Moderation of older adults' retrieval reluctance through task instructions and monetary incentives

Previous research using a noun-pair lookup task indicates that older adults delay strategy shift from visual scanning to memory retrieval despite adequate learning, and that this "retrieval reluctance" is related to subjective choice factors. Age differences in spontaneous response criteria, with older adults valuing accuracy and young adults valuing speed, might account for this phenomenon. The present experiment manipulates instructions and reward contingencies to test the flexibility of response criteria and strategy preferences. Task instructions conditions equally focused on speed and accuracy, encouraged retrieval use as a method toward fast responding, or offered monetary incentives for fast retrieval-based performance. Results indicate that older adults in the incentives condition shifted to retrieval earlier than those without incentives, bolstering the argument that reliance on retrieval is volitional.     

Hand Movement Speed and Accuracy in Detoxified Alcoholics

Detoxified alcoholics (n = 192) were found to be 9.3% slower than age-matched controls (n = 112) with regard to the composite speed (movement time, MT) with which they were able to strike targets of various sizes and distances with a hand-held stylus at onset of a light stimulus (Fitts's Task). Females (n = 102) were 8% slower than males (n = 202), and blacks (n = 103) about 15.6% slower than whites (n = 201). Gender was the only significant factor with regard to errors (target misses), with women committing 28% fewer errors than men. Women, in contrast to men, appear to trade speed for accuracy in this task. Favorable socioeconomic/medical status and target misses were directly related to movement speed. Thus, when the MT data were corrected for lifestyle variables, the significance of the alcohol effects on MT disappeared, but gender differences persisted. The alcohol effect became statistically significant, the ethnic group differences remained statistically significant, and the gender effect became insignificant when MT scores were corrected for accuracy of performance (target misses). The slope of the linear function relating MT to target difficulty was similar for all subgroups. Prior knowledge of the direction of movement was found to affect MT performance more in white than in black subjects. With regard to reaction times, ethnic group and alcohol use effects remained statistically significant after corrections for lifestyle and errors were made, with values for blacks about 5% slower than values for whites, and values for alcoholics about 4.6% slower than those for controls. Prior knowledge of the direction of movement significantly improved (shortened) reaction time in all subgroups (14%-19%).     

The Role of Antisocial, Affective, and Childhood Behavioral Characteristics in Alcoholics' Neuropsychological Performance

Chronic alcoholics demonstrate cognitive deficits when compared with nonalcoholics. These deficits are typically attributed to the direct effects of ethanol and its metabolites on the central nervous system (CNS). There are other factors, however, that differentiate alcoholics from controls, such as personality or behavioral characteristics. These factors may affect neuropsychological performance and thus alter the interpretation of alcoholic cognitive deficits as resulting solely from alcohol's toxic effects. To investigate this question, male and female alcoholics and peer nonalcoholic controls were compared on personality, behavioral, and cognitive measures. Alcoholics had greater numbers of antisocial behaviors, childhood behavioral disorder symptoms (CBD), and affective symptomatology, and had poorer neuropsychological performance than controls. The three personality and behavioral factors were positively intercorrelated with each other, and were negatively related to cognitive performance. The CBD factor proved to be the most consistent predictor of neuropsychological performance for both alcoholics and controls, and males and females. While the behavioral factors differentiated alcoholics from controls and predicted performance, significant differences between the groups in cognitive performance still remained when these factors were taken into account.     

Alcohol and Expectancy: subjective, psychophysiological and behavioral responses to alcohol stimuli in severely, moderately and non-dependent drinkers

