Temporal search as a function of the variability of interfood intervals.
We attempted to determine whether timing theories developed primarily to explain performance in fixed-interval reinforcement schedules are also applicable to variable intervals. Groups of rats were trained in lever boxes on peak procedures with a 30-, 45-, or 60-s interval, or a 30- to 60-s uniform distribution (Experiment 1); a 60-s fixed and 1- to 121-s uniform distribution between and within animals (Experiment 2); and a procedure in which the interval between food and next available food gradually changed from a fixed 60 s to a uniform distribution between 0 and 120 s (Experiment 3). In uniform interval schedules rats made lever responses at particular times since food, as measured by the distribution of food-food intervals, the distribution of postreinforcement pauses, and the mean response rate as a function of time since food. Qualitative features of this performance are described by a multiple-oscillator connectionist theory of timing.
Department of Psychology, Brown University, Providence, Rhode Island 02912, USA. russell_church@brown.edu
R M
RM
Church
D M
DM
Lacourse
J D
JD
Crystal
D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D005247:Feeding Behavior / Q000502:physiology*; D008297:Male; D051381:Rats; D012055:Reinforcement Schedule; D013997:Time Factors