Eye movements follow the dynamic shifts of attention through serial order in verbal working memory

How are arbitrary sequences of verbal information retained and manipulated in working memory? Increasing evidence suggests that serial order in verbal WM is spatially coded and that spatial attention is involved in access and retrieval. Based on the idea that brain areas controlling spatial attention are also involved in oculomotor control, we used eye tracking to reveal how the spatial structure of serial order information is accessed in verbal working memory. In two experiments, participants memorized a sequence of auditory words in the correct order. While their eye movements were being measured, they named the memorized items in a self-determined order in Experiment 1 and in a cued order in Experiment 2. We tested the hypothesis that serial order in verbal working memory interacts with the spatial attention system whereby gaze patterns in visual space closely follow attentional shifts in the internal space of working memory. In both experiments, we found that the gaze shifts in visual space correlated with the spatial shifts of attention along the left-to-right one-dimensional mapping of serial order positions in verbal WM. These findings suggest that spatial attention is employed for dynamically searching through verbal WM and that eye movements reflect the spontaneous association of order and space even in the absence of visuospatial input.