Thirty male subjects, 10 severely and 10 moderately alcohol dependent, along with 10 non-dependent controls, were studied in four experimental drinking conditions. Each subject participated in each condition. All subjects received a priming dose of 2 ml 40% vodka/kg or placebo, and a drinking test of 1 ml 40% vodka/kg 45 minutes later. Subjects were told that the priming dose contained ‘alcohol’ in two conditions and ‘soft drinks’ in the two other conditions of the Balanced placebo design. Self-reported desire for a drink and experienced effects from alcohol were more influenced by instructions than by the actual presence of alcohol, although a peak BAG of 0.11% were reached if all available alcohol were consumed (not all subjects did so). Severely dependent subjects demonstrated more craning than the other groups, this difference was observed in the presence of information about alcohol, regardless of whether alcohol was present or not. No differences in speed of drinking were found. The severely dependent subjects showed a higher general arousal than moderately and non-dependent subjects in this experimental setting, as measured by skin conductance level, and they displayed a higher skin conductance response to the instruction that alcohol was to be given. Severely dependent subjects showed a hypothermic response to alcohol. The results confirm our previous findings that expectations of alcohol exerts greater influence on craving than pharmacological effects of alcohol, but the severely dependent subjects are reacting more strongly to alcohol cues than less dependent alcoholics. In addition, the experiment demonstrates that psychophysiological responses are elicited by alcohol cues, and supports a classical conditioning model of alcohol dependence.     

Specific Memory Deficits Associated with Prolonged Alcohol Abuse

The relationship between age, education, length and amount of heavy drinking, and performance on five memory tasks was investigated in 54 chronic alcoholics and 18 age-matched controls. Alcoholics with less than 12 yr of heavy drinking differed reliably from long-term (13–22 yr) and extended long-term drinkers (>23 yr) in recognition memory for visual patterns when scores were corrected for age. Compared with controls, both groups of long-term drinkers were deficient on the visual, auditory, and Faces recognition tests. Age and education of alcoholics accounted for part of performance differences; length of alcohol abuse, however, predicted reliably the decline in memory scores on all but the tactual test. The profile of memory performances seemed to decrease linearly with increasing age and length of alcohol abuse.     

Reliability and validity of the quantitative inventory of alcohol disorders (QIAD) and the veracity of self-report by alcoholics

The purpose of this study was to investigate a recently developed instrument for alcoholism severity: The Quantitative Inventory of Alcohol Disorders (QIAD). The primary intention was to demonstrate the reliability and validity of the QIAD as a diagnostic tool within the field of alcoholism. A secondary intention was to examine the veracity of alcoholics self-report on the QIAD and other alcohol-related instruments. The subjects for the experimental group were 25 inpatient alcoholics and their spouses. The control group consisted of 21 nonalcoholics and their spouses. All subjects were administered the QIAD, Michigan Alcoholism Screening Test (MAST), and the Alcohol Severity Rating Scale (ASRS). The alcoholics and partners were given the same tests 5 to 8 days after initial testing. The primary therapists for the alcoholics were asked to rate alcoholism severity for each subject using the ASRS. Pearson product moment correlation coefficients were used for the test-retest reliability procedure. Alcoholics scores on the QIAD, MAST, and ASRS were compared with their spouses scores using a test-retest procedure. Nonalcoholics scores on these instruments were also compared with their spouses' scores. Construct and concurrent validity for the QIAD were tested through comparison of QIAD scores of the alcoholics with their corresponding scores on the MAST and ASRS. t-Tests were used to determine differences between alcoholics and nonalcoholics on all three scales. The results of this investigation supported the position that the QIAD is a reliable and valid instrument for measuring alcoholism severity. The QIAD correlated highly for both the alcoholics and their spouses. The test-retest procedure revealed a high level of correlation. A significant difference was found between the QIAD scores of the alcoholics and nonalcoholics. Construct validity was demonstrated by significant correlations between the alcoholics QIAD and MAST scores, both measuring the extent of alcoholism. The QIAD demonstrated concurrent validity by significantly correlating with alcoholics ASRS ratings. High correlations between alcoholic and spouse scores on the QIAD supported the hypothesis that inpatient alcoholics can produce valid responses to self-report questionnaires.     

