Grounding Verbal Working Memory: The Case of Serial Order

The maintenance of serial order in verbal working memory (WM) is a major unsolved puzzle in cognitive science. Here we review a series of studies showing that serial order in verbal WM closely interacts with spatial processing. Accordingly, we outline the "mental whiteboard hypothesis," which postulates that serial order in verbal WM is grounded in the spatial attention system. Specifically, serial context in verbal WM is provided by binding the memoranda to coordinates within an internal, spatially defined system within which (internal) spatial attention is at play to the purpose of searching for and retrieving information. Challenges and opportunities to be considered in future studies are discussed.