Cognitive spatial-motor processes. 6. Visuomotor memory scanning.

Fourteen human subjects performed in a modified Sternberg memory-scanning task. First, they made a series of 2-6 movements in different directions from a central point towards peripheral lights on a planar working surface ("list trials"). Then, after a warning signal, one of the previous list stimuli, except the last, was presented again ("test trial"). Subjects were instructed to move in the direction of the stimulus which was presented next in sequence in the list. The mean reaction time (RT) in the test trials increased as a linear function of the number of movements, S, in the list: Mean RT (ms) = 105 + 205.8S (2 less than or equal to S less than or equal to 6). This finding suggests that the task involves memory scanning of visuomotor list items.