No description available.

Call number: LD2668 .T4 1962 A39

Call number: LD2668 .T4 1966 H263 / Master of Science

No description available.

Separate groups of rats were trained to enter one arm of a Y-Maze for food. They were then exposed to footshock, cues previously paired with footshock (CS), or neutral cues. When tested on the Y-Maze 24 hours later, rats that received post-training shock exhibited improved performance compared to rats that received no shock. Immediate post-training CS exposure improved performance compared to rats that were previously shocked but exposed to neutral cues as the post-training treatment. Delayed (2 hours) post-training presentation of the CS did not improve Y-Maze performance compared to immediate post-training presentation of the CS. Post-training exposure to the individual CSs (context or tone) improved Y-Maze performance relative to the neutral cues but not to the combination of cues. / Conditioned freezing and place avoidance in the presence of the CS were two other conditioned responses measured. No correlation was found between any of the responses measured. These findings suggest that conditioned "fear" (an internal affective state) may function independently from observable behavioral measures.

No description available.

The purpose of this study is to clarify and accurately describe the interactive effects of several amounts of reward and delay on acquisition and extinction or rats in a straight runway. A factorial study involving several levels of reward and delay is presented to further describe and possibly predict what effects these independent variables have on learning curves. The major purpose of this paper, then, is to determine the interactive effects of delay and magnitude of reward, and to present the results in a clarifying and informative manner.

No description available.

The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on January 22, 2010). Thesis advisor: Dr. Marjorie Skubic. Includes bibliographical references.

The experiments reported in the present thesis investigated the effects of lesions to the anterior nuclei of the thalamus (ATN) on the acquisition of two spatial, working memory tasks performed on the eight-arm radial maze. In the task used in Experiment 1 and 2, the animals were required to discriminate and remember all the eight arms of the maze simultaneously. Lesions of the ATN produced impairments in the acquisition of this task, but the degree of impairment depended on the amount of damage within this region. In the task used in Experiment 3, the animals were required to discriminate and remember only two arms at once. Lesions of the ATN were shown to impair its acquisition even though performance was facilitated by the addition of visual intra-arms cues. These experiments suggest that the ATN may be involved in spatial learning and in the retention of non-specific information over time.