Effects of stimulus-response variables on the choice reaction time of mildly retarded adults.

Nonretarded and mildly retarded adults were compared in two experiments on an 8-choice reaction time (RT) task. Stimulus lights were either distant or close. Both groups responded more slowly when stimuli were distant, this effect being more marked for retarded subjects. Patterns of latencies suggested that, compared with nonretarded subjects, retarded subjects inspected information input for longer periods of time and made more inspections before responding. Faster RTs to stimuli nearest the ends and midline of the display and to stimulus repetitions indicated that retarded subjects were more reliant upon more discriminable cues in the stimulus display.