Attentional mechanisms in simple visual detection: a speed-accuracy trade-off analysis.
Recent spatial cuing studies have shown that detection sensitivity can be increased by the allocation of attention. This increase has been attributed to one of two mechanisms: signal enhancement or uncertainty reduction. Signal enhancement is an increase in the signal-to-noise ratio at the cued location; uncertainty reduction is a reduction in the uncertainty associated with the location of the target. In displays with low uncertainty, cuing effects are typically found only if targets are backwardly masked. This phenomenon is known as the mask-dependent cuing effect. This effect was investigated in four experiments using the response signal paradigm, which controlled for speed-accuracy tradeoffs. For unmasked targets, cues failed to improve detection accuracy when uncertainty was absent (Experiment 1), but large cuing effects were obtained when uncertainty was present (Experiment 2). For masked targets, stronger cuing effects were obtained with a backward pattern mask (Experiment 3) than with a simultaneous noise mask (Experiment 4). We conclude that the cuing effects in simple detection with well-localized targets are due to a dynamic signal enhancement mechanism.
Liu
Charles C
CC
University of Melbourne, Melbourne, Australia. charles.liu@muarc.monash.edu.au
Wolfgang
Bradley J
BJ
Smith
Philip L
PL
D000328:Adult; D000465:Algorithms; D001288:Attention; D003463:Cues; D005364:Field Dependence-Independence; D006801:Humans; D008960:Models, Psychological; D010470:Perceptual Masking; D011336:Probability; D011930:Reaction Time; D012016:Reference Values; D017603:Signal Detection, Psychological; D013028:Space Perception; D013997:Time Factors; D035501:Uncertainty; D014796:Visual Perception