Appel, J. B. (1963).
Aversive aspects of a schedule of positive reinforcement.
Journal of the Experimental Analysis of Behavior,
6, 423-428.
Six male White Carneaux pigeons were trained to peck at one of
two keys to obtain food on several fixed-ratio schedules of
reinforcement. Concurrently the first response on a second key
could, I--change the conditions of visual stimulation and remove
the food reinforcement contingency, II--change the conditions of
stimulation and have no effect upon the reinforcement
contingency, or III--do nothing. The second response on the
stimulus change key always restored baseline conditions. When
second-key responses produced a stimulus change, the number of
such responses was a function of the ratio value on the first
key. Typically second-key responses occurred before the start of
fixed-ratio runs. The duration of stimulus change periods was an
exponential function of the number of responses required for
reinforcement when the possibility for reinforcement was not
disturbed by periods of stimulus change (Condition II).