Thesis (M.A.) - Simon Fraser University, 2005. / Theses (Dept. of Psychology) / Simon Fraser University. Also issued in digital format and available on the World Wide Web.

Here we examined hemispheric differences in conscious and nonconscious perception using a masked priming paradigm. In Experiment 1, participants judged the direction of a grey target arrow (either left- or right-pointing), which was preceded by a grey prime arrow in either the left visual field (LVF)/right hemisphere (RH) or the right visual field (RVF)/left hemisphere (LH). The prime was either masked or unmasked. Participants reported unaware of the prime in the masked condition. We found a significant congruency effect (i.e., a faster response when the prime and target directions were congruent than when they were incongruent) when the prime was presented in the LVF/RH but not the RVF/LH in the masked (subliminal) condition. In contrast, in the unmasked (supraliminal) condition, the RVF prime had a stronger congruency effect than the LVF prime. In Experiment 2, a backward mask was used in all trials and the prime duration was manipulated to create subliminal and supraliminal conditions. In the subliminal condition, LVF/RH primes but not RVF/LH primes generated a congruency effect, whereas in the supraliminal condition, RVF/LH primes had a bigger congruency effect than LVF/RH primes. These qualitatively different hemispheric asymmetry effects in Experiment 1 and 2 suggest that nonconscious and conscious perception may involve different underlying mechanisms. In Experiment 3, color stimuli instead of grayscale stimuli were used. Neither the congruency effect nor the LVF/RH advantage was found in the subliminal condition, while a similar RVF/LH advantage in the congruency effect was found in the supraliminal condition. This result suggests that parvocellular input does not support the subliminal priming effect in the LVF/RH. Taking together, our results revealed a dissociation between the mechanisms underlying nonconscious and conscious processing, and this dissociation may be due to the dominant role of the magnocellular pathway in nonconscious vision. / published_or_final_version / Psychology / Master / Master of Philosophy

This study investigates the reproductive and parental roles of polyandrous male pale chanting-goshawks, Melierax canorus, and speculatively reviews the fitness outcomes of different skew and relatedness scenarios. The study was conducted over five years in the Little Karoo, South Africa. Although, polyandrous males participated equally in building nests, provisioning prey and incubating, in the fertility window the dominant alpha males copulated 31–5 days before the females laid, whereas subordinate beta males only copulated 5–3 days before laying. If this copulation timing by alpha males was indicative of a high reproductive skew, alpha males breeding as full sibs could skew paternity in their favour (ratio 68:32) and produce 0.69 offspring equivalents. Under this scenario, they compensated beta males with indirect fitness benefits by allowing them to produce 0.54 offspring equivalents, equal to monogamous males. Alternatively, if beta males controlled reproduction while breeding with non-relatives under a high skew scenario, they would have to restrain themselves to avoid eviction and produce 0.28 offspring equivalents to allow the fitness of alpha males at least to equal that of monogamous males. I suggest that alpha males and their females altered their reproductive roles to accommodate beta males, thereby increasing their inclusive fitness, whereas beta males tolerated subordination to acquire reproductive skills that non-breeder males do not have access to.

published_or_final_version / abstract / toc / Clinical Psychology / Master / Master of Social Sciences

Thesis (Ph.D.)--Bowling Green State University, 2007. / Document formatted into pages; contains xii, 223 p. Includes bibliographical references.

Thesis (Ph. D.)--University of California, San Diego, 1999. / Vita. Includes bibliographical references (leaves 171-178).

Thesis (M.A.)--West Virginia University, 1999. / Title from document title page. Document formatted into pages; contains v, 57 p. Includes abstract. Includes bibliographical references (p. 33-35).

Thesis--University of Florida. / Description based on print version record. Typescript. Vita. Bibliography: leaves 89-102.

Thesis (M.A.)--York University, 2007. Graduate Programme in Psychology. / Typescript. Includes bibliographical references (leaves 113-123). 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:MR38827

Thesis (M.S.)--University of Wisconsin--Madison. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 53-61).