Author

Lora L. Sloan

Date of Award

12-1997

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Psychology

First Advisor

Dr. Thomas Petros

Abstract

Depressed individuals have been found to exhibit memory deficits on tasks that require effortful processing. They have also been found to remember negative materials better than their nondepressed cohorts. While these findings are well-documented, there have been few studies designed to examine how and why these differences in recall occur. The present study examined prose passage and word list recall in depressed and nondepressed college students. Processing times and structure of recall were also examined to assist in determining how material was processed and remembered. Half of the passages and word lists utilized were of negative affective valence and half were of neutral affective valence. Subjects were 70 undergraduate students who completed the Beck Depression Inventory (BDI) and Geriatric Depression Scale (GDS) prior to selection and again at the time of participation to ensure stability of mood. Individuals scoring at or above 10 on the BDI and at or above 11 on the GDS during both screening and experimental phases were classified as depressed. Individuals scoring at or below four on the BDI and at or below four on the GDS during both screening and experimental phases were classified as nondepressed. Subjects read narrative passages and word lists from a computer screen. Rate of presentation was controlled by subjects and recorded in milliseconds by the computer. Oral recall was audiotaped immediately after each story or word list. Memory for each passage was expressed as the proportion of idea units recalled at each of three levels of importance. Prose passage recall analyses indicated that depressed subjects remembered more idea units from negative passages than neutral passages and exhibited superior recall to nondepressed subjects for negative word lists. Memory for each word list was expressed as the proportion of idea units recalled at each of three serial positions. Word list recall results revealed that nondepressed subjects recalled significantly more neutral words than negative words and demonstrated superior recall to depressed subjects for neutral word lists. Structure of recall and processing time did not vary between groups on either task despite differences in memory performance. Results indicated a mood congruent memory bias for both prose passages and word lists. The group exhibiting the mood congruent memory bias changed with task, however. The reason for the difference in the pattern of memory bias between the prose and word list recall tasks is not immediately obvious but may be the result of a differential degree of effortful processing required when processing word lists and prose passages. The implications of these findings in relation to models of cognitive processing in depression are discussed.

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