This study was an investigation of the role of perceptual and functional features in the development of naturally-occurring and artifactual categories. Twenty-five college students, 16 fourth grade students, and 18 second-grade students participated in a sentence verification task. Each subject was presented sentences containing typical and atypical exemplars from naturally-occurring and artifactual categories paired with perceptual and functional features. The subjects were to indicate whether each sentence was true or false. A four-way mixed design ANOVA was performed on response times and error rates. A general developmental trend in category acquisition was indicated by the data. Children first learn typical naturallyoccurring category items. As they grow older, naturally-occurring categories are learned most thoroughly because of their clear-cut membership. Artifactual categories, which are less limited in membership, take longer for children to process. There was no evidence in the data to suggest that the differences between the two category types was due to a perceptual feature basis for naturally-occurring categories.

This thesis examined how task demands shape the category representations formed through classification, inference and incidental learning. Experiments 1 to 3 examined the claim that the representations formed through inference learning are based only on the encoding of prototypical features (e.g., Yamauchi & Markman, 1998, 2000). Adults learned artificial categories through exemplar classification or feature inference. Inference learning either did or did not require attention to prototypical features. At test, all participants classified exemplars and inferred the values of missing features. Classification learning resulted in the encoding of both prototypical and atypical features. Inference learning also led to the representation of both prototypical and atypical features when attention to both was required during learning. Experiment 4 extended these results to inferences about novel items varying in similarity to training items. Inference learners required to attend to prototypical and atypical features during training were more sensitive to exemplar similarity when making novel inferences than those who attended only to prototypical features. Experiment 5 examined developmental change in the impact of noun and feature labels on feature inferences. Adults, 7-year-olds, and 5-yearolds were shown pairs of base and target exemplars. The base was given a noun or feature label. Participants were asked to predict the value of a missing feature of the target, when it was given the same or a different label as the base. Both adults and children were more likely to make inferences based on noun than feature labels. Hence, by five years of age, children grasp the inductive potential of noun labels. Experiments 6 to 9 compared incidental category learning with intentional classification. Adults classified categories of geometric shapes or learned the categories through an incidental task. Incidental recognition learning resulted in a broader allocation of attention than classification learning. Performing recognition before classification resulted in a broader attentional allocation than performing recognition after classification. Together with the results from mathematical modelling, these findings support a view of category learning in which the specific attentional demands of different learning tasks determine the nature of the category representations that are acquired.

Thesis (Ph. D.)--University of California, Santa Cruz, 1993. / Typescript. Includes bibliographical references (leaves 34-35).

Thesis (M.S.)--Villanova University, 2006. / Psychology Dept. Includes bibliographical references.

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published_or_final_version / Psychology / Doctoral / Doctor of Philosophy

All these four factors influence the degree of CP. In the discussion, both general auditory processing and language specific processing are suggested to be responsible for the various types of exhibition of CP, although they have different weights for different factors. Different patterns of CP were also observed in three temporal stages due to different weights of these two types of processing. In summary, a multistage model which includes both general auditory processing and language specific processing is proposed to explain the CP of lexical tones. This model improves previous models by proposing that the weights of these two types of processing in speech perception depend on the types of factors, and the temporal processing stages. / Finally, for the first time in the literature, the thesis also reported that even though a tone contrast (i.e., level vs. rising) is present in both tone systems, the same contrast is perceived differently by the two groups of subjects by virtue of their different language experiences. / Four factors were studied. They were (1) intrinsic acoustic properties of pitch contours by comparison between continua of level tones and contour tones; (2) positions of target syllables relative to context (without contextual sentence, at the beginning and at the end of the contextual sentence); (3) language backgrounds by comparison between listeners with different tone experiences; and (4) carrier syllables (real word, non word, and nonspeech). Three temporal stages were studied in the same experimental paradigm. They were (1) the preattentive stage investigated through the mismatch negativity (MMN); (2) the attentive stage investigated through the P300; and (3) the overt response stage investigated through the hit rate data. / Pitch contour or its acoustic correlate, fundamental frequency (F0), distinguishes lexical meanings in tone languages. Two topics on CP of lexical tones were studied in the thesis: (1) the factors influencing CP, and (2) the temporal process of CP. These two topics were investigated through both behavioral and event-related-potential (ERP) methods on Cantonese and Mandarin tones. / Speech sounds vary across different conditions and subjects; nevertheless, listeners perceive the phonemes without difficulties. Categorical perception (CP) occurs when listeners map the varying speech sounds into discrete phonemic categories. In CP, to discriminate a pair of stimuli that cross a category boundary is much easier than those that lie within the same category, even though both pairs are separated by an equal physical difference. CP is one of the important properties essential for speech perception. / Zheng, Hongying. / Adviser: William Shi-Yuan Wang. / Source: Dissertation Abstracts International, Volume: 72-04, Section: A, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 179-194). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese; appendix 2 in Chinese.

Graduation date: 1996

Thesis (M.A.)--Miami University, Dept. of Speech Pathology and Audiology, 2002. / Title from first page of PDF document. Document formatted into pages; contains ix, 86 p. Includes bibliographical references (p. 69-75).

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