Abstract

The primary objectives for this experiment were to analyze the neuroanatomical correlates of autobiographical, episodic and semantic memory, use a different paradigm to promote episodic memory retrieval, and employ a different analysis technique to understand retrieval processes. Autobiographical and episodic memories are personal memories from the past. Autobiographical is more general (e.g. a street name of a house growing up) and episodic is more specific to time (e.g. 13th birthday party that took place on a street). For autobiographical and episodic memory retrieval operations, there is no general consensus as to the localization of function, but bilateral activation of the frontal and temporal lobes, in addition to the parietal lobe, are most frequently cited in the literature. In contrast to autobiographical and episodic memories, semantic memory is for general, factual knowledge that is not tied to a specific time and place. For semantic memory retrieval operations, the general consensus is that left hemisphere structures, including the left frontal lobe and left temporal lobe, are predominately active. However, the extent to which each structure is involved in retrieval has not been explained. This may be better understood by providing precise numeric values to cortical activity, thereby allowing more statistical analysis and comparison of the processing conditions. Fourteen participants were included in the analysis. Data were recorded from a whole-cortex 68-channel MEG system. The experiment had two stages: study phase (semantic / perceptual decisions) and recognition phase (autobiographical / episodic / semantic decisions). Data (percentage of cortical activity, amplitude) were acquired during the recognition phase. Repeated measures ANOVAs were used to compare both neuroanatomical location and amplitude of event-related-fields. For the neuroanatomical data, the analyses revealed significant main effects for lobe, hemisphere, condition, and epoch, but no significant interactions. For the amplitude data, the analyses revealed significant main effects for lobe, condition, and epoch, but not for hemisphere. There were also several significant interactions. The results of this experiment provided information regarding two main topics. First, whether or not the hippocampal complex plays a role in the retrieval of episodic memories. These results may provide support for the role of the hippocampal complex in episodic memory retrieval. Second, semantic and episodic memory may be thought of as a continuum because all semantic memories start as episodic memories. The context of a learning experience is always present, at least at the beginning, when retrieving a memory. Therefore, it is difficult to distinguish semantic from episodic memory because both entail characteristics of the other.

LLU Discipline

Experimental Psychology

School

Graduate Studies

First Advisor

Richard Hartman

Second Advisor

William Sutherling

Third Advisor

Mary-Catherin Freier

Fourth Advisor

Jason Owen

Fifth Advisor

Linda Philpott

Degree Name

Doctor of Philosophy (PhD)

Degree Level

Ph.D.

Year Degree Awarded

2007

Date (Title Page)

6-2007

Language

English

Library of Congress/MESH Subject Headings

Memory -- physiology; Brain; Neuropsychology; Memory Disorders; Repression, Psychology.

Type

Dissertation

Page Count

xv; 115

Digital Format

PDF

Digital Publisher

Loma Linda University Libraries

Usage Rights

This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.

Collection

Loma Linda University Electronic Theses and Dissertations

Collection Website

http://scholarsrepository.llu.edu/etd/

Repository

Loma Linda University. Del E. Webb Memorial Library. University Archives

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