Impaired abstracting ability in chronic alcoholics

Visuoperceptive Impairments in Severe Alcohol Use Disorder: A Critical Review of Behavioral Studies

The present literature review is aimed at offering a comprehensive and critical view of behavioral data collected during the past seventy years concerning visuoperception in severe alcohol use disorders (AUD). To pave the way for a renewal of research and clinical approaches in this very little understood field, this paper (1) provides a critical review of previous behavioral studies exploring visuoperceptive processing in severe AUD, (2) identifies the alcohol-related parameters and demographic factors that influence the deficits, and (3) addresses the limitations of this literature and their implications for current clinical strategies. By doing so, this review highlights the presence of visuoperceptive deficits but also shows how the lack of in-depth studies exploring the visual system in this clinical population results in the current absence of integration of these deficits in the dominant models of vision. Given the predominance of vision in everyday life, we stress the need to better delineate the extent, the specificity, and the actual implications of the deficits for severe AUD.

Neural correlates of visuoperceptive changes in severe alcohol use disorder: A critical review of neuroimaging and electrophysiological findings

Visuoperceptive deficits are frequently reported in severe alcohol use disorder (SAUD) and are considered as pervasive and persistent in time. While this topic of investigation has previously driven researchers' interest, far fewer studies have focused on visuoperception in SAUD since the '90s, leaving open central questions regarding the origin and implications of these deficits. To renew research in the field and provide a solid background to work upon, this paper reviews the neural correlates of visuoperception in SAUD, based on data from neuroimaging and electrophysiological studies. Results reveal structural and functional changes within the visual system but also in the connections between occipital and frontal areas. We highlight the lack of integration of these findings in the dominant models of vision which stress the dynamic nature of the visual system and consider the presence of both bottom-up and top-down cerebral mechanisms. Visuoperceptive changes are also discussed in the framework of long-lasting debates regarding the influence of demographic and alcohol-related factors, together stressing the presence of inter-individual differences. Capitalizing on this review, we provide guidelines to inform future research, and ultimately improve clinical care.

Towards a Dynamic Exploration of Vision, Cognition and Emotion in Alcohol-Use Disorders

Abstract: Visuoperceptive impairments are among the most frequently reported deficits in alcohol-use disorders, but only very few studies have investigated their origin and interactions with other categories of dysfunctions. Besides, these deficits have generally been interpreted in a linear bottom-up perspective, which appears very restrictive with respect to the new models of vision developed in healthy populations. Indeed, new theories highlight the predictive nature of the visual system and demonstrate that it interacts with higher-level cognitive functions to generate top-down predictions. These models nota-bly posit that a fast but coarse visual analysis involving magnocellular pathways helps to compute heuristic guesses regard-ing the identity and affective value of inputs, which are used to facilitate conscious visual recognition. Building on these new proposals, the present review stresses the need to reconsider visual deficits in alcohol-use disorders as they might have cru-cial significance for core features of the pathology, such as attentional bias, loss of inhibitory control and emotion decoding impairments. Centrally, we suggest that individuals with severe alcohol-use disorders could present with magnocellular dam-age and we defend a dynamic explanation of the deficits. Rather than being restricted to high-level processes, deficits could start at early visual stages and then extend and potentially intensify during following steps due to reduced cerebral connec-tivity and dysfunctional cognitive/emotional regions. A new research agenda is specifically provided to test these hypotheses.

Quantitative neurobiological evidence for accelerated brain aging in alcohol dependence

The premature aging hypothesis of alcohol dependence proposes that the neurobiological and behavioural deficits in individuals with alcohol dependence are analogous to those of chronological aging. However, to date no systematic neurobiological evidence for this hypothesis has been provided. To test the hypothesis, 119 alcohol-dependent subjects and 97 age- and gender-matched healthy control subjects underwent structural MRI. Whole-brain grey matter volume maps were computed from structural MRI scans using voxel-based morphometry and parcelled into a comprehensive set of anatomical brain regions. Regional grey matter volume averages served as the basis for cross-regional similarity analyses and a brain age model. We found a striking correspondence between regional patterns of alcohol- and age-related grey matter loss across 110 brain regions. The brain age model revealed that the brain age of age-matched AD subjects was increased by up to 11.7 years. Interestingly, while no brain aging was detected in the youngest AD subjects (20-30 years), we found that alcohol-related brain aging systematically increased in the following age decades controlling for lifetime alcohol consumption and general health status. Together, these results provide strong evidence for an accelerated aging model of AD and indicate an elevated risk of alcohol-related brain aging in elderly individuals.

