Effects of target luminance and cue validity on the latency of visual detection

The results reveal that when target Luminance is varied randomly within trial blocks, the cue-validity effect grows with declining target luminance.

Abstract

Hughes (1984) has reported that the magnitude of the cue-validity effect in luminance detection is unaffected by target luminance. In three experiments, we explored the possible basis of this counterintuitive finding. The experiments focused on the design of the Hughes study, in which target luminance was treated as a between-blocks variable. Our results reveal that when target luminance is varied randomly within trial blocks, the cue-validity effect grows with declining target luminance. The difference between our findings and those of Hughes is interpreted in terms of cue-utilization strategies, which may adapt to target luminance when luminance remains invariant within trial blocks. Several alternative conceptions of the nature and locus of the cuevalidity effect in luminance detection are considered in light of these results.