Bouts of responding: the relation between bout rate and the rate of variable-interval reinforcement.
By nose poking a lighted key, rats obtained food pellets on either a variable-interval schedule of reinforcement or a schedule that required an average of four additional responses after the end of tile variable-interval component (a tandem variable-interval variable-ratio 4 schedule). With both schedule types, the mean variable interval was varied between blocks of sessions from 16 min to 0.25 min. Total rate of key poking increased similarly as a function of the reinforcer rate for the two schedule types, but response rate was higher with than without the four-response requirement. Analysis of log survivor plots of interresponse times showed that key poking occurred in bouts. The rate of initiating bouts increased as a function of reinforcer rate but was either unaffected or was decreased by adding the four-response requirement. Within-bout response rate was insensitive to reinforcer rate and only inconsistently affected by the four-response requirement. For both kinds of schedule, the ratio of bout time to between-bout pause time was approximately a power function of reinforcer rate, with exponents above and below 1.0.
Shull
Richard L
RL
Department of Psychology, Box 26170, The University of North Carolina-Greensboro, Greensboro, North Carolina 27402-6170, USA. rlshull@uncg.edu
Grimes
Julie A
JA
Bennett
J Adam
JA
D000818:Animals; D001522:Behavior, Animal; D005247:Feeding Behavior; D008297:Male; D011897:Random Allocation; D051381:Rats; D012054:Reinforcement, Psychology; D013997:Time Factors