Alterations in Brain Structure and Functional Connectivity in Alcohol Dependent Patients and Possible Association with Impulsivity

Background

Previous studies have documented that heightened impulsivity likely contributes to the development and maintenance of alcohol use disorders. However, there is still a lack of studies that comprehensively detected the brain changes associated with abnormal impulsivity in alcohol addicts. This study was designed to investigate the alterations in brain structure and functional connectivity associated with abnormal impulsivity in alcohol dependent patients.

Methods

Brain structural and functional magnetic resonance imaging data as well as impulsive behavior data were collected from 20 alcohol dependent patients and 20 age- and sex-matched healthy controls respectively. Voxel-based morphometry was used to investigate the differences of grey matter volume, and tract-based spatial statistics was used to detect abnormal white matter regions between alcohol dependent patients and healthy controls. The alterations in resting-state functional connectivity in alcohol dependent patients were examined using selected brain areas with gray matter deficits as seed regions.

Results

Compared with healthy controls, alcohol dependent patients had significantly reduced gray matter volume in the mesocorticolimbic system including the dorsal posterior cingulate cortex, the dorsal anterior cingulate cortex, the medial prefrontal cortex, the orbitofrontal cortex and the putamen, decreased fractional anisotropy in the regions connecting the damaged grey matter areas driven by higher radial diffusivity value in the same areas and decreased resting-state functional connectivity within the reward network. Moreover, the gray matter volume of the left medial prefrontal cortex exhibited negative correlations with various impulse indices.

Conclusions

These findings suggest that chronic alcohol dependence could cause a complex neural changes linked to abnormal impulsivity.

Poverty Impedes Cognitive Function

The poor often behave in less capable ways, which can further perpetuate poverty. We hypothesize that poverty directly impedes cognitive function and present two studies that test this hypothesis. First, we experimentally induced thoughts about finances and found that this reduces cognitive performance among poor but not in well-off participants. Second, we examined the cognitive function of farmers over the planting cycle. We found that the same farmer shows diminished cognitive performance before harvest, when poor, as compared with after harvest, when rich. This cannot be explained by differences in time available, nutrition, or work effort. Nor can it be explained with stress: Although farmers do show more stress before harvest, that does not account for diminished cognitive performance. Instead, it appears that poverty itself reduces cognitive capacity. We suggest that this is because poverty-related concerns consume mental resources, leaving less for other tasks. These data provide a previously unexamined perspective and help explain a spectrum of behaviors among the poor. We discuss some implications for poverty policy.

The effect of moderate to heavy alcohol consumption on neuropsychological performance as measured by the repeatable battery for the assessment of neuropsychological status

BACKGROUND

Excessive alcohol use is associated with damage to the structure and function of the brain and impairment of cognition and behavior. Traditional test batteries used to assess cognitive performance in alcoholics are extensive and costly, limiting their use across various clinical and research settings. The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) is a relatively new instrument that attempts to overcome some of these limitations. As yet the individual effect of moderate to heavy alcohol consumption on RBANS performance has not been examined. The primary aim of this study was to explore and quantify differences in performance between controls and drinkers on the RBANS and to examine the influence of age, gender, and alcohol use patterns on test performance.

METHODS

Data from a subset of "Using Our Brains" (UoB) donors (n = 28) still actively drinking and meeting criteria for moderate to heavy alcohol use (30 to 80 g of ethanol per day) (Harper, 1988) and 28 matched controls (age, education, and premorbid Intelligence Quotient) were compared.

RESULTS

Participants in the alcohol group performed below the healthy control group on the visuospatial and immediate memory index, and also on the RBANS total score p < 0.001 and showed a greater decline in RBANS scores from estimated cross-sectional premorbid levels. There was a positive association between alcohol ingestion in the preceding 12 months and the language index p < 0.03 and the semantic fluency subtest (p < 0.03). Age was negatively associated with story memory (p < 0.02), coding (p < 0.001), list recognition (p < 0.01), story recall (p < 0.03), and figure recall (p < 0.02).

CONCLUSION

Our results suggest that the RBANS is able to detect and characterize differences in verbal fluency, visuospatial skills, components of declarative memory, and psychomotor speed between healthy controls and moderate to heavy active alcohol users. Executive functions, commonly affected by alcoholism and not included in the RBANS, require assessment with additional measures.

