The purpose of this thesis was to investigate short-term memory disorder in elderly, psychiatric patients and to attempt to relate this disorder to the concept of "neural excitability". There is no doubt that some elderly, psychiatric patients suffer from a short-term memory deficit. Many investigators have reported that patients with diagnoses of senile psychosis or psychosis with cerebral arteriosclerosis experience serious difficulty with "initial learning" or the immediate recall of new, or at least freshly presented, stimuli. A number of studies have suggested that this short-term memory disorder may be the result of a disruption in one of the mechanisms which has been proposed to account for the ability of young, adult subjects to respond sequentially to stimuli presented simultaneously through different sensory channels. One of these mechanisms has been termed the "p system", which only passes information successively; the other, the "s system", which can contain simultaneously information from two channels. This latter mechanism is the short-term store which is required for the effective handling of simultaneously presented, dichotic stimuli, and which is apparently the defective mechanism in elderly, psychiatric patients with memory disorder. A binaural, simultaneous stimulation experiment was conducted. Two groups of 20 elderly, psychiatric patients (one with clinically ascertained memory disorder and the other without such disorder) were tested using tape-recorded digits. Within these two main groups the conditions of recall were manipulated for the purpose of examining what effect the prescription of the order of recall would have upon the ability of the patients to recall the binaural digits. Half of the subjects from each main group were told before the presentation of the digits which channel they would be required to reproduce first, and the other half was told after the presentation. The general experimental hypotheses were that, under the "before" condition, the memory-disordered subjects would have significantly greater difficulty recalling the stored digits (second channel recalled) than would the non-memory-disordered subjects; this difference would be magnified in the "after" condition. Although the results from some portions of this experiment were not fully in accord with expectation, they all were in the predicted direction. Several possibilities were advanced in an attempt to account for this failure to achieve statistical significance, and for some of the disparities between present results and those from previous studies conducted along similar lines. However, the experimental findings did lend weight to the idea that in some elderly, psychiatric patients there is a breakdown in the short-term storage system of the type proposed by previous investigators. The underlying cause for the short-term memory deficit of some elderly, psychiatric patients may be a reduction in the neural excitability involved in the short-term storage process. A current neuropsychological model proposes a two-stage process of memory functioning: reverberatory activity and permanent changes in the nervous system as a result of this activity. A second experiment was conducted using a cumulative learning paradigm with the aim of examining the efficiency of these stages in elderly, psychiatric patients. Essentially the same two groups of subjects were again tested with a list of repeated and non-repeated series of digits. The hypothesis here was that, in contrast to the control subjects, the experimental subjects would not display cumulative learning of the repeated series of digits. In supporting the experimental hypothesis, the results also indirectly reinforced the notion that elderly, memory-disordered patients suffer from a reduction in the energy of the electrical oscillations and/or an impedance of the neural network, both of which would mitigate against any structural modification based on reverberations. Although the experimental subjects in these studies all displayed a severe short-term memory dysfunction, it was suspected that they were not totally incapable of learning, provided they were given sufficient opportunity for practice. The third and final experiment in this thesis dealt with the serial learning of words which were to be recalled or recognized by the same subjects involved in the first two studies. It was expected that the memory-disordered patients would be inferior to the non-memory-disordered on both a recall and recognition task, but that both groups would show evidence of learning over a series of trials, the control group displaying the greatest amount of improvement under both conditions. The experimental results suggest that at least some learning does occur even where the patients exhibit gross memory disorder but that there is a definite limit to the amount of material which can be learned by these patients. Taken together, the results of these three experiments lend support to the notion that the memory disorder manifested by some elderly, psychiatric patients may be referable to a reduction in cerebral reverberatory activity which makes longer-term learning virtually impossible. / Arts, Faculty of / Psychology, Department of / Graduate

In an attempt to characterize the nature of semantic memory impairment in persons with dementia of the Alzheimer type (DAT), a free association task, a definition task, and an associate rank ordering task were administered to 10 mildly and 13 moderately impaired DAT subjects, and 14 normal control subjects. The DAT subjects presented a free association response profile that was markedly different from normal controls. Further, DAT subjects provided meaningful definitions to many of the words used as stimuli in the free association task. Relative to controls, DAT subjects demonstrated a deterioration in their ability to rank order words according to the strength of their association to a stimulus noun. The presently obtained data suggest that the semantic memory impairment in DAT can be characterized, in part, as a deterioration in the associative structure between concepts and a loss of conceptual knowledge.

The purpose of this investigation was to determine the test-retest response consistency rate on a semantic memory task in persons with dementia of the Alzheimer type (DAT). Ten mildly and 13 moderately impaired DAT subjects and 14 normal controls matched for age, years of education, and estimated IQ participated in this study. The Peabody Picture Vocabulary Test (PPVT) was administered twice to each subject with a seven day inter-test interval. The mild and moderate DAT subjects responded inconsistently to significantly more PPVT items than normal controls. When the effects of guessing were considered, moderate DAT subjects gave significantly more inconsistent PPVT responses than normal controls and mild DAT subjects showed a trend towards giving more inconsistent responses. These results substantiate the conclusion that the impairment of specific conceptual knowledge in DAT subjects cannot be reliably measured with a single administration of a semantic memory task such as the PPVT.

