An experimental analysis of task refusal: A comparison of negative reinforcement contingencies and transitions between academic tasks

The purpose of the study was to do an experimental analysis of academic task refusal for one girl with a developmental disability. Task refusal was analyzed in two experimental analyses. First, an analysis testing if the behavior was maintained by negative reinforcement, and the second, an analysis testing if the behavior was the result of transitioning between academic tasks differing in preference. Task refusal did not occur in the demand condition of the functional analysis, indicating that the behavior was not maintained by escape from demands. Conversely, task refusal occurred solely in the second experimental analysis when transitioning from a high-preferred to a low-preferred academic task. In this case, the context of terminating a preferred academic task and transitioning to a less preferred academic task was aversive but not the demand itself. In addition, when an embedded break condition was compared to a no break condition in a multielement design, task refusal was reduced to zero levels.     

Prediction and diagnosis: An experimental comparison

Diagnostic tasks differ from predictive tasks in two respects (1) the direction of the inference in diagnosis (from effect to cause) is inverse to that in prediction (from cause to effect), and (2) the event to be inferred is more distal in diagnostic tasks than in predictive tasks. These task features led to the hypothesis that a diagnostic task would be harder to learn than a predictive task. This hypothesis was tested in an experimental situation in which the causal mechanism was random sampling with replacement. Five groups of subjects with 10 subjects in each (two predictive and three diagnostic groups) were run in individual sessions with 100 trials of feedback training. The two predictive groups learned more rapidly and to a higher level compared to the diagnostic groups. Conclusion: the present data support the hypothesis that predictive tasks are easier to learn than comparable diagnostic tasks.     

An experimental analysis of negative reinforcement contingencies for adult-delivered reprimands

Seven adults participated in simulated teaching sessions with an experimenter who role played as a student with developmental disabilities. The experimenter engaged in problem behavior and either (a) terminated problem behavior contingent on participant reprimands (negative reinforcement) or (b) did not terminate problem behavior contingent on reprimands (extinction). Results suggested that reprimands were sensitive to negative reinforcement in the form of the immediate cessation of problem behavior. These preliminary findings support role play as a potentially viable laboratory model for analyzing behaviors of typical adults.     

On neurotransmitter mechanisms of reinforcement and internal inhibition

Experiments reported in this study have been performed in order to investigate cholinergic and GABA-ergic neurotransmitter systems and substance P in the realization of internal inhibition and pain reinforcement. This was accomplished during the elaboration of inhibitory and defensive conditioned reflexes to light flashes in alert, nonimmobilized rabbits. Present results together with a review of past research indicate that the cholinergic system is directly involved in transmitting the effects of pain reinforcement to neocortical neurons. Substance P, a neuropeptide, reduces the background activity of neocortical and hippocampol neurons and the response of cortical neurons to pain and positive conditioned stimuli. The cholinergic system and substance P exert a modulating effect on the elaboration of internal inhibition. Phenybut, a GABA derivative capable of penetrating the blood-brain barrier, enhances inhibitory hyperpolarization in the cerebral cortex and improves discrimination between the inhibitory and reinforcing light flashes. It appears, therefore, that the GABA-ergic system plays a leading part in the elaboration of internal inhibition. Neuronal activity and slow potential changes in response to positive conditioned and pain stimuli occur in the same direction after administering the preparations, and the dynamics of these changes is different from that in responses to inhibitory stimuli. It may be supposed on these grounds that the neurotransmitter and neuromodulator systems studied possess a considerable degree of plasticity.