title: Effect of task demand and stimulus relevance on preattentive processing.
abstract: Evidence of cognitively controlled processes influencing preattentive processes is provided. In the first experiment, preattentive processing associated with a discrimination task was compared with that associated with a reaction task. An increase in processing time due to preattentive processes was only found for the discrimination task. In the second experiment, the effects of different amounts of stimulus relevance on preattentive processing were investigated. Stimulus relevance was varied by changing the spatial and temporal distance in cognitively controlled processing. The relevance of the stimulus was proportional to the amount of preattentive processing. It was concluded that the influence of cognitively controlled processing on preattentive processing is moderated by task demand and stimulus relevance. These results are based on observations concerning processing time.
mesh_terms: D000328:Adult; D001288:Attention; D004193:Discrimination Learning; D005260:Female; D006801:Humans; D008297:Male; D010364:Pattern Recognition, Visual; D011930:Reaction Time