Aspects Of Memory Function Research Articles

Explicit Memory, Procedural Learning and Lexical Priming in Alzheimer's Disease

Different aspects of memory functions were studied in two groups of patients with Alzheimer's disease (AD) and in normal elderly controls. The tests included: explicit memory tests with free and cued recall, and recognition measures; learning of a motor skill; learning of a perceptual skill with verbal material; a priming task with the word stem completion paradigm. The data confirmed that, besides severe impairment for all measures of explicit memory, AD patients were able to learn and retain normally a motor skill in the rotor pursuit task, even across a long retention interval. Moreover, sparing of procedural learning was not restricted to motor tasks, since patients learned normally a mirror-reading task, demonstrating (a) rapid acquisition of the procedure, and (b) acquisition of item-specific information for repeated words. This last effect is accounted for in terms of repetition priming effects rather than of explicit memory strategies, since patients had also normal repetition effect in the word stem completion paradigm.

Memory function in normal aging

We evaluated memory function in a group of 161 community-dwelling, cognitively normal individuals aged 62 to 100 years recruited as part of the Mayo Clinic Alzheimer's Disease Patient Registry. We used the Free and Cued Selective Reminding Test and the Rey Auditory Verbal Learning Test to evaluate two aspects of memory function thought to be sensitive to the effects of aging: learning (acquisition) and delayed recall (forgetting). The results were quite consistent and demonstrated that learning or acquisition performance declines uniformly with increasing age but is not related to education. Delayed recall or forgetting, however, remained relatively stable across age when adjusted for the amount of material initially learned. These findings are relevant for assessing normal memory function relative to the early impairments found in dementia and form a baseline against which memory performance can be assessed by the clinician. In particular, suspicion regarding a disorder of brain function affecting memory processes should be raised if learning performance declines more rapidly than expected or if delayed recall is impaired to any significant extent.

Memory in chronic alcoholics: Effects of inconsistent versus consistent information

Alcoholics and controls were compared on their resistance to misleading information given after a witnessed event. The eyewitness testimony paradigm of Loftus, Miller, and Burns (“Semantic Integration of Verbal Information in a Visual Memory” Journal of Experimental Psychology: Human Learning and Memory, Vol. 4, pp. 19–31, 1978) was used, which is a naturalistic variation of a retroactive interference paradigm. Alcoholics did not show greater suggestibility than the controls, being no more “fooled” by the misleading, after-the-fact information. In contrast, alcoholics did show significant impairment in discriminating correct from among incorrect verbal statements about the accident. Thus, certain aspects of memory functioning may be preserved even while others are compromised as a result of chronic alcohol abuse.

Lexical Acquisition in Alcoholic Korsakoff Psychosis

Recent studies have underlined the importance of the distinction between “declarative” and “procedural” aspects of memory functioning. The purpose of the present study is to evaluate the relative deficits in these two aspects of anterograde memory in an amnesic population with midline diencephalic lesions, to determine whether this apparently fundamental distinction in memory types is honored even under real-world conditions. Eight alcoholic Korsakoff patients were examined for their lexical acquisition capacity, including both their application of word-learning procedures to a new lexical domain and their eventual recall of the facts represented by the new word. The findings revealed that each Korsakoff patient successfully applies at least some of the procedures subserving the word-learning process to the new lexical domain. By comparison, the Korsakoff patients subsequently acquire little of the factual knowledge represented by the new word. Specifically, almost all of the patients recognize only the object used during the exposure period to demonstrate the new word. Quantitative and qualitative features of the patients' declarative and procedural memory deficits are discusses in the context of real-world processing advantages and limitations.

Learner drivers with spina bifida and hydrocephalus: the relationship between perceptual-cognitive deficit and driving performance.

This study investigated the relationship between perceptual-cognitive skills and driving performance in a group of eleven learner drivers disabled by spina bifida and hydrocephalus. Perceptual-cognitive skills assessed include figure-ground discrimination, visual scanning/tracking, spatial orientation, language, reasoning and memory ability. Following ten hours driving tuition in suitably adapted cars, driving performance in off-road manoeuvres and in-traffic situations was measured. Results showed that the perceptual-cognitive skills of this group were in the low average or below average range compared to a non-handicapped population. Spearman Rank Order Correlations between clinical tests and driving performance indicated that although certain tests correlated with off-road manoeuvres, no perceptual measures were reliable indicators of in-traffic driving. There were indications that practical measures of spatial orientation and reasoning ability may be more relevant to some aspects of driving than tested perceptual skills. Memory for road signs, landmarks and routes was also investigated. Accurate retention seemed more dependent on general reasoning ability than tested aspects of memory functioning. It is suggested that as clinically tested perceptual skills do not seem to be reliable indicators of driving performance, an individual's test results should not be used to deter him from learning to drive.

Some aspects of memory functions and the temporal lobes.

Some aspects of memory functions and the temporal lobes.

