present method provided a more direct measure of spatial memory, allowed for a continuous estimate of memory precision, and manipulated attention in manner that did not require an additional discrimination task, significantly simplifying inferences regarding the role of visual attention. In the memory-only condition, participants could keep attention focused covertly on a remembered location during retention of that location. Participants maintained central fixation as a memory dot was presented briefly. After a retention interval, participants executed a saccade to the remembered location and pressed a button to report fixation of that location. Memory precision was calculated as the difference between fixation location and memory location. The dual-task condition was identical to the memory-only condition, except, during the retention interval, participants executed a saccade to a peripheral distractor box and back to the center. Because visual attention cannot be maintained at one location as a saccade is planned and executed to a different location, visual attention could not have been maintained continuously on the memory location during the retention interval. The addition of the saccade task produced no observable decrement in the precision of SPWM, despite sufficient power to detect a difference in accuracy of less than 0.05° of visual angle. Precise memory for location is not necessarily dependent on the allocation of visual attention, calling into question a direct, functional relationship between SPWM and attention.
Meeting abstract presented at VSS 2013