The basis of behavioral momentum in the nonlinearity of strength

The persistence of operant responding in the context of distractors and opposing forces is of central importance to the success of behavioral interventions. It has been successfully analyzed with Behavioral Momentum Theory. Key data from the research inspired by that theory are reanalyzed in terms of more molecular behavioral mechanisms: the demotivational effects of disruptors, and their differential impacts on the target response and other responses that interact with them. Behavioral momentum is regrounded as a nonlinear effect of motivation and reinforcement rate on response probability and persistence. When response probabilities are high, more energy is required to further increase or to decrease them than when they are low. Classic Behavioral Momentum Theory effects are reproduced with this account. Finally, it is shown how the new account involving motivation and competition is closely related to the metaphor of force and action that is at the core of Behavioral Momentum Theory.     

The effect of physical fitness training on reaction time in youth with intellectual disabilities

The purpose of this study was to assess whether reaction time in persons with intellectual disabilities can be improved with an exercise program. 50 children and adolescents (M age = 14.7 yr., SD = 1.4, range = 11-18) with mild intellectual disability without Downs syndrome were randomly divided into control (20 boys, 5 girls) and experimental (19 boys, 6 girls) groups. The experimental group participated in a structured physical fitness program for 12 weeks. Reaction time was assessed at baseline and after 12 weeks. Significant improvements in reaction time were observed in the exercise group but not for the control group. Results indicated that reaction time can be improved with an exercise program in youth with intellectual disability.     

Differential reinforcement and stimulus control of not responding

Pigeons were trained to respond with equal variable-interval reinforcement in the presence of a white key and also a white key with a vertical line. They were then trained not to respond to the vertical line by extinguishing the response or by reinforcing its non-occurrence at various frequencies. During training, the rate of key-pecking in the presence of the white key, maintained by a constant variable-interval schedule of reinforcement, depended on the frequency of reinforcement in the presence of the line. When lines of different orientations were presented in a generalization test, birds trained with extinction responded more to other orientations than to the vertical line, whereas those trained with high frequencies of reinforcement for not responding tended to respond equally at all line orientations. Intermediate frequencies of reinforcement gave mixed results.     

Comparing positive and negative reinforcement: A fantasy experiment

We propose quantitative experimental approaches to the question of whether positive and negative reinforcement are functionally different, and discuss scientific and ethical concerns that would arise if these approaches were pursued.     

Stimuli, Reinforcers, and the Persistence of Behavior

This article reviews evidence from basic and translational research with pigeons and humans suggesting that the persistence of operant behavior depends on the contingency between stimuli and reinforcers, and considers some implications for clinical interventions.