Three experiments were performed to test the influences of both the similarity relations in the stimulus set and of the prototypicality of stimulus items on response times to pairs of words. In the first experiment, subjects judged word pairs from six natural semantic categories as containing members from the same category or from different categories. Pairs of both high and low typicality were primed by items of their own or of a different typicality which were similar or dissimilar to the pairs. The effects of prime -pair relations on reaction times were analyzed. It was found, for both the prime types used in earlier work by Rosch and by Evans and Lockhead and for prime types new to this experiment, that a prime similar to a SAME pair produced faster responses to that pair than did a prime dissimilar to the pair, even when the prime -pair typicality match was controlled. In addition, responses to DIFFERENT pairs were shown to be significantly influenced by the similarity relations of the categories involved in the pairs. In the second experiment, three of the cultural categories from Experiment 1 were reexamined, with the special purposes of testing category differences in priming effects and of evaluating the influence of practice on priming results. The general pattern of response times obtained in Experiment 2 replicated the results of the first study: Prime-pair similarity was shown to influence reaction times importantly. With respect to category differences, it was demonstrated that response speeds were inversely related to the similarity between categories in the experimental set: When the category(s) from which the pair items came were distinctive in the total set, the average SAME and DIFFERENT responses to that pair were fast. No other important category differences were obtained. Finally, it was shown that there was some decrease in differential priming effects in these natural semantic categories very early in practice. In Experiment 3, the similarity relations of the primes and pairs used as stimuli in the two earlier studies were evaluated. Also, the correlations of the rated prime and pair similarities and the pair response times obtained in Experiment 1 were computed. It was shown that similarity was significantly related to both SAME and DIFFERENT reaction times: For SAME pairs, the more similar a prime was to a pair, the faster were the SAME responses to that pair; for DIFFERENT pairs, the more dissimilar were the categories involved in the pair, the faster were the DIFFERENT responses to that pair. These three studies demonstrated that the similarity relations within and between natural categories importantly affect category decisions in a priming paradigm. It is suggested that the role of the natural prototype in such categories can be interpreted in terms of the more general similarity structure of the category space. / This thesis was digitized as part of a project begun in 2014 to increase the number of Duke psychology theses available online. The digitization project was spearheaded by Ciara Healy.

Thesis (M.A.)--Miami University, Dept. of Psychology, 2003. / Title from first page of PDF document. Document formatted into pages; contains v, 20 p. Includes bibliographical references (p. 19-20).

No description available.

Thesis (Ph. D.)--UCLA, 2008. / Vita. Description based on print version record. Includes bibliographical references (leaves 113-116).

Category learning is an essential cognitive function. Empirical evidence and theoretical reasons suggest existence of multiple dissociable category learning systems. Here, a proposal is made that different category learning tasks are dominated by different category learning systems. A dual system theory of category learning COVIS proposes dissociation between an explicit, hypothesis-testing system, and an implicit, procedural learning system. Two studies testing this dissociation are presented, supporting the notion that hypothesis testing, utilizing working memory and explicit reasoning, mediates learning in rule-based tasks, while gradual and automatic S-R learning mediates information-integration tasks. Inconsistent findings in the literature regarding a prototype learning task suggest that two versions of this task, the A/nonA, single prototype task and the A/B, two prototype task, are mediated by distinct category learning mechanisms. A novel methodology for studying the A/nonA task and the A/B task is proposed and utilized in a functional magnetic resonance imaging study. The study reveals that the A/B task is mediated by declarative memory while the A/nonA task is mediated by perceptual learning. We conclude that at least four category learning systems exist, based on four memory systems of the brain: working memory, procedural memory, declarative memory and perceptual memory. The four category learning systems compete or cooperate during learning, each system dominating in a different category learning task. Category learning tasks provide a useful tool to understand learning and memory systems of the brain. / text

published_or_final_version / Psychology / Master / Master of Philosophy

The roles of independent and correlated properties in real world object concepts were explored. Property norms were collected for 190 natural kinds and artifacts. The norms were used to design behavioral experiments and computational models of concept similarity. Property intercorrelations influenced performance in property verification. Concept similarity, as measured by overlap of independent properties, predicted similarity ratings, speeded same/different category decision latency, and short interval priming latency. Concept similarity, as measured by overlap of correlated properties, predicted same/different category decision latency and short interval priming for natural kinds. It was concluded that people encode knowledge about independent and correlated properties of real-world objects. The influence of property intercorrelations is stronger for natural kinds because natural kinds contain a higher proportion of correlated properties. In the investigation of short interval semantic priming, results suggested that semantic relatedness can be defined in terms of property overlap between concepts.

Thesis (M.A.)--York University, 2006. Graduate Programme in Psychology. / Typescript. Includes bibliographical references (leaves 73-78). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR19739

Thesis (M. S. in Psychology)--Vanderbilt University, Dec. 2008. / Title from title screen. Includes bibliographical references.

Thesis (Ph. D.)--UCLA, 2007. / Vita. Includes bibliographical references (leaves 88-97).