The purpose of the present study was to investigate the efficacy of a memory and metamemory training program on memory performance and metamemory judgement accuracy in adults with a closed head injury. A multiple baseline across subjects design was used with six subjects. All subjects were seen at least two years post-injury. Training included general metamemory information about the nature of memory, use of a specific memory strategy to assist verbal recall (to Preview, Question, Read, State and Test- PQRST), specific metamemory information about the strategy, and a self instruction procedure (WTSC- What is the task, Select a strategy to use, Try out strategy, Check to evaluate strategy effectiveness). During the training period all subjects recalled greater than fifty percent of paragraph ideas while using PQRST. Follow-up tests showed that five of the six subjects maintained recall levels but a gradual decrease in slope was observed over eight weeks post-training. Tests of recall, recognition and metamemory judgements on Sentence and Action Tasks were used to evaluate generalisation of training. Two subjects showed improved recall and two subjects showed improved recognition performance. In addition, four subjects demonstrated greater metamemory judgement accuracy about recognition performance following training. Improved performance post-training was also observed for three subjects on the Rivermead Behavioral Memory Test and the Logical Memory subtest of the Wechsler Memory Scale-Revised, greater than that expected for repeated testing. Several factors were identified as having a role in subjects’ ability to benefit from training.

Thesis (Ph. D.)--University of Oregon, 2003. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 124-128). Also available for download via the World Wide Web; free to University of Oregon users.

Adherence to antipsychotic medication in schizophrenia has been shown to predict symptom exacerbations; however, adherence remains poor in this population. The concept of taking medication on a maintenance regime is an example of prospective memory (PM). The current investigation is comprised of three studies in which 59 outpatients diagnosed with schizophrenia completed a comprehensive assessment including measures of PM, executive functioning, comprehension of medication instructions, insight into the need for medication, and environmental variables supporting adherence. An objective measure of medication adherence was also collected during a one-month baseline period. In study 1, medication adherence was conceptualized as a PM task and variables for predicting adherence based on PM literature were examined. Of the hypothesized variables, the interactive effect of PM ability and comprehension of medication instructions was the only predictor of adherence to antipsychotic medication. Comprehension of medication instructions alone was the only predictor of adherence to total psychotropic medication regime. Study 2 investigated the role of executive functions in the awareness of PM deficits and use of compensatory strategies. Results indicated that patients with poorer executive skills were less reliable in their report of PM ability compared to performance on PM measures. However, both fair and poor executive functioning groups reported similar use of compensatory strategies. Lastly, the third study manipulated the specificity of retrieval context for a 5-day habitual PM task intended to mimic medication-taking. The aim of this investigation was to examine the effect of retrieval context specificity and executive functioning on task performance. Results demonstrated that patients categorized as fair executive functioning completed significantly more days of the habitual task than patients categorized as poor executive functioning. There was no difference in performance between patients receiving greater retrieval context specificity versus patients receiving a general context. However, there was a trend for individuals with fair executive functioning to benefit from greater retrieval context specificity, implying that a minimum level of executive skill may be necessary for individuals to recognize the risk of a restricted retrieval interval and/or mobilize additional resources for encoding. Clinical implications are discussed. / text

An impression which has dominated both the clinical setting and research literature is that patients with temporal lobe epilepsy (TLE) not infrequently issue "bitter" complaints about their memory function. This observation has rarely been subjected to investigation, based as it is, on the implicit assumption that TLE subjects are "entitled" to a memory disturbance given the involvement of a critical memory structure (i.e, hippocampus) in the pathogenesis of the disorder. While it is almost axiomatic that clinicians become aware of memory difficulties because of the subjective complaints issued by patients, there is growing awareness that the relationship between complaint and objective memory disturbance is a complex and often counterintuitive one. This is particularly true of many patients with TLE who while complaining about their memory function often do so in the presence of objectively normal interictal memory function. / This thesis addressed the question: Why do patients with TLE complain about their memory? It was premised on the notion that memory self-report is not a unidimensional construct explicable in terms of an underlying memory dysfunction alone, but the perception and expression of memory may arise from seemingly disparate sources. The principal objective of the thesis was to systematically and comprehensively investigate the complaint in TLE, and to derive an understanding of the variables which contribute to the perception and expression of poor memory in members of this population. The variables selected for investigation emerged from a detailed review of the literature and can be grouped into five broad conceptual domains: demographic, epileptological, psychological, cognitive, and metacognitive. (For complete abstract open document)

Thesis (M.Psych.(Clinical)/Ph.D.)--University of Western Australia, 2006.

Thesis (Ph. D.)--University of California, San Diego and San Diego State University, 2005. / Vita. Includes bibliographical references (leaves 62-73).

Thesis (Ph. D.)--University of Queensland, 2003. / Copy missing chapter 1. Includes bibliographical references.