Abstract
Individual differences in working memory capacity (WMC) correlate with an ever-growing number of cognitive tasks. These individual differences are thought to predict performance because they tap into variation in executive attention. A little-explored question, however, is to what extent individual differences in WMC might account for performance in “lower level”, more perceptual tasks, where a requirement of attentional control may be less apparent (e.g., Allen, Beilock, & Shevell, VSS 2009). This study investigated whether individual differences in WMC are related to individual differences in perception of a bistable figure.
Participants viewed a Necker cube on a computer screen with a fixation cross at its center, and indicated when their percept alternated during several 3-min trials. Dominance duration (average elapsed time between a perceptual alternation) was measured under four conditions (Kornmeier, Hein, & Bach, 2009). In the passive condition (always completed first), participants were simply told to report their alternations. In the hold-unspecific condition, participants attempted to hold whichever percept was currently dominant. In the hold-specific condition, participants attempted to hold a specified percept. In the reverse condition, participants attempted to alternate their percept as often as possible. WMC was measured using the RSPAN task (Daneman & Carpenter, 1980).
WMC was positively correlated with dominance duration in the passive and hold-unspecific conditions, and negatively correlated with dominance duration in the reverse condition and for the non-specified percept in the hold-specific condition. These results are expected if individual differences in WMC are related to the ability to exert “top-down” attentional control to increase or decrease the dominance duration of a bistable figure. Moreover, results from the passive condition demonstrate the relation with WMC holds without any goal-directed task, suggesting a “lower-level” perceptual process; in addition, this result provides a possible mechanism for the often-reported individual differences in dominance duration for passively viewed bistable figures.
Supported by NIH grant EY-04802 to S.S. and NSF CAREER award DRL-0746970 to S.B.