Richardson, J.V. & Baron, A.(2008).
Avoidance of timeout from response-independent food:
effects of delivery rate and quality.
Journal of the Experimental Analysis of Behavior, 89, 169-181.
In three experiments, a rat’s lever presses could postpone timeouts
from food pellets delivered on response-independent schedules. In Experiment 1,
the pellets were delivered at variable-time (VT) rates ranging from VT 0.5 to
VT 8 min. Experiment 2 replicated the VT 1 min and VT 8 min conditions of
Experiment 1 with new subjects. Finally, subjects in Experiment 3 could
postpone timeouts from delivery of pellets that differed in quality rather
than quantity (unsweetened versus sweetened pellets). In general, response
rates and success in avoiding increased as a function of the rate and
quality of the pellets. Also, performance efficiency increased as the
experiments progressedÑthat is, the avoidance response occurred later
and later in the response-timeout interval. The results support the
conclusion that timeout from reinforcement has functional properties
similar to those of more commonly studied aversive stimuli (e.g., shock).
Key words: free-operant avoidance, timeout from food, variable time schedules, food amount, food quality, avoidance efficiency, lever press, rats