Alcohol: effects on neurobehavioral functions and the brain

Alcoholism results from an interplay between genetic and environmental factors, and is linked to brain defects and associated cognitive, emotional, and behavioral impairments. A confluence of findings from neuroimaging, physiological, neuropathological, and neuropsychological studies of alcoholics indicate that the frontal lobes, limbic system, and cerebellum are particularly vulnerable to damage and dysfunction. An integrative approach employing a variety of neuroscientific technologies is essential for recognizing the interconnectivity of the different functional systems affected by alcoholism. In that way, relevant experimental techniques can be applied to assist in determining the degree to which abstinence and treatment contribute to the reversal of atrophy and dysfunction.

Role of executive functioning in verbal and visual memory

G. Tremont, S. Halpert, D. J. Javorsky, and R. A. Stern (2000) found that individuals with executive dysfunction were more impaired on less structured versus more structured verbal memory tasks. In the present study, the authors investigated the relationship between executive functions and memory in patients with a history of traumatic brain injury by examining the effect of executive functioning on more structured and less structured verbal and visual memory tasks at baseline and 1-year follow-up. Matched subgroups controlled for differences in severity of neuropsychological impairment unrelated to specific executive functions. The G. Tremont et al. (2000) findings were not replicated. Results showed that when acuteness and severity of injury were controlled, executive impairment played no significant role in performance on either more or less structured memory tasks. However, regardless of structure, executive functions played a role in visual memory performance, suggesting that visual memory may be a more fluid ability than verbal memory.

Comparisons of Korsakoff and non-Korsakoff alcoholics on neuropsychological tests of prefrontal brain functioning

BACKGROUND

Evidence suggests that alcoholics exhibit particular deficits in brain systems involving the prefrontal cortex, but few studies have directly compared patients with and without Korsakoff's syndrome on measures of prefrontal integrity.

METHODS

Neuropsychological tasks sensitive to dysfunction of frontal brain systems were administered, along with standard tests of memory, intelligence, and visuospatial abilities, to 50 healthy, abstinent, nonamnesic alcoholics, 6 patients with alcohol-induced persisting amnestic disorder (Korsakoff's syndrome), 6 brain-damaged controls with right hemisphere lesions, and 82 healthy nonalcoholic controls.

RESULTS

Korsakoff patients were impaired on tests of memory, fluency, cognitive flexibility, and perseveration. Non-Korsakoff alcoholics showed some frontal system deficits as well, but these were mild. Cognitive deficits in non-Korsakoff alcoholics were related to age, duration of abstinence (less than 5 years), duration of abuse (more than 20 years), and amount of alcohol intake.

CONCLUSIONS

Abnormalities of frontal system functioning are most apparent in alcoholics with Korsakoff's syndrome. In non-Korsakoff alcoholics, factors contributing to cognitive performance are age, duration of abstinence, duration of alcoholism, and amount of alcohol consumed.

The role of brain oscillations as functional correlates of cognitive systems: a study of frontal inhibitory control in alcoholism

Event-related oscillations play a key role in understanding the brain dynamics and human information processing. In the present study, the Go/No-Go paradigm has been used to examine whether alcoholics have poor inhibitory control as compared to control subjects in terms of different oscillatory brain responses. The matching pursuit algorithm was used to decompose the event-related electroencephalogram into oscillations of different frequencies. It was found that alcoholics (n=58) showed significant reduction in delta (1.0-3.0 Hz) and theta (3.5-7.0 Hz) power during No-Go trials as compared to controls (n=29). This reduction was prominent at the frontal region. The decreased delta and theta power associated with No-Go processing perhaps suggests a deficient inhibitory control and information-processing mechanism. A neuro-cognitive model has been provided to explain the findings. It is suggested that the oscillatory correlates during cognitive processing can be an endophenotypic marker in alcoholism.

Relationship between alcohol consumption and Folstein mini-mental status examination scores among older cognitively impaired adults

The purpose of this study was to determine whether older cognitively impaired adults with significant current or past alcohol histories manifest distinctive cognitive profiles as determined by a widely used cognitive screen, the Folstein Mini-Mental Status Examination (MMSE) test, when compared with older persons without significant alcohol histories. Study participants included 801 consecutive patients, ages 65 years or above, who underwent comprehensive geriatric assessments. Proxy-reported current alcohol intake was classified as none, former, light (<1 drink/week), moderate (> or = 1 but < 14 drinks/week), and heavy (> or = 14 drinks/week), and the presence of an alcohol abuse/dependence disorder was determined by medical record review. Potential exposure-outcome associations were assessed for patients (n = 470) with established cognitive impairment, defined as an MMSE score < 24, and for individuals with MMSE scores > or = 24 (n = 331). Among participants with established cognitive impairment, mean (total) MMSE scores were not significantly different (17.2 vs 16.4 vs 18.5 vs 18.5 vs 17.4) across the categories of current alcohol exposure (none, former, light, moderate, and heavy). Mini-Mental State Examination subscores also did not vary as a function of current alcohol consumption, and a history of alcohol abuse/dependence was not associated with differences in total scores or individual MMSE subscores in this patient group. Among participants with MMSE scores > 24, increased current use of alcohol or a history of alcohol abuse/dependence was not associated with lower total MMSE scores or individual MMSE subscores. Despite these negative findings, prospective investigations of older populations that incorporate more comprehensive cognitive measures are warranted because (1) the Folstein is a brief cognitive screen that does not assess all cognitive domains, and (2) alcohol is a demonstrated risk factor for adverse cognitive outcomes in middle-aged adults and is potentially modifiable.

