ANALYSIS OF A GUIDED‐RESPONSE PROCEDURE IN VISUAL DISCRIMINATIONS BY RATS

A guided‐response procedure was used to train a visual pattern discrimination by rats in a modified Sutherland box. The method consisted of guiding the animal to the correct choice by means of a retractable bridge that led to reinforcers, followed by gradually removing this prompt. This method was compared to a stimulus‐fading procedure, in which the initial differences betwen discriminative stimuli were gradually faded until they differed only with respect to the critical dimension for discrimination, and to a trial‐and‐error procedure. Both gradual procedures resulted in fewer errors compared to the trial‐and‐error procedure. The higher efficiency of the fading procedures was attributed to less aversiveness derived from performance with few errors and to the use of step‐by‐step requirements relative to the criterion performance.