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…

Four experiments were conducted to study the contents of human instrumental conditioning. Experiment 1 found positive transfer between a discriminative stimulus (S[superscript D] and an instrumental response (R) that shared the outcome (O) with the response that was originally trained with the S[superscript D], showing the formation of an…

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…

Early and intensive behavioral intervention (EIBI) is an approach to treating the behavioral deficits and excesses observed in children with autism spectrum disorders. The magnitude of improvement in the overall functioning of children receiving EIBI has stimulated additional research and widespread clinical dissemination through the publication…

The current study examined the impact of both the tendency to worry (trait worry) and the process of worry (state worry) on subsequent behavioral responding in a schedule discrimination learning task. High and low trait worriers were randomly assigned to a state worry or relaxation incubation condition and completed a test of executive functioning…

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…

Both animals and human toddlers can find an object in a rectangular enclosure after they have been disoriented. They use geometric cues (relative lengths of walls) to discriminate among different corners (e.g. long wall to the left, short to the right). It has been claimed that this ability is "modular", i.e. exclusively geometric. The present…

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…

Participants read lists of words and then made recognition judgments to pairs of words, each of which consisted of a prime word and a test word. At issue was the effect of a semantic relationship between the prime word and the test word on the recognition judgment to the test word. Under standard recognition conditions, semantic priming impeded…

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…

Monkeys trained in either one-trial recognition at 8- to 10-min delays or multi-trial discrimination habits with 24-h intertrial intervals received systemic cholinergic and dopaminergic antagonists, scopolamine and haloperidol, respectively, in separate sessions. Recognition memory was impaired markedly by scopolamine but not at all by…

Relational responding and peak shift were found to be related. In two experiments, pigeons were trained to make a successive discrimination by either the blackout method of errorless learning or training with extinction. In experiment 1, pigeons trained with extinction learned a circle-sized discrimination more quickly than pigeons trained with…