Thesis (M.A. in Psychology)--Vanderbilt University, Aug. 2001. / Title from title screen. Includes bibliographical references.

The primary aim of this study was to investigate source memory performance in individuals diagnosed with Parkinson's disease (PD). The secondary goal was to explore how memory was impacted when subjects were asked to generate responses during encoding. Fifty idiopathic PD patients and fifty healthy control subjects completed a task measuring item memory and source memory which also included a generation manipulation. Relative to controls, PD patients exhibited deficits in source memory but not item memory. Both groups demonstrated enhanced memory performance in the generative condition of the item memory task. The PD group displayed a marginally significant trend toward improvement in source memory when instructed to generate a response. These findings lend support to the notion of a selective pattern of source memory impairment in PD, highlighted by a dissociation between item and source memory performance. Generative tasks may be related to increased activation of key frontal regions that facilitate memory performance. These results could inform new perspectives for cognitive rehabilitation in PD, although further research is necessary.

Time-based prospective memory has been found to be negatively affected by aging, possibly as a result of the declining frontal function that often accompanies aging. In the present study we investigated the role of the frontal lobes in prospective memory. Based upon their scores on a composite measure of frontal function, 32 older adults were characterized as possessing high- or low-frontal function, and were then tested on a time-based laboratory prospective memory task. Overall age effects were also assessed and each of the frontal groups was compared to a group of 32 younger adults. High-frontal functioning participants demonstrated better prospective memory than low-frontal functioning participants, and were not distinguishable from younger adults. The results of this study suggest that it is not aging per se that disrupts prospective memory performance, but it is instead the diminished frontal function seen in a subset of older adults.

In Part I of this thesis, recognition of natural scenes was tested in 72 patients with unilateral frontal- or temporal-lobe excisions and 32 normal control subjects (NC). The occurrence of a novel scene in the midst of a series of other scenes normally induces forgetting of the scene that had preceded the novel one. This phenomenon was not observed following right frontal- and right temporal-lobe lesions, and was only partially present after left temporal-lobe excisions that included the hippocampus (LTH). These brain regions were thus seen as part of a circuit that codes novel stimuli. In Part 2, recall of lists of words was examined in 77 patients and 12 normal control subjects. Both the left frontal-lobe (LF) and LTH groups recalled fewer words overall than the other groups; their performance was normal, however, when the words were pre-organized into categories and when category labels were supplied during test. In another experiment it was demonstrated that the LF group was impaired when category exemplars were provided together with the category labels, the LTH group being unaffected in this condition. It was concluded that left frontal-lobe lesions may affect retrieval mechanisms.

Frontal electroencephalographic (EEG) alpha (α) asymmetry may index the activation of lateralized affect and motivation systems in humans. Resting EEG activation was measured and its relationship to Iowa gambling task (IGT) performance was evaluated. No effects were found for α power asymmetry. However, beta (β) power asymmetry, an alternative measure of resting EEG activation, was associated with the number of risky decisions made in the early portion of the task. Additionally, IGT deck selection patterns suggest there are at least three distinct performance styles in healthy individuals. Interestingly, β power asymmetry contradicts performance predictions based on accepted frontal asymmetry affect and motivation models.

In Part I, recall of spatial location was studied in an incidental-learning situation, where patients with unilateral brain lesions, the amnesic patient, H. M., and normal control subjects were asked to estimate the prices of objects in an array. All patient groups could encode location normally, but patients with right temporal-lobe lesions that included extensive hippocampal removal showed abnormally rapid forgetting. For all groups, and for H. M., location-recall did not differ under automatic and under effortful encoding conditions. It is argued that these results point to the importance of hippocampal-ceocortical interactions in spatial memory. In Part II, patients with frontal-lobe lesions were shown to be impaired in judging the frequency with which words or designs occurred in a list. With words, the deficits were demonstrable for both examiner-provided and self-generated stimuli. This impairment may be attributable either to a disorderly search process or to a deficit in cognitive estimation, or both.

It has been argued that patients with frontal lobe lesions are impaired in temporal context memory and, more generally, in retrieving the source of one's knowledge or ideas. Furthermore, it has been speculated that a failure to retrieve source information may result in an increased susceptibility to distortions of episodic memories in patients with frontal lobe lesions. The precise role of the frontal cortex, however, in source or episodic retrieval is not clear. Does this region of cortex play a primary role or a secondary, executive role in the processing of such memories? Studies of patients with temporal lobe lesions have also shown impairments in episodic memory, including difficulties in the retrieval of source information. An important issue, therefore, is whether these two brain regions make different contributions to the processing of source information and to the retrieval of episodic memories. / In the present experiments, patients with unilateral excisions restricted to frontal cortex or to the anterior temporal lobe were compared on various tasks examining source memory performance and the accurate retrieval of episodic information. The results of these studies failed to support the general contention that patients with frontal cortex excisions have source (or temporal context) memory impairments. Instead, differences between these patients and normal control subjects appeared to be contingent on whether strategic organizational or control processes were necessary for efficient processing of episodic information. The memory of patients with left temporal lobe excisions, on the other hand, was significantly impaired for both content and source information in most tasks. Furthermore, these subjects showed high rates of inaccuracies and distortions of memory. The false memories of this patient group were attributed to a combination of their poor memory for the specific items of the task and their over-reliance on semantic "gist" or on inferential knowledge about the events. Patients with right temporal lobe excisions were generally less severely impaired on the verbal memory tasks compared with those with left-sided lesions, but were impaired in their memory for the contextual aspects of an event.

Thesis (Ph.D.)--City University of New York, 2003. / Includes bibliographical references (leaves 88-98).

Thesis (Ph. D.)--UCLA, 2009. / Vita. Description based on print version record. Includes bibliographical references (leaves 62-80).

Thesis (M.A.)--York University, 2006. Graduate Programme in Psychology. / Typescript. Includes bibliographical references (leaves 66-75). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR29554