Publication Date


Document Type


First Advisor

Doty, Larry A.||Gorry, Thomas

Degree Name

M.A. (Master of Arts)

Legacy Department

Department of Psychology


Goldfish; Memory


Recent evidence indicates that long-term memory consolidation is dependent upon nonreversable molecular changes within the central nervous system. It has been demonstrated that this biosynthetic process can be inhibited by secondary stimuli associated with a conditioning situation. The purpose of this research was to determine and compare the relative consolidation or inhibitory properties of stimuli associated environments and secondary stimulation which was not previously associated with the conditioning environment. It is hypothesized that the general stimulation level of the postconditioning environment has reactive inhibitory properties of greater proportions than the stimulation associative value of the conditioning environment, and that these two factors are related. Sixty common goldfish, Carassius auratus, were randomly distributed in a 2 x 2 x 3 factorial design. Two post-conditioning environments (stimulation associated and not stimulation associated), two levels of post-conditioning stimulation (high and normal), and three post-conditioning environment treatment groupings (puromycin inject, placebo inject, and noninject) made up the treatment combinations. All animals were conditioned over twenty escape- avoidance trials utilizing a shuttlebox modified after Homer, Longo, and Bitterman (1961). Each subject was then placed in the post-conditioning treatment, determined by its grouping, where it remained for one hour. At the end of this period, further consolidation was inhibited by an injection of puromycin into the cerebral cavity in the experimental group, or a placebo injection administered to the first control group, while a second control group received no injection. Seventy-two hours later, all subjects were returned to the shuttlebox and their performance over 20 trials, identical to the first set of trials, was recorded. An analysis of the resulting savings scores indicates that long-term memory is inhibited by secondary stimuli or cues not directly involved in the conditioning paradigm, but, secondary stimuli not associated with the conditioning environment were demonstrated to inhibit long-term memory consolidation when administered to an organism while in a nonstimulation associated environment. These same stimuli were shown to enhance a consolidation when the organism was in a high stimulation associated environment.


Includes bibliographical references.||Includes illustrations.


51 pages




Northern Illinois University

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