Psychology ETDs

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An experiment was conducted investigating the role of distinctive verbal labels and scaled stimulus codability on the temporal course of recognition memory for complex random shapes. Three between-S variables, delay interval, pretraining type, and stimulus codability, were combined with one within-S variable, stimulus exposure duration, into a 3x2x2x(2) factorial design. Subjects were given observation or relevant verbal label pretraining with either high or low codability stimuli and were subsequently tested on a five-stimulus forced-choice recognition task either immediately, 15 minutes, or 1 week after training. All subjects saw one half of the stimuli for their condition for 6.0 seconds on each of four exposures and the other half for 0.5 seconds on each exposure. An experimental design suggested by Daniel (1968) was employed in order to control for the loss of subjects which frequently arises in the context of experiments employing long-term delays.

Although the findings of early research in memory for form suggested that the length of temporal delay should affect memory for shape stimuli, one of the most outstanding features of the findings reported in the present experiment was the stability of recognition memory over the delay intervals investigated. Both high stimulus codability and verbal label pretraining resulted in superior recognition performance, but the effects of these variables were not found to be influenced by the level of post-predifferentiation delay. Recognition performance was also consistently superior for stimuli exposed for 6.0 seconds in pretraining as compared to those exposed for 0.5 seconds.

Two tentative explanations for the data are discussed, one employing an hypothesis derived from the interference theory of forgetting and the other based on implications of recently developed models of human form perception which emphasize the role of verbal encoding processes in perception and memory for form. It was concluded that these explanations were only tentative because of a lack of experimental evidence in the first, interference theory, account and due to the fact that specific implications of the verbal coding models for long-term memory of complex shapes have not been systematically formulated.

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First Committee Member (Chair)

Henry Carleton Ellis

Second Committee Member

Frank Anderson Logan

Third Committee Member

David Theodore Benedetti

Fourth Committee Member

Peder Jack Johnson



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Psychology Commons