title: Dissociation of instrumental and Pavlovian contingencies in a discriminated instrumental procedure.
abstract: Four pigeons were exposed to an experimental procedure in which the presentation of a stimulus at one intelligence panel in a longbox signaled the opportunity to obtain response-dependent food contingent upon withdrawal from the stimulus to the other end of the box. Four other pigeons in addition received unsignaled, response-independent food during the intertrial interval. Both groups of subjects learned to withdraw from the stimulus during stimulus presentations, but the subjects who received response-independent food during the intertrial interval learned to do so faster than the subjects in the other group. Subjects who received response-independent food in the absence of the stimulus hardly ever contacted the stimulus upon its presentation, whereas subjects in the other group (food only presented upon withdrawal from the stimulus) contacted the stimulus frequently. Withdrawal behavior from the stimulus decreased when it was no longer reinforced, while random presentations of the stimulus and response-independent food eliminated stimulus contact behavior.
authors.affiliation: Netherlands Institute for Brain Research, Amsterdam, The Netherlands.
authors.forename: A
authors.initials: A
authors.lastname: Van Hest
authors.affiliation: Tilburg University, Tilburg, The Netherlands.
authors.forename: F
authors.initials: F
authors.lastname: Van Der Schoot
authors.affiliation: Tilburg University, Tilburg, The Netherlands.
authors.forename: P
authors.initials: P
authors.lastname: Kop
authors.affiliation: Netherlands Institute for Brain Research, Amsterdam, The Netherlands.
authors.forename: F
authors.initials: F
authors.lastname: Van Haaren