Diana Moreno

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.

Effects of Trial-Specific Verbal Descriptions on Matching-to-Sample Performances of Children and Adults

Effects of verbal descriptions of stimulus relations on second-order identity matching were evaluated by arranging a sentence-completion requirement prior to matching a comparison to a sample stimulus. Sixteen college students (X=19 years) and 16 elementary school children (X=10 years) participated. Three experimental groups at each age were exposed to variants in the sentence completion format: descriptions of (1) matching contingencies, (2) relevant stimulus dimensions, or (3) choice performance. A control group had no exposure to sentences. Effects of verbal descriptions were evaluated on acquisition and transfer of matching. Across ages, experimental groups demonstrated higher accuracy during training and transfer tests. Between ages, adults matched more accurately than children; only control children never matched above chance. These findings are discussed in terms of the influence of verbal behavior on the acquisition and transfer of inductive repertoires in humans.