abstract: Three experiments used a spatial serial conditioning paradigm to assess the effectiveness of spatially informative conditioned stimuli in eliciting tracking behavior in pigeons. The experimental paradigm consisted of the simultaneous presentation of 2 key lights (CS2 and CTRL), followed by another key light (CS1), followed by food (the unconditioned stimulus or US). CS2 and CTRL were presented in 2 of 3 possible locations, randomly assigned; CS1 was always presented in the same location as CS2. CS2 was designed to signal the spatial, but not the temporal locus of CS1; CS1 signaled the temporal locus of the US. In Experiment 1, differential pecking on CS2 was observed even when CS2 was present throughout the interval between CS1s, but only in a minority of pigeons. A control condition verified that pecking on CS2 was not due to temporal proximity between CS2 and US. Experiment 2 demonstrated the reversibility of spatial conditioning between CS2 and CTRL. Asymptotic performance never involved tracking CTRL more than CS2 for any of 16 pigeons. It is inferred that pigeons learned the spatial association between CS2 and CS1, and that temporal contingency facilitated its expression as tracking behavior. In a third experiment, with pigeons responding to a touchscreen monitor, differential responding to CS2 was observed only when CS2 disambiguated the location of a random CS1. When the presentation location of CS1 was held constant, no differences in responding to CS2 or CTRL were observed. / Dissertation/Thesis / M.A. Psychology 2011

Pigeon's working memory for event duration was investigated using variations of the delayed matching to sample procedure. When a retention interval of variable length was interposed between the sample and comparison stimuli, pigeons responded as though a long-duration sample had been short after retention intervals of 10 sec or greater. This "choose short" effect occurred reliably in each subject, regardless of whether the subject was naive or experienced, whether the sample durations were represented by food-access or light, or whether a two- or three-choice procedure was used. In order to account for these findings, a "subjective shortening" model of memory for event duration was proposed. According to the model, the choose short effect is produced by a discrepancy between a relatively static reference memory of the sample durations and a dynamic working memory of the sample durations that "shortens" over the retention interval. This discrepancy produces the tendency to respond as though the long sample was short, A number of predictions, derived from the subjective shortening model, were confirmed in subsequent experiments. First, after a long retention interval, the point of subjective equality between the short and long samples shifted to a longer duration. Second, stepwise increases in the retention interval produced a temporary choose short effect, whereas stepwise decreases in the retention interval produced a temporary choose long effect. Third, with extended training at a given retention interval, the choose short and choose long effects diminished and overall accuracy improved. These results provided strong support for the subjective shortening model, whereas they could not be interpreted readily within the context of other conceptualizations of working memory processes. / Arts, Faculty of / Psychology, Department of / Graduate

When discriminated IRT procedures have been used to determine preference relations among temporally extended operants, deviations from predictions of the matching law have been found (Hawkes and Shimp, 1974). Using a yoked-control procedure, the present study shows that keypecking in the discriminated IRT procedure has two sources of strength, that arising from the stimulus-reinforcer contingency and that arising from the response-reinforcer contingency Three out of four yoked birds autoshaped to the keylight, and all lead birds showed evidence of control by the keylight under some conditions. As any control of keypecking by the keylight, either discriminated or autoshaped, contributes to deviations from matching, the discriminated IRT procedure does not permit one to draw strong conclusions about preference relations among IRTs.

Typescript. Includes vita and abstract. Bibliography: Includes bibliographical references (leaves 63-68). Description: viii, 68 leaves : map ; 29 cm. / The ability of the Pigeon Guillemot Cepphus columba to rear an additional chick was tested by manipulating clutch sizes. The effect of the manipulations on growth, and hatching, fledging, and egg success was measured in chicks from experimental, natural, and control nests. No significant differences were observed between the nest types. Data from 1983, 1984, 1985, and 1989 were analyzed for potential differences in reproductive success of one and two egg clutches. The ratio of one to two eggs was significantly higher in 1985 and 1989. Hatching and fledging success was significantly higher for two egg clutches in 1985 and 1989. No significant differences were observed for egg success. Egg volume was significantly greater in two egg clutches in 1983 and 1984. Egg volume was correlated with fledging but not with hatching success.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Reproduction de : Thèse d'exercice : Pharmacie : Nantes : 2009. / Bibliogr.

Thesis (Ph. D.)--West Virginia University, 2002. / Title from document title page. Document formatted into pages; contains vi, 85 p. : ill. Includes abstract. Includes bibliographical references (p. 78-85).

Thesis (M.A.)--University of North Carolina at Wilmington, 2003. / Includes bibliographical references (leaves : 85-91).

Thesis (M.A.)--West Virginia University, 2001. / Title from document title page. Document formatted into pages; contains vi, 31 p. : ill. Includes abstract. Includes bibliographical references (p. 30-31).

Thesis (Ph. D.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains vii, 98 p. : ill. Includes abstract. Includes bibliographical references (p. 88-98).