The focus of attention as observed in visual working memory tasks: making sense of competing claims

Recent behavioral and neuroscientific evidence speaks to the question of whether the human focus of attention is limited to a single item or can accommodate several items. This issue is fundamental to an understanding of the nature of human cognition and brain function. Here I review evidence from visual working memory tasks and suggest that it supports the concept of a focus of attention that can include several items at once as a core vehicle of working memory, regardless of the stimulus modality. One brain area in particular, the left intraparietal sulcus (IPS), seems critically important in the network underlying the focus of attention as a working memory storage mechanism. This view is reconciled with evidence previously taken to indicate that the focus of attention only includes a single item at a time, which is reinterpreted here.