Ethanol reduces rCFB activation of left dorsolateral prefrontal cortex during a verbal fluency task

In a previous study in normal subjects (Wendt et al., 1994), using a reversing checkerboard as activation stimulus, we found that the coupling between local neuronal activity and regional cerebral blood flow was preserved following ethanol, and that a right-sided occipital activation response seen during sobriety became symmetrical during inebriation. In the present study we investigated if ethanol has a detrimental effect also on the activation of the left dorsolateral prefrontal cortex found in normals during verbal fluency. Measurements of regional cerebral blood flow in 20 healthy, young, male, right-handed volunteers during rest and verbal fluency were made during sobriety and inebriation (0.06% blood alcohol concentration) with a 1-week interval. We found a decrease in word production during inebriation. The normal activation within the frontotemporal part of the left dorsolateral prefrontal cortext was preserved during inebriation. The activation of this region seems thus to be robust to the effects of ethanol. During inebriation no activation response to the word fluency test was found in the anterior prefrontal part of the dorsolateral prefrontal cortex. This region is important for working, temporal, and short-term memory functions, processes that are affected by ethanol. Hemispheric functioning and specialization seem to be adversely affected by ethanol, regardless of which hemisphere is most involved while sober.

Effects of abstinence and relapse upon neuropsychological function and cerebral glucose metabolism in severe chronic alcoholism

Prolonged excessive consumption of alcohol has been associated with a variety of cognitive disorders accompanied by neuropathological and neurochemical abnormalities of the brain, particularly in the frontal lobes. Studies with positron emission tomography (PET) have shown decreased local cerebral metabolic rates for glucose (lCMRglc) in frontal regions, with correlated abnormalities on neuropsychological tests sensitive to executive functioning. This investigation was designed as a pilot study to examine the effects of abstinence and relapse in patients with severe chronic alcoholism studied longitudinally with PET and with neuropsychological evaluation to assess both general and executive functioning. Six patients, including 4 who remained relatively abstinent and 2 who relapsed following their initial evaluation, were studied twice, with inter-evaluation intervals ranging from 10 to 32 months. The patients who remained abstinent or who had minimal alcohol use showed partial recovery of lCMRglc in two of three divisions of the frontal lobes and improvement on neuropsychological tests of general cognitive and executive functioning, whereas the patients who relapsed had further declines in these areas. These results, although based upon a relatively small number of subjects, provide preliminary support for at least partial recovery of metabolic and cognitive functioning in individual patients who abstain from alcohol.

Educational lectures and films in the clinical treatment of alcoholism: a critique

A recent meta-analysis of alcohol treatment outcome research concluded that educational lectures and films are an ineffective treatment modality in the treatment of persons with alcohol-related problems. This paper suggests several reasons why educational lectures and films are likely to be ineffective with alcohol misusers. Possible explanations include (a) the inability of alcoholics to appreciate and utilize (presented) information because of the cognitive deficits associated with chronic alcohol misuse, (b) the presentation of inaccurate or misleading information about alcoholism through lectures and films (i.e., unitary disease concept, faulty conceptualizations of denial), and (c) conventional alcoholism education which may undermine an individual's belief in her/his ability to make a complete and successful recovery from chemical dependence. Treatment implications and suggestions for further research are briefly discussed.

Metabolic mapping of the effects of chronic voluntary ethanol consumption in rats

The 2-[14C]deoxyglucose method was used to examine the effects of chronic, voluntary ethanol consumption on rates of local cerebral glucose utilization (LCGU). LCGU was measured in male Long-Evans rats immediately following the completion of a 60-min schedule-induced polydipsia drinking session. Three groups of animals were examined: animals with a history of ethanol consumption that received ethanol on the test day (ethanol-ethanol), animals with a similar ethanol history that were presented with water on the test day (ethanol-water), and a control group that received water throughout the experiment (water-water). Ethanol consumption on the test day resulted in a highly discrete pattern of metabolic changes, with significant decreases in glucose utilization in the hippocampal complex, habenula, anterior ventral thalamus, and mammillary bodies, whereas increases were observed in the nucleus accumbens and locus coeruleus. Rates of LCGU in the ethanol-water group were increased throughout all regions of the central nervous system examined, indicating that the long-term consumption of moderate ethanol doses that do not produce physical dependence can cause significant changes in functional brain activity.

