The systematic anticipation and preservation errors produced by pigeons around the
reversal point in midsession reversal (MSR) learning experiments suggest that an internal …

Inspired by Spence's seminal work on transposition, we propose a synthetic approach to
understanding the temporal control of operant behavior. The approach takes as primitives …

The midsession reversal paradigm confronts an animal with a two-choice discrimination task
where the reward contingencies are reversed at the midpoint of the session. Species react to …

Discrimination reversal learning has been used as a measure of species flexibility in dealing
with changes in reinforcement contingency. In the simultaneous-discrimination, midsession …

What are the mechanisms by which behavior is organized sequentially over time? The
recently developed mid-session reversal (MSR) task offers new insights into this …

Pigeons (Columba livia) produce many anticipatory and perseverative errors on
discrimination tasks with a reversal of reward contingencies partway through the session …

When animals make decisions that are suboptimal, it helps us to identify the processes that
have evolved to produce this behavior. In an earlier article, I discussed three examples of …

The midsession reversal task involves a simultaneous discrimination between stimuli S1
and S2. Choice of S1 but not S2 is reinforced during the first 40 trials, and choice of S2 but …

In a 2-stimulus visual discrimination choice task with a reversal in reward contingencies
midway through each session, pigeons produce a surprising number of both anticipatory …

Behavior may come under the control of time or number when such cues predict food
availability, but time tends to exert stronger control than does number. We asked how the …