Semester

Fall

Date of Graduation

2000

Document Type

Thesis

Degree Type

MA

College

Eberly College of Arts and Sciences

Department

Psychology

Committee Chair

Michael Perone.

Committee Co-Chair

Kennon A. Lattal

Committee Member

Stanley H. Cohen

Abstract

Session-reduction procedures have been employed to assess molar control of avoidance responding. By conceptualizing session reduction as a delayed timeout from avoidance, the present study investigated the limits of molar control while minimizing several methodological limitations inherent in such procedures. Six times during each session, a two-link chain schedule was superimposed on a baseline schedule of variable-cycle shock avoidance. Completion of the initial link (fixed-ratio 10 schedule) produced a timeout following a signaled delay during which the avoidance schedule remained operative. For most rats, the delay was manipulated across conditions from 0 s to 60 s. Control by the delayed timeout was indicated by elevated initial-link responding relative to baseline avoidance responding. Reliable initial-link elevations were obtained only when the timeout was presented immediately upon the completion of the initial link. These findings cast doubt on previous interpretations of session-reduction as molar reinforcement, and underscore the importance of response-reinforcer contiguity.

Share

COinS