The role of attention in working memory

Attention is usually defined as the ability to select a limited amount of information from the abundance that we are continuously faced with, and short-term memory is often described as a temporary storage for this selected information. However, this description does not do justice to the complexities of the interplay between attention and short-term memory. This thesis explores how attention acts in and on short-term memory. It describes how attentionally selected information flows into short-term memory, and finds that encoding of several items can occur in parallel. It also demonstrates that encoding can occur in a serial fashion too, with behaviourally relevant items being selected and encoded first, and other items second. This thesis not only investigates the initial allocation of these resources during encoding, but also the re-allocation of short-term memory resources during eye movements. Specifically, it fails to replicate the finding that resources are re-allocated to saccade targets, but it does find that the location of items is stored at a higher precision than items’ other features are. Finally, this thesis describes how cancellation tasks (multi-target visual search tasks in which participants have to find and cross out targets among distractors) can be used to measure spatial attention and short-term memory in healthy adults and patient groups. Data is presented to show that cancellation performance can potentially be improved in subtle ways in stroke patients with hemispatial neglect syndrome, using the noradrenergic agonist guanfacine. In sum, attention acts as a gateway to and (re-)allocator of shortterm memory resources, and is an important target for pharmacological interventions in sensitive groups.