Does Target Object Processing Affect Reaction Times in Simple Detection Spatial Cueing Tasks?

The current study tested the effect of varying target type and target set size during simple detection versions of Posner's exogenous spatial cueing task. The four target conditions consisted of a single letter, a single number, one of four possible letters, or one of four possible numbers. Responses were faster for numbers than for letters, but only when the cue-target lag was short, the target set included more than one potential number, and the cue and target appeared in different locations. These findings suggest that even during detection tasks, responses are influenced by the object features of the target. Methodological implications for spatial cueing studies and other types of visual perception research were discussed.