ABSTRACT
BACKGROUND: The delayed alternation (DA) task is highly sensitive to the deficits of nonhuman animals with alcohol-related brain damage. DA is thought to measure working memory which serves as a temporary store for processing of information. However, performance on this type of task has only been investigated in alcohol-dependent humans with severe cognitive deficits. The aim of the current study was to explore the validity of DA as a test sensitive to alcohol-related brain damage by manipulating storage and processing components in three versions of the task. It was hypothesized that alcohol-dependent people would perform worse than control participants and that their deficits would be more pronounced in DA versions with maximal working memory demands. METHODS: A sample of 12 alcohol-dependent participants without Wernicke-Korsakoff syndrome was compared with a sample of 12 nonalcohol-dependent controls on three versions of DA. These versions, in order of increasing working memory demand, were single alternation (LR), double alternation (LLRR), and asymmetric alternation (LRRR). DA was administered on a personal computer and performance measured by the number of trials taken to reach criterion. RESULTS: Alcohol-dependent participants, compared with the control participants, took more trials to reach learning criterion on DA on all versions when analyzed together (p = 0.002). Performance on DA was also found to deteriorate with increased working memory demands in both groups of participants (p < 0.001). However, the deficits of alcohol-dependent participants were most pronounced on the DA task with moderate (LLRR) as opposed to extreme (LRRR) working memory demands. CONCLUSIONS: The results indicate that both storage and processing demands are necessary for task performance and demonstrate sensitivity of DA to alcohol-related brain injury.
Subject(s)
Alcoholism/complications , Memory Disorders/etiology , Adult , Alcoholism/physiopathology , Brain Diseases/etiology , Humans , Learning , Middle Aged , Prefrontal Cortex/physiopathologyABSTRACT
This article represents the proceedings of a symposium at the 2000 RSA Meeting in Denver, Colorado. The organisers/chairs were Stephen C. Bowden and Fulton T. Crews. The presentations were (1) Age, genetic and other factors that increase risk of alcoholism also increase alcohol-induced neurotoxicity, by Fulton T. Crews; (2) A neurocognitive moderation model of addictions treatment response, by Marsha E. Bates; (3) The relationship of neurocognitive impairment and longitudinal treatment outcome among substance-abusing patients, by William Fals-Stewart; and (4) Treatment of cognition in detoxifying alcohol-dependent participants, by Margaret L. Ambrose.
Subject(s)
Alcoholism/complications , Cognition Disorders/chemically induced , Nervous System Diseases/chemically induced , Substance-Related Disorders/complications , Alcoholism/physiopathology , Alcoholism/therapy , Animals , Brain/physiopathology , Cognition Disorders/therapy , Humans , Nervous System Diseases/therapy , Substance-Related Disorders/therapy , Thiamine/therapeutic useABSTRACT
BACKGROUND: Wernicke-Korsakoff syndrome (WKS) is most often seen in people who are alcohol dependent. Treatment with thiamin may rapidly resolve acute symptoms. However, much evidence suggests that identification of WKS on clinical examination is relatively insensitive when compared with diagnosis at postmortem. No study has investigated the therapeutic effect of thiamin in a sample of alcohol-dependent people without the clinical triad of acute WKS. METHODS: We conducted a randomized, double-blind, multidose study of thiamin treatment in 107 subjects who were detoxifying from alcohol. Five groups of subjects were assessed with the Mini-Mental State Examination and were examined for the presence of neurological signs. Subjects were given different doses of intramuscular thiamin for two consecutive days. The posttreatment performance of these groups then was examined on a test of working memory derived from comparative neuropsychology, namely, the delayed alternation task. This test has been established as sensitive to the neuropathology of WKS. RESULTS: Pretreatment measures of mental status and neurological signs were equivalent across groups. Groups were equated with respect to the background variables of age, education, typical daily alcohol consumption, and years of drinking. On the posttreatment measure, a superior performance was found in the group that received the highest dose of thiamin, compared with the other four treatment groups. CONCLUSIONS: A therapeutic relationship between dose and working memory performance was indicated. These results have important implications for the management and prevention of WKS, but further investigations are needed to substantiate the nature of the therapeutic relationship.
Subject(s)
Alcoholism/drug therapy , Korsakoff Syndrome/prevention & control , Mental Status Schedule , Thiamine Deficiency/drug therapy , Thiamine/therapeutic use , Adult , Alcoholism/complications , Analysis of Variance , Ataxia/drug therapy , Double-Blind Method , Humans , Memory/drug effects , Memory/physiology , Middle Aged , Thiamine/pharmacology , Thiamine Deficiency/complicationsABSTRACT
This study explored the relationship between 3 dimensions of organizational structure--centralization, formalization, and size--and perceptions of procedural and interactional fairness. Data from 11 organizations (N = 209) indicated that, as predicted, centralization was negatively related to perceptions of procedural fairness, and organizational size was negatively related to interactional fairness. However, contrary to predictions, formalization was not related to perceptions of procedural fairness. Results suggest that organizational structure and design should play a more prominent role in our thinking about organizational fairness.