Shull, R. L., Gaynor, S. T., & Grimes, J. A. (2002).
Response rate viewed as engagement bouts: Resistance to extinction.
Journal of the Experimental Analysis of Behavior,
77, 211-231.
Rats obtained food pellets by nose poking a lighted key, the
illumination of which alternated every 50 s during a session
between blinking and steady, signaling either a relatively rich
(60 per hour) or relatively lean (15 per hour) rate of
reinforcement. During one training condition, all the reinforcers
in the presence of the rich-reinforcement signal were response
dependent (i.e., a variable-interval schedule); during another
condition only 25% were response dependent (i.e., a variable-time
schedule operated concurrently with a variable-interval
schedule). An extinction session followed each training block.
For both kinds of training schedule, and consistent with prior
results, response rate was more resistant to extinction in the
presence of the rich-reinforcement signal than in the presence of
the lean-reinforcement signal. Analysis of interresponse-time
distributions from baseline showed that differential resistance
to extinction was not related to baseline differences in the rate
of initiating response bouts or in the length of bouts. Also,
bout-initiation rate (like response rate) was most resistant to
extinction in the presence of the rich-reinforcement signal.
These results support the proposal of behavioral momentum theory
(e.g., Nevin & Grace, 2000) that resistance to extinction in
the presence of a discriminative stimulus is determined more by
the stimulus–reinforcer (Pavlovian) than by the
stimulus–response–reinforcer (operant) contingency.
Key words: resistance to change, behavioral momentum, extinction,
bouts, visits, key poke, rats