Enhancing single-item recognition accuracy by cueing spatial locations in vision

With single-item visual displays, facilitating effects of foreknowledge of position have been shown in detection tasks with latency and with accuracy as the dependent variables, as well as in recognition tasks with latency as the dependent variable. There is no evidence, however, of positive selective attention effects on recognition accuracy with single-item displays. One failure to find such an effect was reported by Grindley and Townsend (1968). It is argued that in the study of Grindley and Townsend sub-optimal conditions were used and that a more elaborate replication of their study is in order. In the experiment reported here, an exposure duration resulting in 75% correct recognitions of target letters was determined per subject. This exposure time was used in the subsequent experimental sessions. In the experimental trials, single letters were presented on one out of five positions on an imaginary circle around a fixation point. The position of the impending target item was either cued or not cued by presenting either one or five dots at corresponding positions on the circumference of a similar, but somewhat larger, imaginary circle. The results showed a small, but highly significant, improvement in recognition accuracy when the position of the target letter was cued. It is concluded that cueing enhances recognition accuracy in single-item displays. Such an effect can only be shown if optimal experimental conditions are used.