Anterior brain dysfunctioning as a risk factor in alcoholic behaviors

This study assessed the relationship between neuropsychological and electrophysiological functioning and four alcohol-related measures: the Michigan Alcoholism Screening Test (MAST), the age at which the first drink was taken, frequency of drinking to "get high", and frequency of drinking to "get drunk". Ninety-one young adult men with no history of alcohol dependence were recruited. Subjects completed a variety of alcohol-related scales and a battery of neuropsychological tests. Resting EEG activity was also recorded. Stepwise regression analysis found that neuropsychological tests commonly regarded as measuring frontal and/or temporal neocortex functioning predicted the age at which subjects took their first drink and their scores on the MAST. Tests of frontal functioning, along with tests of memory, also predicted the frequency with which subjects reported drinking to "get drunk". Tests of memory also predicted the frequency at which subjects drank to "get high". On two of the alcohol measures, including age at which the first drink was taken and frequency of drinking to "get high", left-frontal slow alpha EEG activity was a significant predictor. These results suggest that markers of anterior brain functioning/dysfunctioning are associated with self-reports of alcohol-related behaviors, and that disturbances in the integrity of the anterior neocortex may be a risk factor in the development of alcohol-related behaviors.

The alcohol paradox: a psychological model

The paradoxical continuation of excessive drinking by chronic alcoholics despite extremely aversive personal deterioration is addressed by a two-factor theory. The theory regards the increasing stereotypy of alcohol-related behaviors as a function of: (a) primary neuropsychological impairments that result from alcohol abuse and (b) secondary fears of catastrophic failure attendant upon brain dysfunction, which leads to acquired aversions to situations that require adaptive behaviors. A schematic quantitative model of this formulation is presented that may be useful to practicing psychologists in explaining perserverative behavior in a variety of brain syndromes.

Alcoholic dementia

At least four distinct cerebral diseases--Wernicke-Korsakoff, Marchiafava-Bignami, pellagrous encephalopathy, and acquired hepatocerebral degeneration--have a close association with chronic alcoholism. Each is characterized by a distinctive pathologic change and a reasonably well-established pathogenesis; in each the role of alcohol in the causation is secondary. The question posed in this review is whether there is, in addition to the established types of dementia associated with alcoholism, a persistent dementia attributable to the direct toxic effects of alcohol on the brain--i.e., a primary alcoholic dementia. The clinical, psychologic, radiologic, and pathologic evidence bearing on this question is critically reviewed. None of the evidence permits the clear delineation of such an entity. The most serious flaw in the argument for a primary alcoholic dementia is that it lacks a distinctive, well-defined pathology, and it must remain ambiguous until such time as its morphologic basis is established.

Effects of a history of heavy alcohol consumption on Alzheimer's disease

Neuropsychological and psychiatric evaluations were made of 39 subjects with possible Alzheimer's disease and a history of excessive alcohol consumption (AD + ETOH), who had been abstinent or had drunk minimally for at least three months before evaluation, and 225 patients with probable Alzheimer's disease (PAD) of comparable age, years of education, and baseline global impairment. At baseline, there were no significant differences between the groups in terms of age of onset of dementia, neuropsychological test scores, or current behavioural or psychiatric symptoms. One year later, no differences in rates of decline between 20 abstinent AD + ETOH patients and 88 PAD subjects could be shown. Thus, past heavy alcohol consumption does not appear to modify the presentation of dementia of the Alzheimer's type, nor does it modify progression over a one-year interval.

Effects of insulin-dependent diabetes on learning and memory efficiency in adults

Previous work with elderly adults with maturity-onset non-insulin-dependent diabetes has demonstrated the presence of significant learning and memory deficits which are correlated with the degree of chronic hyperglycemia. This study was conducted to examine learning and memory processes in a group of 82 younger adults (mean age = 33.4 years) with a long history (mean duration = 26.2 years) of childhood-onset insulin-dependent diabetes. Contrary to expectation, diabetic subjects performed as well as a group of 82 age- and SES-matched nondiabetic control subjects on all measures of learning and memory. On the other hand, they performed significantly worse on measures of psychomotor efficiency, with degree of chronic hyperglycemia being the best predictor of psychomotor slowing. These findings, together with earlier studies of elderly diabetic patients, suggest that specific neural systems within the aging brain may be differentially sensitive to the "toxic" effects of chronic hyperglycemia.