Association between Low Plasma Tryptophan and Blackouts in Male Alcoholic Patients

Alcohol has been observed to alter various aspects of memory function. Some of the most extreme forms of memory impairment experienced by alcoholics are blackouts. There are at present very few data on the biological mechanisms underlying alcohol-related memory impairment. A variety of mechanisms including the cholinergic and catecholaminergic systems have been implicated in learning and memory. More recently, however, the importance of the serotonergic system in memory function has been demonstrated. We investigated whether patients with a history of blackouts had lower plasma levels of the serotonin precursor tryptophan than patients without such a history. Tryptophan values were significantly lower in patients who had experienced blackouts than in patients who had not. No significant differences between the two group of patients were observed for other amino acids sharing with tryptophan the same transport carrier into the brain. Drinking history variables did not differentiate among the two patient groups. Our data suggest that a decrease in plasma tryptophan (and concomitant lowered brain serotonin) could increase the vulnerability of certain individuals to manifestations of various aspects of memory impairment including one of its most extreme forms, the blackout.

Student Teacher Performance Related to Cognitive Style

Research conducted in the field of cognitive style suggests there are certain learning styles which can be identified, defined and measured. However, the literature points out that a neglected aspect of research is an exploration of relationships between students' cognitive styles and performance. The goal of this study was to explore whether the cognitive style manner of reasoning scales were jointly and differentially, related to student teachers' academic performance. The sample consisted of 40 primary school student teachers enrolled in the second year of the Diploma in Teaching course at the Townsville College of Advanced Education, Townsville, Queensland. Data was gathered by the Hill Cognitive Style Mapping instrument. Student teacher scores on an academic task were used to measure performance. The data were analysed by multiple and stepwise regression techniques. Results of the study were that: (a) cognitive style manner of reasoning scales, operating jointly, contributed 30.~.% of the variance in student teacher academic performance and (b) cognitive style manner of reasoning scales . relationships, categorical and appraisal, operating differentially, accounted for 9.8%, 9.1 % and 8.7% respectively, of the variance in student teacher academic performance. Results were statistically significant at the .05 level. The increasing concern with both the disadvantaged learning student and ing student's learning styles with instruction has stimulated research itive style. Cognitive styles are ways learners process information comes from either outside or inside themselves (Witkin & Moore, Research conducted in the field of cognitive style suggests there are certain which can be identified, defined and measured (Jones & Berneman, . Moreover, Sigel and Coop (1974) posit that cognitive style relates to r\o,-t,·rn,mr·, on academic tasks. If students' preferred learning styles are with instructional tasks effective student learning should be infers th,lt, teachers should draw on a repertoire of strategies match the learning preferences of students with instructional tasks. '-J~ theoretical framework around which cognitive style could be and this study designed, was provided by Joseph Hill of ity College in Michigan, U.S.A. (Hill, n.d.). Hill cognitive style as being composed of four interacting symbols and meaning; cultural determinants of meaning and modalities of inference; and neurological, electrochemical and ~r\'r\'''1 aspects of memory functions. Cognitive style mapping (CSM) is important component of the Hill model. CSM is a diagnostic technique

Cholinergic underactivity in human memory disorders

An age related decrease in central cholinergic neurons that is particularly severe in patients with senile dementia may underlie the cognitive impairment of the aged. This possibility is supported by pharmacological studies demonstrating a decrement in memory processes following administration of anticholinergic drugs and an improvement in some aspects of memory function following the administration of cholinomimetics. The ability of drugs that increase cholinergic activity to improve cognitive processes in the elderly and patients with senile dementia will probably depend on the degree of cholinergic receptor degeneration in these patients.

THE DIFFERENTIAL EFFECTS OF MECLOFENOXATE ON MEMORY LOSS IN THE ELDERLY

A double-blind study of the effects of meclofenoxate on memory performance of fit, able, elderly subjects was carried out. A number of performance measures, designed to measure various aspects of memory function were employed. These revealed that meclofenoxate appears to increase the consolidation of new information into long-term memory, but does not affect other aspects of remembering. It was also found that significantly more of the subjects receiving meclofenoxate reported an increased level of mental alertness.

What is Memory?

Memory is a theoretical construct that may explain current behavior by reference to events that have happened or will happen in the future. Memory may be conceived as a complex, dynamic, recategorising and interactive process based on actual sensory-motor experiences and manifests itself in the behavior of an organism. Repetition in learning is a prerequisite for the formation of accurate and long-lasting memory. Practice is most effective when widely distributed over time, rather than when closely spaced or massed. But even after efficient learning, most memories dissipate with time unless frequently used (Spear, 1978; Spear & Riccio, 1994). Memory always has a subjective and an objective side. The subjective side is observed by the individual’s history (developmental perspective). The objective side is noted by the neural patterns generated by the sensory-motor interactions with the environment. It has been well established by many memory researchers that memory is not a unitary function. This notion is supported by evidence that different brain lesions in patients produce highly specific changes in some aspects of memory functions while sparing other ones. Research has attempted to delineate patterns of impaired and spared memory functions in order to assess whether there is a particular class of processing system that is not functioning while other systems function normally.