Reallocation of visual attention.

Attentional movement time was investigated within and across hemifields in a discrimination task in which retinal acuity was controlled. Ss discriminated targets in a two-alternative, forced-choice latency paradigm. In Experiments 1-3, costs were mediated by distance, even though it was varied independently of acuity. In Experiments 4 and 7, with distance held constant, costs were equivalent for crossing the vertical and horizontal meridians and for crossing 1 and 2 meridians. However, crossing 1 meridian produced costs that were less than the costs for shifts to unexpected locations in the same quadrant, partially replicating the inhibitory aftereffect of Tassinari, Aglioti,Chelazzi,Marzi,and Berlucchi (1987). An explanation based on a combination of analog movement (Tsal, 1983) and attentional distribution (Downing & Pinker, 1985; Hughes & Zimba, 1987; Tassinari et al., 1987) models was discussed.