The Role of Intertarget Distance in Visual Search for Multiple Targets

Subsequent search misses (SSM) refer to the decrease in accuracy in detecting a second target after the first target has been found in visual search task. The experiment investigated the role of intertarget distance in a dual-target visual search. The subject’s task was to find a target or targets (T letters) among distracters (L letters). In each trial there was either one high-salient target, one low-salient target, two targets (one high-salient and one low-salient) or no targets. In the dual-target condition, the targets were presented at various distances. Accuracy and reaction time for dual-target conditions and for one low-salient target condition were compared. The results revealed the role of intertarget distance in SSM. The SSM errors were observed only at particular intertarget distances. The results of the present study are discussed in relation to attentional blink studies and experiments on the dead zone of attention