Stimulus-response compatibility effects in a manual tracking task.

The purpose of this study was to determine whether there are stimulus-response (S-R) compatibility effects in a manual tracking task for male and female subjects of different ages. 20 healthy men and 20 healthy women in each of three different age groups (20 to 39, 40 to 59, and 60 to 79 years) participated (total N = 120). Subjects performed extension and flexion movements of the index finger metacarpophalangeal joint to track a computer-screen cursor along a target sine wave. The hand and forearm were positioned so that the finger movement was either vertical or horizontal, and the computer monitor was positioned so that the voluntary cursor movement was either vertical or horizontal. Each subject performed four different tracking tests corresponding to the four different ensembles of hand-forearm position and monitor position. There were significant differences in tracking performance between test ensembles in both women and men aged 60 to 79 years, and the compatible ensembles showed the superior performance. The results suggest that S-R compatibility effects exist in elderly women and elderly men performing a finger-movement tracking task, and these effects are consistent with impaired information processing in elderly persons. More research is needed on how S-R compatibility affects performance in persons with cerebral lesions.