Date of Award
Doctor of Philosophy in Psychology
Theoretically, predictive cues have a major role in conditioning. Both conditional stimuli and operant responses function in a way which provide information to a subject about what is to occur under a particular set of circumstances. Any available cue will have a particular relationship with any given outcome stimulus (So) based on the probabilities of cooccurrences and non co-occurrences, whereby the resulting predictive value will impact on the behavioral consequences. A stimulus can produce behavioral effects it never caused prior to conditioning. Are those behavioral effects the result of the predictive value of the stimulus alone, or does the motivational value of the stimulus change? Could the resulting behavior be based on some combination of both? The value - both incentive value as well as predictive value - of the predictive cue itself is of significance. Knowing about the manner in which cues are affected will have an effect on how they are used, how they will affect behavior and how they function in applied settings. Despite an abundance of valuable information pertaining to such events, several crucial issues remain to be examined. First, exactly how does the predictive value of the predictive cue influence behavior? Cues which are highly reliable should influence behavior in a very systematic manner. Depending upon the motivational value of the outcome predicted, a consistent approach or withdrawal behavior should be exhibited. Additionally, cues which are unreliable should have less systematic influence on behavior. Since such cues provide no reliable information regarding outcomes, no reliable behavioral consequences should be observed. The present research was designed to separate the predictive and incentive values of the predictive cue itself by examining the behavioral consequences of altering the incentive value of outcome stimuli on the incentive value of the cues that predict them. This design was employed to examine if the relative tendency of the animal to approach or withdraw from any particular predictor changed when the relative tendency to approach or withdraw from the outcome stimulus was altered. The questions specifically investigated were: in regard to a classically conditioned behavioral effect, to what extent does a stimulus retain or take on the initial value of the stimulus it predicts, and to what extent is it based upon the current (altered) value of the stimulus it predicts? The design employed provides a measure of the motivational value of predictive cues relative to the current motivational value of the outcome stimulus. In all circumstances it is the value of the outcome stimulus that was manipulated, while responding to or for the predictive cue (S2) was measured. Thus, the behavioral consequences of the value of outcome stimuli on the value of the predictive cues was assessed. Subjects were 64 male Sprague-Dawley albino rats weighing 250 - 350 gm. All subjects were hungry and thirsty throughout the entire experiment. Subjects were randomly assigned to one of eight groups (eight subjects per group) and run through the sequence of the experiment as determined by the particular group. Group membership is
indicated by a three unit code pertaining to the Sensory Preconditioning Configuration - Sensory Preconditioning Stimulus Presentation - Revaluation phase sequences. For example, subjects in group APL received Sensory Preconditioning Configuration A, Stimulus Presentation P, and Revaluation L. As a result of the above manipulations, the following should be true for both Sensory Preconditioning Configurations: 1) The RN group has no predictive value and provides information regarding the original, unaltered motivational value of S1 and S2. 2) The RL group has no predictive value and provides information regarding the original, unaltered motivational value of S2 and information regarding the devalued motivational value of S1. 3) Group PN evidences the ·predictive value of S2 and the inherent, unaltered motivational value of S1. 4) The PL group provides information regarding the motivational value of S2 after St has been devalued, as well as the devalued motivational value of S1 and the predictive value of S2. A 2x2x2 Multivariate Analysis of Variance (MANOVA) with eight dependent measures (T1P, T1S2, T2S1, T2H2O, T3S2, T3H2O, T4S1, T4S2) was conducted. The MANOVA produced the following results: Configuration (C), F(8,47) = 22.45 , p<.001; Stimulus Presentation (StP), F(8,47) =0.61, n.s.; Revaluation, (R)
F(8,4 7) = 19.54, p<.001; Configuration x Stimulus Presentation, F(8,47) =0.8, n.s.; Configuration x Revaluation, F(8,47) = 10.36, p<.001; Stimulus Presentation x Revaluation, F(8,47) =0.93, n.s.; Configuration x Stimulus Presentation x Revaluation, F(8,47) = 1.32, n.s. Follow-up ANOVAs and Tukeys revealed an unexpected pattern of results. The data suggests that illness is what produced the quinine-water discrimination, but that prior to experiencing the salient contingent event of illness to quinine, water and quinine were not responded to differentially. Such a finding has strong implications for the Sensory Preconditioning phase. Since all animals had access to water in their home cages daily during all phases (except Revaluation and Testing), and were exposed to water in the training apparatus during Acclimation, animals (both Paired and Random) experienced presentations of saccharin and water in a random fashion. In essence, there was no contingent relationship in place for the Paired subjects and results indicate that all subjects responded as if no learning occurred during Sensory Preconditioning. Consequently, no predictive relationship was established so habituation to the taste of saccharin took place. Also, as a result of the absence of this predictive relationship, none of the differential experimental conditions were in place and subjects were unable to predict either the original or altered value of the CS.
Dibiasio, Paige A., "An Analysis of Altering the Value of a Classically Conditioned Predictive Cue" (1992). Open Access Dissertations. Paper 913.