In both discrimination learning and partial reinforcement, transitions may occur from nonrewarded to rewarded trials (NR transition). In discrimination learning, NR transitions may occur in two different stimulus alternatives (NR different transitions). In partial reward, NR transitions may occur in a single stimulus alternative (NR same…

The Rescorla-Wagner model is one of the cornerstones of learning theory. However, many students in undergraduate courses find the model's concepts difficult to grasp, and the model is often the students' first exposure to computational models in psychology. This article describes an interactive simulation based on an Excel(r) spreadsheet program…

Pigeons pecked left versus right keys contingent upon the color presented at 1 of those locations. Spatial-response latencies were shorter when the color appeared at the same location as the required response than at the opposite location. This Simon effect occurred when the stimulus on the alternative key was constant, varied from trial to trial,…

Three experiments compared the learning of lower-dimensional family resemblance categories (4 dimensions) with the learning of higher-dimensional ones (8 dimensions). Category-learning models incorporating error-driven learning, hypothesis testing, or limited capacity attention predict that additional dimensions should either increase learning…

Drash and Tudor describe six sets of reinforcement contingencies which may be present in the environments of some children eventually diagnosed with autism and suggest that these contingencies account for the etiology of "autistic" behaviors. Nevertheless, merely observing such contingencies in the environments of these children is insufficient to…

Cholinergic systems are critical to the neural mechanisms mediating learning. Reduced nicotinic cholinergic receptor (nAChR) binding is a hallmark of normal aging. These reductions are markedly more severe in some dementias, such as Alzheimer's disease. Pharmacological central nervous system therapies are a means to ameliorate the cognitive…

There is a close correlation between long-term potentiation (LTP) in the synapses of lateral amygdala (LA) and fear conditioning in animals. We predict that reversal of LTP (depotentiation) in this area of the brain may ameliorate conditioned fear. Activation of group II metabotropic glutamate receptors (mGluR II) with DCG-IV induces…

This article reviews evidence and theories concerning the nature of stimulus representations in Pavlovian conditioning. It focuses on the elemental approach developed in stimulus sampling theory (R. C. Atkinson & W. K. Estes, 1963; R. R. Bush & F. Mosteller, 1951b) and extended by I. P. L. McLaren and N. J. Mackintosh (2000, 2002) and contrasts…

The ability of a reinforcer to maintain behavior decreases as a hyperbolic function of its delay. This discounted value can help explain impulsivity defined as the choice of an immediate, small reinforcer over a delayed, large reinforcer. Human operant studies using consumable reinforcers such as videos have found impulsivity with delays under 1…

To examine the effects on concurrent performance of independent manipulations of response-unit duration and number, 6 hens were exposed to concurrent second- order schedules of reinforcement. Each first-order operant unit required completion of a fixed-ratio schedule within the time specified by a fixed- interval schedule, with one further…

Contingencies of reinforcement specify how reinforcers are earned and how they are obtained. Ratio contingencies specify the number of responses that earn a reinforcer, and the response satisfying the ratio requirement obtains the earned reinforcer. Simple interval schedules specify that a certain time earns a reinforcer, which is obtained by the…

Arbitrarily applicable derived relational responding has been argued by relational frame theorists to be a form of operant behavior. The present study examined this idea with 4 female participants, ages 4 to 5 years old, who could not perform a series of problem-solving tasks involving arbitrary more than and less than relations. In a combined…

Pigeons were trained in three experiments with a two-key, concurrent-chains choice procedure. The initial links were equal variable-interval schedules, and the terminal links were random-time schedules with equal average interreinforcement intervals. Across the three experiments, the pigeons either stayed in a terminal link until a reinforcer was…

This document contains supplemental materials for special needs high school students intended to facilitate their mainstreaming in regular air conditioning and refrigeration courses. Teacher's materials precede the materials for students and include general notes for the instructor, additional suggestions, two references, a questionnaire on the…

THE STUDY INVESTIGATED SOME OF THE RELATIONSHIPS BETWEEN A CHILD'S VERBAL BEHAVIOR AND ENVIRONMENTAL EVENTS NECESSARY IN ACQUIRING LANGUAGE. TWO TRAINABLE RETARDATES (FROM A GROUP OF SIX, AGED 3-6 TO 5) WITH A FUNCTIONAL VOCABULARY OF NO MORE THAN TWO OR THREE WORDS WERE SEEN INDIVIDUALLY IN 20- TO 30-MINUTE SESSIONS TWICE A WEEK DURING A 4-MONTH…