Event-related potential evidence of dysfunction in automatic processing in abstinent alcoholics

The preattentive automatic processing of 63 alcoholics and 27 controls was evaluated with an auditory inattentive event-related oddball paradigm. We examined the mismatch negativity and the N2-P3 complex. Results showed significantly greater amplitude for N2, P3 and the N2-P3 complex for controls but no individual lead (Fz, Cz, Pz) differences by group. A group-by-lead interaction was found for N2 and for the N2-P3 complex. There were no significant latency differences between groups; however, a significant age-by-group interaction effect on latency was greatest at the Cz electrode. Results reflect a possible aberration of automatic processing in alcoholics because of a defect in the mnemonic template necessary to match with an infrequent deviant stimuli. We also found suggestive evidence of a relative weakness of frontal cortical organization in alcoholics. Future studies are suggested that would help clarify these differences in alcoholics.

Self-regulation of slow cortical potentials in psychiatric patients: alcohol dependency

Ten unmediated alcohol-dependent male inpatients participated in a Slow Cortical Potential (SCP) self-regulation task utilizing biofeedback and instrumental conditioning. These patients were hospitalized for treatment of alcohol dependency after chronic abuse of alcoholic beverages. Somatic withdrawal symptomatology had occurred recently and the patients were free of any withdrawal symptoms of the autonomic nervous system. Immediately after hospitalization patients were unable to control their SCPs without the reinforcement of immediate feedback across 4 sessions. Seven patients participated in a fifth session an average of 4 months later. Six out of these 7 patients had not had a relapse at the follow-up. In the fifth session these patients were immediately able to differentiate between the required negativity and negativity suppression, whereas the seventh patient, who had relapsed, was unable to control his brain potentials successfully. Results are further evidence that some of the frontocortical dysfunctions in alcohol-dependent patients are reversible. This could covary with a morphological restitution of the cortex.

Standardized and flexible batteries in neuropsychology: an assessment update

This article summarizes current literature relevant to commonly used tests and test batteries in clinical neuropsychology. The first section contains a discussion of the philosophy and relative advantages of standardized and flexible battery approaches in neuropsychology. The second contains historical background and a literature review of the two major standardized test batteries: the Halstead-Reitan and Luria-Nebraska. The third section includes reviews of tests that are frequently used in the flexible battery approach. Various tests of intellectual functioning, attention, memory, language, and spatial analyses are critiqued in this section. Contributions of the process approach are noted. The article ends by underscoring the need for continued research into the nature of neuropsychological measures and the abilities they assess.

Effects of chronic alcoholism on hemispheric functioning: an examination of gender differences for cognitive and dichotic listening tasks

A pattern of intact verbal abilities and impaired visuospatial abilities has led to a hypothesis of alcohol-induced right-hemisphere dysfunction in male chronic alcoholics. The applicability of this hypothesis to chronic female alcoholics was examined by administering the WAIS-R, Stark Paired Associates Tasks, and dichotic listening tasks to 15 male and 10 female alcoholics and 15 male and 10 female controls of similar age and education. Alcoholics had significantly lower Full Scale IQ scores on the WAIS-R but neither sex had a Verbal-Performance IQ difference indicative of right-hemisphere dysfunction. Male alcoholics showed deficits on both the Verbal and Visuospatial Stark Tasks, the deficit being greater on the Visuospatial Task. Male alcoholics showed an increased right-ear superiority on the verbal dichotic listening task and a decreased left-ear superiority on the musical dichotic listening task, both indicative of right-hemisphere dysfunction. The results, except for the WAIS-R, support the hypothesis that male but not female chronic alcoholics exhibit right-hemisphere dysfunction. Females, alcoholic or not, appear to be less lateralized in function.

Experience-dependent neuropsychological recovery and the treatment of chronic alcoholism

This paper reviews the relationship between cognitive status and treatment outcome in chronic alcoholics, the natural history of recovery, and the role of cognitively oriented remediation programs in facilitating recovery. Seven studies of experience-dependent recovery are described in which behavioral improvement was noted. Various recommendations for treatment over the course of recovery are made, guided by anticipated changes in capacity to process complex information over time.

