The conditions under which stimulus over-selectivity occurred were studied using a matching-to-sample procedure with non-autistic adults. A matching-to-sample discrimination learning task with a number of sample-comparison retention intervals was used. The results demonstrated that an increase in retention interval increased the degree of stimulus…

Thirty-six healthy participants received a discrimination learning task requiring the identification of a relevant stimulus dimension. After successful learning, the relevant dimension was shifted unannounced. All exemplars of the two dimensions presented after the shift were novel, implying a "total change" design. In three experimental…

Nonhuman animals, like humans, appear sensitive to the structure of the elements of sequences, perhaps even when the structure relates nonadjacent elements. In the present study, we examined the contribution of chunking, rule learning, and item memory when rats learned serial patterns composed of two interleaved subpatterns. In one group, the…

In this article, I discuss the concepts of "private stimuli," "covert responses," and "private events," emphasizing three aspects: the conditions under which private stimuli may acquire discriminative functions to verbal responses, the conditions of unobservability of covert responses, and the complexity of events or phenomena described as…

We explored the circumstances in which rats engage either declarative memory (and the hippocampus) or habit memory (and the dorsal striatum). Rats with damage to the hippocampus or dorsal striatum were given three different two-choice discrimination tasks (odor, object, and pattern). These tasks differed in the number of trials required for…

Behavioral, neuropsychological, and brain imaging research points to a dedicated system for processing number that is shared across development and across species. This foundational Approximate Number System (ANS) operates over multiple modalities, forming representations of the number of objects, sounds, or events in a scene. This system is…

Following training on an easy size discrimination, pigeons were matched on the basis of stimulus control by the positive stimulus following generalization tests. Three subjects were immediately retrained on a more difficult discrimination along the same dimension, while the remaining three subjects were retrained after a six-month delay. The…

To determine why the familiarization-novelty paradigm tends to underestimate the ability of infants under 4 months of age to detect unidimensional differences between stimuli, groups of 14- and 20-week-olds were given unidimensional discrimination problems of varying difficulty under conditions of brief and prolonged familiarization. (Author/JMB)

Forty-eight four-month-old infants were tested in a habituation-dishabituation discrimination paradigm using vertically symmetrical, horizontally symmetrical, and asymetrical forms. Results suggest that babies respond to "goodness of organization" rather than to details unique to particular symmetrical patterns. (Author/RH)

Discrete-trial teaching is an instructional method commonly used to teach social and academic skills to children with an autism spectrum disorder. The purpose of the current study was to evaluate the indirect effects of discrete-trial teaching on 3 students' stereotypy. Instructions, feedback, modeling, and rehearsal were used to improve 3…

Examines the ability of preschool children to discriminate perceptually among novel forms frequently employed in referential communication tasks. (JMB)