We tested whether teaching control by single stimulus samples in conditional discriminations would result in common control of two-stimuli compound samples, and vice versa. In Experiment 1, 5 participants were first taught four single-sample conditional discriminations. The first conditional discrimination was as follows: given sample stimulus P1,…

A linked perceptual class consists of two distinct perceptual classes, A' and B', the members of which have become related to each other. For example, a linked perceptual class might be composed of many pictures of a woman (one perceptual class) and the sounds of that woman's voice (the other perceptual class). In this case, any sound of the…

Individuals with anxiety disorders often do not respond to safety signals and hence continue to be afraid and anxious. Consequently, it is important to develop paradigms in animals that can directly study brain systems involved in learning about, and responding to, safety signals. We previously developed a discrimination procedure in rats of the…

A robust finding in humans and animals is that intermixed exposure to 2 similar stimuli (AX/BX) results in better discriminability of those stimuli on test than does exposure to 2 equally similar stimuli in 2 separate blocks (CX_DX)--the intermixed-blocked effect. This intermixed-blocked effect may be an example of the superiority of spaced over…

These 6 experiments explored the ability of moving random dot patterns to attract attention, as measured by a simple probe-detection task. Each trial began with random motion (i.e., dots linearly moved in random directions). After 1 s motion in 1 hemifield became gradually coherent (i.e., all dots moved up-, down-, left-, or rightwards, or either…

Learning styles in capuchin monkeys were assessed with a computerized reversal-learning task called the mediational paradigm. First, monkeys were trained to respond with 90% accuracy on a two-choice discrimination (A+B-). Then the authors examined differences in performance on three different types of reversal trials (A-B+, A-C+, B+C-), each of…

Autistic and typical children mastered a simultaneous discrimination task with three sets of all-tactile compound stimuli. During training, responding to one stimulus (S+) resulted in rewards whereas responding to the alternative (S-) was extinguished. Test 1 was conducted with recombinations of S+ and S- elements. In Test 2, the test stimulus to…

Stereotypic behavior exhibited by a third grade boy with autism was maintained by automatic reinforcement and occurrences of stereotypy were brought under stimulus control. The intervention consisted of pairing a green discriminative stimulus card (SD) with free access to stereotypy and a red card (SD absent) with vocal redirection and blocking…

In many discrimination-learning tests, spatial separation between stimuli and response loci disrupts performance in rhesus macaques. However, monkeys are unaffected by such stimulus-response spatial discontiguity when responses occur through joystick-based computerized movement of a cursor. To examine this discrepancy, five monkeys were tested on…

Eighteen undergraduates participated in studies designed to examine the factors that produce transfer of contextual functions to novel stimuli in second-order conditional discriminations. In Study 1, participants selected comparison B1 given sample A1 and comparison B2 given sample A2 in a matching-to-sample procedure. Contextual stimuli X1 or X2…

The differential outcomes effect is a phenomenon where use of a choice-unique outcome for each type of correct choice in a conditional discrimination task increases rate of learning and overall accuracy, as compared to the traditional use of a single, common outcome for all types of correct choices. This phenomenon was successfully demonstrated…

In Experiment 1, rats were trained on a discrimination in which one occasion setter, A, signaled that one cue (conditioned stimulus, CS), x, would be followed by one outcome, p (unconditioned stimulus, US), and a second CS, y, by a different outcome, q (x [right arrow] p and y [right arrow] q); a second occasion setter, B signalled the reverse…

Two groups of rats were trained in a symbolic delayed matching-to-sample task with a 0-s delay to discriminate sample stimuli that consisted of sequences of tone bursts. For one group, sequences varied in number with total sequence duration controlled. For the other group, total sequence duration, sum of the tone durations, and sum of the gap…

The single-stimulus (SS) preference assessment procedure has been described as more appropriate than the paired stimulus (PS) procedure for "lower functioning" individuals, but this guideline's vagueness limits its usefulness. We administered the SS and PS preference assessment procedures with food items to seven individuals with severe…

The steps involved in teaching multiple discrimination to disabled students are listed for ecological, performance, functional, and stimulus analyses. Additional considerations, including stimulus modification and design of the instructional sequence (successive or cumulative approaches), are reviewed. (CL)