Retention of orienting reaction habituation in chronic alcoholics

A polygraphic study on resistance to habituation of the somatic (EMG), autonomic (finger plethysmogram, galvanic skin reaction, respiration) and EEG (acoustic-evoked potential and EEG-blocking reaction) components of the orienting reaction, elicited by a repetitive auditory stimulus during successive (weekly) sessions was performed in 67 chronic alcoholics and in 70 matched normal subjects (control group). The study showed significant retention disturbances of orienting reaction habituation (i.e., of learning), or the "saving" of stimulations, achieved from one session to the other to obtain the habituation criterion, the savings being less in alcoholics than in control subjects. The severity of habituation retention disturbances depended on patients' ages, types of alcoholism, alcohol consumption intensity and chronicity, as well as the type of resting EEG.

Effect of social drinking on neuropsychological performance

The effects of social drinking on neuropsychological function have been assessed in a group of healthy male volunteers. Subjects were divided into three groups according to their daily alcohol consumption: (1) 40 g or less (n = 93), (2) 41-80 g (n = 22), (3) 81-130 g (n = 16). Group 1 had been drinking at the present level for a mean of 12.6 years, group 2 for 16.9 years and group 3 for 15.1 years; the differences are not significant. There are no significant differences on any neuropsychological tests variables between groups 1 and 2. However, subjects in group 3 were found to perform at a significantly lower level than groups 1 and 2 on the Rey Auditory Verbal Learning Test, the Austin Maze, and the Little Man and Spatial Memory Tests of the Bexley Maudsley Automated Psychological Screening Test. The pattern of deficits found in heavy social drinkers is less severe but otherwise similar to that found in alcoholics.

Cognitive functioning of alcoholics and its relationship with prognosis

In a preliminary study a group of 30 alcoholics were subjected to psychological tests to explore the influence of regular alcohol intake on their cognitive functioning and its relationship with prognosis. The functions chosen were, arousal and maintenance of attention, verbal intelligence and performance intelligence. Tests used were the Binet Kamat test of intelligence and Bhatia short scale. Level of education was positively correlated with attention-span and verbal intelligence, but not with performance intelligence. The inter-test discrepancy alone on the performance intelligence test could be assessed for evaluation of cognitive impairment. Poor P.Q. scorers sought medical consultation before their mid thirties and had earlier onset of alcoholism. Elder addicts (above 35 years) showed more abstraction deficiency. The higher the P.Q. the higher was its' positive correlation with adjustment to work, but not to family.

Astrocyte proliferation precedes a decrease in basket cells in the dentate fascia following chronic ethanol treatment in mice

The effect of chronic ethanol administration on the density of basket cells in the dentate gyrus of mice selectively bred for their sensitivity to acute ethanol exposure (long-sleep, LS and short-sleep, SS) was assessed in two experiments. In addition, the effect of chronic ethanol on the density of dentate granule cells and astrocytes was examined. In the first experiment, mice received 3 weeks of a liquid ethanol diet with 35% of their calories derived from ethanol (EDC). In this experiment, LS mice did not demonstrate a change in the density of granule cells or in the density of basket cells. There was, however, a significant increase in the density of astrocytes as a result of this treatment for the LS mice. The SS mice were unaffected on all measures. In the second experiment, portions of which have been reported previously, mice received a diet with 23% EDC for 3 months. As a result of this exposure, LS mice showed a significant decrease in the density of basket cells, but there was no change in the density of granule cells or astrocytes. There was no difference between controls and experimental mice from the SS group on any of these parameters. These results suggest that at least in the dentate gyrus, chronic ethanol treatment selectively reduces the density of basket cells but only in mice that are more sensitive to the hypnotic effects of acute ethanol exposure. Furthermore, this effect seems to be preceded by an apparent increase in the density of astrocytes.(ABSTRACT TRUNCATED AT 250 WORDS)

Accelerated mental aging in alcoholic patients

Discriminant function and polynomial regression methods were used to define a mental age function from scale score profile patterns found in the WAIS manual. Values on the mental age function then were calculated from WAIS scale score profiles for 164 alcoholics in the age range 35 to 74. Validity of the mental age function was evident in clear discrimination between chronological age groups in the alcoholic sample. As compared with WAIS normative values for the mental age function, the mean mental age for patients in the alcoholic sample was advanced approximately 7 years over age-matched normals. Unweighted means ANOVA revealed the accelerated mental aging of alcoholic patients to be statistically significant. This finding is discussed in the context of other research that supports a premature aging hypothesis.

