CHOICE: SOME QUANTITATIVE RELATIONS

Abstract

Six pigeons responded in 56 conditions on a concurrent-chains procedure. Conditions included equal initial links and unequal terminal links, unequal initial links and equal terminal links and both unequal initial and terminal links. Although the delay-reduction hypothesis accounted for choice when the initial links were equal (mean deviation of 0.04), it did not fit the data when the initial links were unequal (mean deviation of 0.18). A modification of the delay-reduction hypothesis, replacing the rates of reinforcement with the square roots of these rates, fit the data better, than either the unmodified delay-reduction equation or Killeen''s (1982) model. The modified delay-reduction equation was also consistent with data from prior studies using concurrent chains. The absolute rates of responding in each terminal link were well described by the same hyperbola (Herrnstein, 1970) that describes response rates on simple interval schedules.