Lattal, K. A., & Williams, A. M. (1997).
Body weight and response acquisition with delayed reinforcement.
Journal of the Experimental Analysis of Behavior,
67, 131-143.
The relation between body weight and responding established with
unsignaled delayed reinforcement was investigated. In three
experiments, naive rats were deprived to either 70%, 80%, or 90%
of ad libitum weight and were then exposed to tandem
variable-interval 15-s
differential-reinforcement-of-other-behavior 30-s schedules. The
tandem schedule defined a resetting unsignaled
delay-of-reinforcement procedure. In the first experiment, speed
of magazine training, acquisition of lever pressing, and final
rate of lever pressing were related to body weight. In the next
experiment, lever pressing was established and maintained in rats
that were magazine trained at 70% of ad libitum weight but that
were then exposed to the delay procedure at 90% of ad libitum
weight. Responding did not change consistently either across or
within subjects in subsequent conditions in which body weight was
manipulated. In the final experiment, lever pressing was
established and maintained with delayed reinforcement in the
absence of magazine training for each of 2 rats at 70% and for 1
of 2 rats at 90% of ad libitum weight. The results further
illuminate the conditions under which responding can be
established in the absence of training and when such responses
are reinforced only following an unsignaled delay period.
Key words: acquisition, reinforcement delay, body weight, tandem
VI DRO schedule, lever press, rats