The context in which reward-paired cues are encountered can resolve ambiguity and set the occasion for appropriate reward-seeking. The psychological processes by which contexts regulate reward-seeking remain unclear as contexts are diffuse and difficult to isolate from other stimuli. To overcome this, we modeled a context as a phasic and discrete…

Feeding in "Aplysia" provides an amenable model system for analyzing the neuronal substrates of motivated behavior and its adaptability by associative reward learning and neuromodulation. Among such learning processes, appetitive operant conditioning that leads to a compulsive-like expression of feeding actions is known to be associated…

Recent studies have demonstrated that the expectation of reward delivery has an inverse relationship with operant behavioral variation (e.g., Stahlman, Roberts, & Blaisdell, 2010). Research thus far has largely focused on one aspect of reinforcement--the likelihood of food delivery. In two experiments with pigeons, we examined the effect of two…

While knowing what to expect is important, it is equally important to know when to expect it and to respond accordingly. This is apparent even in simple Pavlovian training situations in which animals learn to respond more strongly closer to reward delivery. Here we report that the nucleus accumbens core, an area well-positioned to represent…

A theory devised initially on the basis of instrumental reward schedule data, such as the PREE, was extended to deal with various Pavlovian findings. These Pavlovian findings include blocking, unblocking, relative validity, positive and negative patterning, renewal, reinstatement, reacquisition, and inhibition. In addition, the sequential model…

Humans discount larger delayed rewards less steeply than smaller rewards, whereas no such magnitude effect has been observed in rats (and pigeons). It remains possible that rats' discounting is sensitive to differences in the quality of the delayed reinforcer even though it is not sensitive to amount. To evaluate this possibility, Experiment 1…

The results of a group of studies, the objective of which was to clarify the conditions that account for the effectiveness of verbal approbation, are reported. Among the most significant findings were: (1) that the reinforcement properties of verbal approval are susceptible to distortion, misinterpretation or enhancement and must be applied in a…

Research supported in whole by Public Health Service Grant HD-00908 from the National Institute of Child Health and Human Development.

A primary purpose of the token system is to expand the operant model in order to provide a broader reinforcement base. The ten procedural considerations necessary for implementing a token system are presented. Beyond this, fundamental knowledge of operant principles remains essential in order to apply the token system correctly. (Author/KJ)

This paper examines the acquisition of superstitious behavior in young children. Six preschool children were exposed to a 15 minute fixed-time inter-reinforcement interval (FT-15") schedule while another six preschoolers were exposed to a 30 minute fixed-time inter-reinforcement interval (FT-30") schedule. In a free-operant laboratory…

Examines three troublesome questions concerning the effects of behavior modification: (1) what other conditionings may occur besides the simple one desired, (2) what type of personality modification is taking place along with behavior modification, and (3) what type of society will result when it consists of individuals trained in this manner?…

This research was supported by Research Grant No. 30-200-50, Indiana University Foundation, Indiana University.

Eight- and 9-year-olds (N=56) were studied to determine the degree to which counterconditioning could alter the positive or negative value acquired by a neutral stimulus in a conditioning situation. Dependent measures used to assess the effects of conditioning were found to have no independent effect on subsequent evaluations of the once-neutral…