Effects of visual demonstration, verbal instructions, and prompted verbal descriptions on the performance of human subjects in conditional discriminations.

A study was conducted to confirm prior results concerning the role of prompted verbal descriptions of visually demonstrated stimulus relations in the acquisition and transfer of identity, difference, and similarity-matching relations (Ribes et al., 1988). Four groups of human adults were trained with these three matching relations under four different procedures: (1) visual demonstration without response requirement, (2) verbal instructions, (3) visual demonstration plus prompted verbal description, and (4) visual demonstration plus verbal instructions. These procedures were presented at the beginning of the training period before subjects could respond to the experimental task. Although most subjects in the four groups acquired the conditional discrimination under the three matching relations, only those in the two instruction-related groups showed some intramodal and extramodal transfer in tests with stimuli that had not been used in training. These results suggest the importance of measuring extra-situational and trans-situational generalization, and raise the need to distinguish between formal and functional verbal factors in the regulation of human behavior.