Focal attention in visual search

Visual search operates in different modes assumed to reflect serial and par allel processing. The basis of this distinction is not yet clear. It is oft en assumed that serial search involves sequential shifts of focal attention across a scene and that no such shifts occur in parallel search. Direct me asurements of attention effects during search show that the focus of attent ion moves to the target (and away from non-targets) both in serial and para llel search. This suggests that the two search modes do not differ in their attentional load but perhaps in the way in which focal attention is direct ed to the target. (C) 1999 Elsevier Science Ltd. All rights reserved.