Attentional control via parallel target-templates in dual-target search.
Simultaneous search for two targets has been shown to be slower and less accurate than independent searches for the same two targets. Recent research suggests this 'dual-target cost' may be attributable to a limit in the number of target-templates than can guide search at any one time. The current study investigated this possibility by comparing behavioural responses during single- and dual-target searches for targets defined by their orientation. The results revealed an increase in reaction times for dual- compared to single-target searches that was largely independent of the number of items in the display. Response accuracy also decreased on dual- compared to single-target searches: dual-target accuracy was higher than predicted by a model restricting search guidance to a single target-template and lower than predicted by a model simulating two independent single-target searches. These results are consistent with a parallel model of dual-target search in which attentional control is exerted by more than one target-template at a time. The requirement to maintain two target-templates simultaneously, however, appears to impose a reduction in the specificity of the memory representation that guides search for each target.
School of Psychology, College of Biological and Medical Science, University of Leicester, Leicester, United Kingdom.
Doug J K
DJ
Barrett
Medical Research Council Institute of Hearing Research, Nottingham, United Kingdom.
Oliver
O
Zobay
D000328:Adult; D001288:Attention / Q000502:physiology*; D006801:Humans; D008954:Models, Biological; D011930:Reaction Time / Q000502:physiology; D012044:Regression Analysis; D012815:Signal Processing, Computer-Assisted; D013647:Task Performance and Analysis; D055815:Young Adult