Trial lecture title: "A comparison of the concepts of overshadowing and blocking."
Ordinary opponents:
- First opponent: David Palmer, Senior Lecturer Emeritus in Psychology/PhD, Smith College, USA
- Second opponent: Anna Ingeborg Petursdottir, Associate Professor/PhD, Texas Christian University, USA
- Leader of the evaluation committee: Associate Professor Torunn Lian, Faculty of Health Sciences, OsloMet
The leader of the public defense is Head of Studies Ingunn Sandaker, OsloMet
The main supervisor is Professor Per Holth, OsloMet. The co-supervisor is Professor Espen Borgå Johansen, OsloMet.
Thesis abstract
For some individuals with developmental disabilities, a limited range of interests, reinforcing stimuli and events is one of the common characteristics. Finding the best ways of conditioning new reinforcers for such individuals may promote the development of new skills and increased social interaction.
The concept of conditioned reinforcement has played an essential role in the development of behavior analytic procedures to improve behavioral control. Conditioned reinforcement has been frequently investigated and reviewed, and more recently, with a growing interest from applied researchers.
The customary procedures to establish conditioned reinforcers have been through stimulus–pairings, rooted in the principle of respondent conditioning, or by establishing a previously neutral stimulus as a discriminative stimulus through operant discrimination training. Stimulus-pairing procedures have usually been conducted either response-independent or response-contingent, individually reported with inconclusive results.
Both basic and applied research on the standard procedures have been affected by a variety of variables and inconclusive results, which make it hard to identify the most effective means to establish conditioned reinforcers. This prompted us to use an animal model for applied research questions on how to establish conditioned reinforcers.
Study 1
In Study 1, operant discrimination training (ODT) was compared to response-independent stimulus–stimulus pairing (SSP), in rats.
The ODT procedure was demonstrated to be the most effective of the two to establish conditioned reinforcers.
Study 2
Study 2 investigated whether blocking of stimulus control would extend to blocking of conditioned reinforcers also, and the results from the experiments in the study showed blocking of stimulus control in addition to blocking of the conditioned reinforcing effect of stimulus used in a standard blocking procedure.
Study 3
Study 3 aimed to replicate an applied study where the effect of response-contingent stimulus–pairings (RSSP) was compared to response-independent stimulus–pairings (SSP).
No effect was found in any of the procedures, contrary to several of the applied studies.
The three studies in this thesis focused on different issues but taken together a recommendation is to use response-contingent procedures, preferably by establishing stimuli as discriminative to most effectively establish conditioned reinforcers. Still, basic and applied complementary work is required to continue to meet significant applied needs.
