Age-related preferences for paced and unpaced tasks in chained schedules of reinforcement

Younger and older men were studied on chained operant schedules. A response in the initial link produced a terminal link where a sequence of 10 key presses was reinforced with money. In different conditions, the time available for each key press was varied from .5 sec to an unlimited amount, and the speed with which the men produced the terminal links containing the paced and unpaced sequences was taken as an index of preference for the terminal link conditions. When the men had difficulty adjusting to pacing, initial link speed was directly related to reinforcement rate in the terminal link: the greater the reinforcement, the faster the speed. This effect was stronger among the older men, who had more difficulty adjusting to pacing. With continued exposure to pacing, however, men of both ages adjusted more readily and the speed-reinforcement relationship decreased. These results suggest that the role of monetary reinforcement in determining task preferences is moderated by other factors such as task difficulty.