title: Finding the answer in space: the mental whiteboard hypothesis on serial order in working memory.
abstract: Various prominent models on serial order coding in working memory (WM) build on the notion that serial order is achieved by binding the various items to-be-maintained to fixed position markers. Despite being relatively successful in accounting for empirical observations and some recent neuro-imaging support, these models were largely formulated on theoretical grounds and few specifications have been provided with respect to the cognitive and/or neural nature of these position markers. Here we outline a hypothesis on a novel candidate mechanism to substantiate the notion of serial position markers. Specifically, we propose that serial order WM is grounded in the spatial attention system: (I) The position markers that provide multi-item WM with a serial context should be understood as coordinates within an internal, spatially defined system; (II) internal spatial attention is involved in searching through the resulting serial order representation; and (III) retrieval corresponds to selection by spatial attention. We sketch the available empirical support and discuss how the hypothesis may provide a parsimonious framework from which to understand a broad range of observations across behavioral, neural and neuropsychological domains. Finally, we pinpoint what we believe are major questions for future research inspired by the hypothesis.
authors.affiliation: Department of Experimental Psychology, Faculty of Psychology and Educational Sciences, Ghent University Ghent, Belgium.
authors.forename: Elger
authors.initials: E
authors.lastname: Abrahamse
authors.affiliation: Department of Experimental Psychology, Faculty of Psychology and Educational Sciences, Ghent University Ghent, Belgium.
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: van Dijck
authors.affiliation: Department of Psychology, Cognition and Behavior, University of Liège Ghent, Belgium ; Fund for Scientific Research FNRS Belgium.
authors.forename: Steve
authors.initials: S
authors.lastname: Majerus
authors.affiliation: Department of Experimental Psychology, Faculty of Psychology and Educational Sciences, Ghent University Ghent, Belgium.
authors.forename: Wim
authors.initials: W
authors.lastname: Fias
keywords: hypothesis; position marker; positional models; serial order; space; spatial attention; working memory