Do rats learn conditional independence?

If acquired associations are to accurately represent real relevance relations, there is motivation for the hypothesis that learning will, in some circumstances, be more appropriately modelled, not as direct dependence, but as conditional independence. In a serial compound conditioning experiment, two groups of rats were presented with a conditioned stimulus (CS1) that imperfectly (50%) predicted food, and was itself imperfectly predicted by a CS2. Groups differed in the proportion of CS2 presentations that were ultimately followed by food (25% versus 75%). Thus, the information presented regarding the relevance of CS2 to food was ambiguous between direct dependence and conditional independence (given CS1). If rats learnt that food was conditionally independent of CS2, given CS1, subjects of both groups should thereafter respond similarly to CS2 alone. Contrary to the conditionality hypothesis, subjects attended to the direct food predictability of CS2, suggesting that rats treat even distal stimuli in a CS sequence as immediately relevant to food, not conditional on an intermediate stimulus. These results urge caution in representing indirect associations as conditional associations, accentuate the theoretical weight of the Markov condition in graphical models, and challenge theories to articulate the conditions under which animals are expected to learn conditional associations, if ever.All funding for the project was internal, from Indiana University

Operant learning theory in pain and chronic pain rehabilitation

The application of operant learning theory on chronic pain by Fordyce has had a huge impact on chronic pain research and management. The operant model focuses on pain behaviors as a major component of the pain problem, and postulates that they are subject to environmental contingencies. The role of operant learning in pain behaviors generally has been supported by experimental studies, which are reviewed in the present article. Subsequently, the rationale, goals, and methods of operant behavioral treatment of chronic pain are outlined. Special attention is paid to three therapeutic techniques (graded activity, activity pacing, and time-contingent medication management), which are discussed in detail with regard to their operationalization, effectiveness, and (possible) mechanisms of action. Criticisms of the operant model are presented, as are suggestions for the optimization of (operant) behavioral treatment efficacy