Learned changes in the sensitivity of stimulus representations: Associative and nonassociative mechanisms

Central to associative learning theory is the proposal that the concurrent activation of a pair of event representations will establish or strengthen a link between them. Associative theorists have devoted much energy to establishing what representations are involved in any given learning paradigm and the rules that determine the degree to which the link is strengthened. They have paid less attention to the question of what determines that a representation will be activated, assuming, for the case of classical conditioning, that presentation of an appropriately intense stimulus from an appropriate modality will be enough. But this assumption is unjustified. Ipresent the results of experiments on the effects of stimulus exposure in rats that suggest that mere exposure to a stimulus can influence its perceptual effectiveness—that the ability of a stimulus to activate its representation can be changed by experience. This conclusion is of interest for two reasons. First, it supplies a direct explanation for the phenomenon of perceptual learning—the enhancement of stimulus discriminability produced by some forms of stimulus exposure. Second, it poses a theoretical challenge in that it seems to require the existence of a learning mechanism outside the scope of those envisaged by current formal theories of associative learning. I offer some speculations as to how this mechanism might be incorporated into such theories.     

Analysis of the learned irrelevance effect in appetitive Pavlovian conditioning

In Experiments 1 and 2 rats received uncorrelated presentations of a light conditioned stimulus (CS) and a food unconditioned stimulus (US) on each day of a preexposure phase. Control subjects received the same number of USs during the first half of preexposure and the same number of CSs during the second. Uncorrelated preexposure retarded inhibitory conditioning. Experiment 3 showed, however, that the different patterns of US preexposure experienced by the two groups could in itself influence the course of subsequent inhibitory conditioning. When this factor was equated by restricting the uncorrelated treatment to the first half of the pre-exposure phase (Experiment 2) or by extending the control treatment throughout the phase (Experiment 4) it was found that uncorrelated preexposure retarded excitatory conditioning, but facilitated inhibitory conditioning. This outcome challenges an interpretation in terms of the concept of learned irrelevance, which predicts that uncorrelated preexposure should retard both forms of conditioning.     

The Hall index of mystical spirituality: an exploration in constructing a short scale of mystical spirituality

ABSTRACT

The aim of this study was to propose a new nine-item measure of mystical spirituality which would be [as easy as possible] for “ordinary” people (those with little or no theological education) to complete. The measure was developed and tested on data provided by 602 participants within an on-line survey. The Hall Index of Mystical Spirituality displayed excellent properties of internal consistency reliability (reporting an alpha coefficient of .93) and good construct validity, in terms of its location within the four components of psychological space, defined by psychological type theory (reporting a correlation of .30 within the measure of intuition). As a new measure of mystical spirituality further research is needed to test the usefulness of this short scale.     

Domain effects in lexical development: learning words for foods and toys

We investigated 3-year-olds’ and adults’ use of domain cues in learning words for solid and nonsolid material entities. In Experiments 1 and 2, participants heard a novel neutral noun (e.g., “my X”) for a standard solid or nonsolid entity described as either a toy or a food. They then were asked to extend the word to one of two other entities. Both options matched the standard in solidity; but one differed from it in an object-relevant property (shape) and the other in a substance-relevant property (color, texture, or smell). Both children and adults were more likely to select the same-shaped entity if the standard was (1) solid than if it was nonsolid, and (2) described as a toy than if it was described as a food. Their interpretations of novel words for material entities were thus affected not only by perceptual information (about solidity) but also by conceptual information (about domain). In Experiment 3, the novel noun was presented in a syntactic context that suggested the solid entity should be interpreted as an object (e.g., “an X”) and that the nonsolid entity should be interpreted as a substance (e.g., “some X”). For adults, these changes largely eliminated the effect of the entity’s domain (toy, food) on interpretation. We interpret these findings in terms of the proposal that domain cues, like solidity cues, furnish information about whether an entity’s structure should be thought of as arbitrary or nonarbitrary and, hence, about whether a word should be interpreted as naming an object or a substance construal.