The purpose of the two experiments was to assess the effects of two levels of stimulus redundancy and three levels of irrelevant visual stimulation on performance in a successive discrimination task and a reproduction task. The results indicate that increases in redundancy facilitated performance in the reproduction task but had no appreciable…

Five preschool children at risk for mental retardation were taught to choose an odd stimulus which varied in one important dimension (e.g., form, color, or size) from other stimuli in a set. Oddity responding was shown to transfer across stimulus types, and learning was maintained for a minimum of six weeks. (Author/JW)

Because disabled learners may profit from procedures using gradual stimulus change, this study utilized a microcomputer to investigate the effectiveness of stimulus equalization, an error reduction procedure involving an abrupt but temporary reduction of dimensional complexity. The procedure was found to be generally effective and implications for…

A stimulus equivalence procedure for the acquisition of English and Spanish words was evaluated with two adolescents having head injuries. Following training on one task, subjects attained and maintained high scores on all matching-to-sample tasks. Results suggest the procedure is effective for teaching foreign language skills to head-injured…

Two studies compared performance on conditional and trial-unique delayed identity matching-to-sample procedures with five subjects having moderate to severe mental retardation and four subjects with mild mental retardation. Across the studies, six of nine subjects showed lower delayed-matching accuracy when fewer rather than more stimuli were…

Processing of a probe stimulus can be affected either positively or negatively by presenting a related stimulus immediately before it. According to structural accounts, such effects occur because processing of the prime activates or inhibits the mental representation of the probe before it is presented. In contrast, transfer-appropriate processing…

Paper is based on a dissertation submitted to Brown University in partial fulfillment of the requirements for the Ph.D. degree in Psychology, June, 1966.

Results of numerous human imaging studies and nonhuman neurophysiological studies on "reward" highlight a role for frontal, striatal, and thalamic regions in operant learning. By integrating operant and functional neuroimaging methodologies, the present investigation examined brain activation to two types of discriminative stimuli correlated with…

The neural mechanisms of fear suppression most commonly are studied through the use of extinction, a behavioral procedure in which a feared stimulus (i.e., one previously paired with shock) is nonreinforced repeatedly, leading to a reduction or elimination of the fear response. Although extinction is perhaps the most convenient index of fear…

A model of conditional discrimination performance (Davison & Nevin, 1999) is combined with the notion that unmeasured attending to the sample and comparison stimuli, in the steady state and during disruption, depends on reinforcement in the same way as predicted for overt free-operant responding by behavioral momentum theory (Nevin & Grace, 2000).…

Two time-delay conditions for teaching complex visual discriminations to 14 normal preschoolers, 12 with mild mental retardation, and 11 with moderate mental retardation were compared. Results indicated that for all populations and stimuli, time delay of multiple dynamic distinctive-feature prompts produced learning, while time delay of the single…

Sixteen individuals (ages 7-18) with moderate or severe mental retardation were taught to identify 2 comparative discriminations by a static or dynamic presentation procedure. No differences in percentage of unprompted correct responses were found between the two procedures in training, generalization, or maintenance. (Author/JDD)

Recognition scores of 12 moderately and mildly retarded children (mean ages 13 and 14 years) for positive and negative discriminative stimuli were tested after a single trial through a discrimination problem list. (Author/CL)

Examines the influences of behaviorist psychology on performance and instruction technologies. The basic assumptions of behaviorism are outlined, reinforcing contingencies are reviewed, conditioning is described, and such specific topics as stimulus control, behavior chaining, and successive approximation are discussed. (Author/JL)

Five experiments examined the relations between timing and attention using a choice time production task in which the latency of a spatial choice response is matched to a target interval (3 or 5 s). Experiments 1 and 2 indicated that spatial stimulus-response incompatibility increased nonscalar timing variability without affecting timing accuracy…