Working memory storage is intrinsically domain specific.
A longstanding debate in working memory (WM) is whether information is maintained in a central, capacity-limited storage system or whether there are domain-specific stores for different modalities. This question is typically addressed by determining whether concurrent storage of 2 different memory arrays produces interference. Prior studies using this approach have shown at least some cost to maintaining 2 memory arrays that differed in perceptual modalities. However, it is not clear whether these WM costs resulted from competition for a central, capacity-limited store or from other potential sources of dual-task interference, such as task preparation and coordination, overlap in representational content (e.g., object vs. space based), or cognitive strategies (e.g., verbalization, chunking of the stimulus material in a higher order structure). In the present study we assess dual-task costs during the concurrent performance of a visuospatial WM task and an auditory object WM task when such sources of interference are minimized. The results show that performance of these 2 WM tasks are independent from each another, even at high WM load. Only when we introduced a common representational format (spatial information) to both WM tasks did dual-task performance begin to suffer. These results are inconsistent with the notion of a domain-independent storage system, and suggest instead that WM is constrained by multiple domain-specific stores and central executive processes. Evidently, there is nothing intrinsic about the functional architecture of the human mind that prevents it from storing 2 distinct representations in WM, as long as these representations do not overlap in any functional domain.
Department of Psychology, Vanderbilt University.
Daryl
D
Fougnie
Department of Psychology, Vanderbilt University.
Samir
S
Zughni
Department of Psychology, Vanderbilt University.
Douglass
D
Godwin
Department of Psychology, Vanderbilt University.
René
R
Marois
D000293:Adolescent; D000328:Adult; D001288:Attention; D005260:Female; D006801:Humans; D008297:Male; D008570:Memory, Short-Term; D010364:Pattern Recognition, Visual; D013028:Space Perception; D055815:Young Adult