Movement of attention across the visual field

Conducted 3 experiments to measure vocal RTs of 26 undergraduates for targets presented at 3 distances from fixation. The targets were preceded by a cue, and the time interval between the cue and the target (stimulus-onset asynchrony; SOA) was varied. For each peripheral distance, the RT function initially declined as SOA was increased and then reached asymptote. As the target was moved further from fixation, the SOA at which the function reached asymptote became longer. The asymptotic SOA values were taken as a measure of the time it takes attention to reach a given target. Comparisons of these values for the 3 peripheral distances permitted estimating the velocity of attention movements. These measurements suggest that when summoned by a peripheral cue, attention travels through space at a constant velocity of about 1|/8 msec. (12 ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved).