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

Thesis (Ph. D.)--Ohio State University, 2006. / Title from first page of PDF file. Includes bibliographical references (p. 213-226).

Undergraduate honors paper--Mount Holyoke College, 2006. Program in Neuroscience and Behavior. / Includes bibliographical references (leaves 52-57).

Thesis (M.S.)--University of Michigan, 1962.

Thesis (Ph.D.)--York University, 2006. Graduate Programme in Psychology. / Typescript. Includes bibliographical references (leaves 233-251). 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:NR29504

Thesis (M.S.)--West Virginia University, 2007. / Title from document title page. Document formatted into pages; contains vi, 53 p. : ill. Vita. Includes abstract. Includes bibliographical references (p. 50-51).

This thesis is concerned with describing and experimentally investigating the nature of perceptual learning. Ecological psychology defines perceptual learning as a process of educating attention to structural properties of stimuli (i.e., invariants) that specify meaning (i.e., affordances) to the perceiver. Although such definition comprehensively describes the questions of what humans learn to perceive, it does not address the question of how learning occurs. It is proposed in this thesis that the principles of classical and operant conditioning can be used to strengthen and expand the ecological account of perceptual learning. The perceptual learning of affordances is described in terms of learning that a stimulus is associated with another stimulus (classical conditioning), and in terms of learning that interacting with a stimulus is associated with certain consequences (operant conditioning). Empirical work in this thesis investigated the effect of conditioning on pitch and speech perception. Experiments 1, 2, and 3 were designed to modify pitch perception in Shepard tones via tone-colour associative training. During training, Shepard tones were paired with coloured circles in a way that the colour of the circles could be predicted by either the F0 (pitch) or by an F0-irrelevant auditory invariant. Participants were required to identify the colour of the circles that was associated with the tones and they received corrective feedback. Hypotheses were based on the assumption that F0-relevant/F0- irrelevant conditioning would increase/decrease the accuracy of pitch perception in Shepard tones. Experiment 1 investigated the difference between F0-relevant and F0- irrelevant conditioning in a between-subjects design, and found that pitch perception in the two conditions did not differ. Experiments 2 and 3 investigated the effect of F0- relevant and F0-irrelevant conditioning (respectively) on pitch perception using a within subjects (pre-test vs. post-test) design. It was found that the accuracy of pitch perception increased after F0-relevant conditioning, and was unaffected by F0-irrelevant conditioning. The differential trends observed in Experiments 2 and 3 suggest that conditioning played some role in influencing pitch perception. However, the question whether the observed trends were due to the facilitatory effect of F0-relevant conditioning or the inhibitory effect of F0-irrelevant conditioning warrants future investigation. Experiments 4, 5, and 6 were designed to modify the perception of McGurk syllables (i.e., auditory /b/ paired with visual /g/) via consonant-pitch associative training. During training, participants were repeatedly presented with /b/, /d/, and /g/ consonants in falling, flat, and rising pitch contours, respectively. Pitch contour was paired with either the auditory signal (Experiments 4 and 5) or the visual signal (Experiment 6) of the consonant. Participants were required to identify the stop consonants and they received corrective feedback. The perception of McGurk stimuli was tested before and after training by asking participants to identify the stop consonant in each stimulus as /b/ or /d/ or /g/. It was hypothesized that conditioning would increase (1) /b/ responses more in the falling than in the flat/ rising contour conditions, (2) /d/ responses more in the flat than in the falling/ rising contour conditions, and (3) /g/ responses more in the rising than in the falling/flat contour conditions. Support for the hypotheses was obtained in Experiments 5 and 6, but only in one response category (i.e., /b/ and /g/ response categories, respectively). It is suggested that the subtlety of the observed conditioning effect could be enhanced by increasing the salience of pitch contour and by reducing the clarity of auditory/visual invariants that specify consonants. / Doctor of Philosophy (PhD)

Crickets provide a useful model system to study how animals analyze sound frequency. While much is known about how sound frequency is represented by central neurons and in behavior, little is yet known about auditory receptor neurons. I investigated physiological and anatomical properties of auditory receptor fibers (ARFs) and functional organization of their axon terminals, using single-unit recording and staining techniques. Behavioral experiments suggest that crickets are sensitive to two broad frequency ranges, centered at 4--5 kHz for acoustic communication and at 25--50 kHz for predator detection. However, cricket ARFs fall into three distinct populations, based on characteristic frequency (CF; low frequency, ∼3--5.5 kHz; mid frequency, 9--12 kHz; ultrasound, ≥18 kHz). One striking characteristic of single ARFs is the occurrence of multiple sensitivity peaks at different frequencies, which implies that the wide audible range of crickets is mediated by these multiple sensitivity peaks, even though CFs of ARFs are clustered at the three small ranges. To understand how populations of ARFs code sound intensity, level-response functions are examined. Physiological parameters derived from level-response functions are diverse, and are systematically related to threshold within each population. Low-frequency ARFs comprise two distinct anatomical types, based on the distributions of axon terminals, which also differ physiologically. Thus, based on CF and anatomy, cricket ARFs can be classified into four distinct populations. To understand how information flows from peripheral to central neurons, the positions of varicosities, i.e. output sites, of ARF axon terminals are mapped on a two-dimensional coordinate system. In crickets, the ARF axon terminals are functionally organized with respect to frequency and intensity. Anatomical organization with respect to threshold is related to physiological organization, which may reduce non-linear effects in postsynaptic

Thesis (M.S.)--University of Michigan, 1965.

Thesis (M.S.)--University of Michigan, 1965.