Discrete fixed-resolution representations in visual working memory.
Limits on the storage capacity of working memory significantly affect cognitive abilities in a wide range of domains, but the nature of these capacity limits has been elusive. Some researchers have proposed that working memory stores a limited set of discrete, fixed-resolution representations, whereas others have proposed that working memory consists of a pool of resources that can be allocated flexibly to provide either a small number of high-resolution representations or a large number of low-resolution representations. Here we resolve this controversy by providing independent measures of capacity and resolution. We show that, when presented with more than a few simple objects, human observers store a high-resolution representation of a subset of the objects and retain no information about the others. Memory resolution varied over a narrow range that cannot be explained in terms of a general resource pool but can be well explained by a small set of discrete, fixed-resolution representations.
Zhang
Weiwei
W
Department of Psychology, University of Iowa, Iowa City, Iowa 52242, USA. wwzhang@ucdavis.edu
Luck
Steven J
SJ
D000293:Adolescent; D000328:Adult; D003116:Color; D003463:Cues; D006801:Humans; D008570:Memory, Short-Term / Q000502:physiology*; D011939:Mental Recall / Q000502:physiology*; D008959:Models, Neurological; D010775:Photic Stimulation; D014796:Visual Perception / Q000502:physiology*