Abstract
Debates about spatial attention often center on its nature (e.g., one or multiple foci) rather than its heterogeneity (e.g., one or multiple types). Many studies have demonstrated that spatial attention is involved in visual search, visual working memory, and is modulated by perceptual salience, goals, and implicit learning. Yet it is unclear whether the same system is involved in these tasks and processes. To better understand the fractionation of spatial attention, we examined the influence of visual working memory on implicitly learned attention. If the same type of spatial attention underlies spatial working memory and implicit learning, then increasing working memory load should interfere with implicitly guided attention. In three experiments, participants remembered a color array or dot locations in working memory. During the memory retention interval, they conducted a visual search task for a T target among L distractors. Unbeknownst to the participants, the T was more often found in certain locations than others. When working memory load was low, participants were faster finding the target when it was in the high-probability locations than low-probability locations, and this enhancement scaled with set size. Increasing working memory load delayed search RT. However, location probability learning was equally robust under high and low working memory load. In addition, learning acquired under low load transferred to search under high load, and vice versa. These findings indicate that the type of spatial attention involved in visual working memory is not crucial for location probability learning. Additional experiments showed that although probability cuing was insensitive to working memory load, it was task specific. We suggest that spatial attention is comprised of a "where" and a "how" system. Goal-driven attention affects where attention should be deployed, but implicit learning modulates how attention is allocated in a task.
Meeting abstract presented at VSS 2013