Learning in young alcoholics

A group of young male alcoholics with a mean age of 26.7 years performed less well than matched controls on a test of complex maze learning. The relatively short period of time during which these alcoholics had been drinking to excess (M = 5.7 years) suggests that acquired deficits may appear earlier in the drinking history of many alcoholics than has been previously assumed. Data from the maze was analyzed by modelling each individuals' cumulative error scores with a two-parameter hyperbolic function. The model provided an excellent fit to individual data and group differences were observed in both parameters of the model. It is concluded that curve fitting provides an efficient method for representing individual performance on a multitrial learning task.

Brain impairment in social drinkers? No cause for concern

Correlations between measures of alcohol consumption and cognitive test scores have been interpreted to reflect a chronic toxic effect of ethanol on brain function in light to moderate social drinkers. However, the data indicate that there is little support across research groups for any specific relationship and, at best, the effect of alcohol consumption accounts for only a small proportion of variance. Consideration of test validity suggests that the principal measure of ability used in this research is not capable of elucidating cerebral deficit. Further, the pattern of observed correlations is not consistent with the assumption that the putative effects of social drinking involve deficits less severe but similar in type to those seen in chronic alcoholics. Instead, an association between innate ability, demographic variables, and drinking behavior in the general population is the most parsimonious explanation of all the data.

Cognitive dysfunction and aging among male alcoholics and social drinkers

The relationship between aging and various drinking styles was examined. Four age groups (25-34, 35-44, 45-54, and 55-65 years) and four drinking styles (nondrinkers, social drinkers, alcoholics, and abstinent alcoholics) were compared. A battery of eight neuropsychological tests was administered to 322 men; 72 nondrinkers, 100 social drinkers, 58 abstinent alcoholics, and 92 alcoholics. Cognitive dysfunction related to aging was found to be a more significant factor than decline with alcohol use. Cognitive dysfunction associated with alcohol use was significant for three Wechsler Adult Intelligence Scale subtests; Vocabulary, Digit Symbol and Block Design. Alcohol-related differences in intellectual functioning tended to diminish with increasing subject age.

Normalization of regional cerebral blood flow in alcoholics during the first 7 weeks of abstinence

Twenty-two institutionalized alcoholics were studied after 1, 3, 5 and 7 weeks of abstinence with measurements of the regional cerebral blood flow (rCBF), psychometric testing and clinical ratings. Twenty-two healthy volunteers served as age-matched controls. Mean rCBF was significantly reduced in the alcoholics at all measurements compared to the controls. The older alcoholics (median cut) showed a 9% increase of rCBF from the 1st to the 7th week (P less than 0.01). The mean rCBF in these alcoholics also increased more in the right than in the left hemisphere (P less than 0.05) during the investigation. The differences between the alcoholics and the controls were most pronounced in the right frontal lobe. The mean flow changes were correlated to improvement in clinical state. Right hemisphere and frontal lobe flow decreases were more accentuated in older alcoholics.

Cognitive deficits related to memory impairments in alcoholism

Cognitive impairments related to alcoholism are examined in terms of input, intervening, and output variables. Respectively, the dysfunctions are represented by visuospatial/perceptual abnormalities, affective/conative deficits, and strong perseverative response tendencies. Defects in one or more of these aspects of cognitive functioning may appear as problems of memory. Functional differences between subgroups of alcoholics who do and do not develop severe anterograde amnesia characteristic of Korsakoff's syndrome presumably are attributable to differences in the distribution and extent of brain pathology. Both subgroups have widespread cortical pathology, which may play an important role in stimulus-processing deficiencies observed in both. Korsakoff's have demonstrated a more significant degree of pathology in diencephalic and basal forebrain structures than that observed in non-Korsakoff alcoholics; this may contribute to the greater memory and affective impairments in the former. However, in no subgroup of alcoholics can a single functional system or brain region be implicated as the major contributory factor. Rather, damage to multiple brain regions likely is responsible for the plethora of cognitive difficulties reported in the alcoholism literature.

Specificity of memory deficits in alcoholism

Inferences of specific impairments in memory from prolonged abuse of alcohol have come from initial studies reporting that visuospatial memory and problem solving were impaired but verbal memory and learning were not. The apparent specificity, however, is demonstrated to be an artifact of the more difficult visual tests. With task complexity increased, impairments are shown also in both learning and recall of words, story, or designs. A common condition for deficits to be detected is the demand for effort in encoding and retrieving of to-be-remembered information. In general, deficits are mild and diffuse and do not seem to be clearly specific to material or modality. Furthermore, deficits are more pronounced in old alcoholics, although these tend to have longer drinking careers. Age and length of abstinence are more significant predictors of impairment than length or rate of alcohol drinking; however, concomitant disease and familial history of alcoholism are recognized to contribute to wide differences in effort-requiring memory processing.