Interpersonal Problem-Solving in Male and Female Alcoholics

This study compared the performance of alcoholics (18 male, 16 female) with community controls (15 male, 12 female) on the Adaptive Skills Battery (ASB), a test of interpersonal problem-solving. The ASB consists of 30 situations. Fifteen situations require subjects' typical responses and 15, their optimal responses. Male and female alcoholics were inferior to controls in their typical responses [F(1,57) = 45.22, p = 0.0001], but did not differ on the optimal responses (F less than 1). Further analyses indicated that decreased feelings of self-efficacy could not account for the alcoholic deficit. Females were superior to males in the optimal response condition [(F(1,56) = 9.90, p = 0.003]. No significant group x sex interactions were obtained. Performance on the ASB was not correlated with performance on traditional measures of problem-solving. Post-hoc correlational analyses revealed differential patterns between depression scores and performance for alcoholics and controls. These data suggest that (1) female and male alcoholics exhibit similar interpersonal problem-solving deficits, (2) alcoholic self-efficacy expectancies cannot account for the impairment, (3) the ASB appears to assess aspects of problem-solving not typically examined, and (4) the role of depression in alcoholic performance deserves continued empirical evaluation.     

Some Aspects of Antioxidant Status in Blood from Alcoholics

The effect of ethanol consumption on serum concentration of alpha-tocopherol, erythrocyte activities of superoxide dismutase, glutathione peroxidase, and catalase were studied in 34 male alcoholics and 35 age-matched controls. Serum concentration of alpha-tocopherol was 30% lower in the alcoholics as compared to the controls (p less than 0.001). No significant difference was found in erythrocyte activities of Cu-Zn-containing superoxide dismutase, glutathione peroxidase, or catalase between the groups. Of the 12 alcoholics with subnormal serum alpha-tocopherol, 50% had concomitant neurological clinical scores and cerebellar atrophy, and their neurological scores were significantly higher (82%) than for alcoholics with normal alpha-tocopherol levels (p less than 0.03). However, no significant correlation was observed between levels of alpha-tocopherol and neurological clinical scores or cerebellar atrophy. When entering the study, alcoholics and controls were each randomized into two separate groups, receiving vitamin E supplementation (100 mg/day) or placebo capsules for 10 days, respectively. In the four subgroups, alpha-tocopherol levels increased only in alcoholics receiving vitamin E supplementation (23%) (p less than 0.001). The reduced serum levels of alpha-tocopherol in alcoholics may be normalized by vitamin E supplementation.     

Motor Performance in Detoxified Alcoholics

Detoxified male and female alcoholics (aged 20-49 years) and age-matched controls performed a series of 15-sec target-tapping tasks in which they alternatively marked two target strips with a felt marker as rapidly and as accurately as possible. Consistent with "Fitts' Law" (Fitts PM: J Exp Psych 47:381-391, 1954), a highly linear relationship between movement time and task difficulty was observed in all four groups. Overall, the alcoholics were slower and made more errors than the controls, although the pattern of deficit differed for males and females. Accuracy, but not speed, was impaired in male alcoholics. The production of undershoot errors was increased more in alcoholics than nonalcoholics in targets of narrower width, whereas the production of overshoot errors was increased more in alcoholics as target separation decreased. Female alcoholics displayed impairment in speed of movement, but not accuracy. However, both alcoholic groups displayed elevated error rates for the more difficult targets. It is thus possible that detoxified alcoholics might mimic the speed functions of nonalcoholic individuals at the occasional cost of an erroneous response at a difficult target.     

Alcohol-related ERP changes recorded from different modalities: a topographic analysis

BACKGROUND: There is controversy in the literature regarding the relationship between event-related-potential (ERP) abnormalities in abstinent alcoholics and stimulus-processing modality (i.e., visual versus auditory). The first purpose of this study was to address questions about whether ERP abnormalities observed in alcoholics are modality specific. The second purpose was to employ current source density (CSD) analyses to investigate topographic differences between alcoholics and controls within each modality. METHODS: Data were collected from 30 sober male alcoholics and 39 normal males in a typical auditory oddball task and in a visual oddball paradigm with novel stimuli, with an extensive set of 61 scalp electrodes. Visual and quantitative assessment of CSD maps as well as analyses of variances on both raw and normalized ERP data were performed. RESULTS: Positive findings were limited to the N1 and P3 components. The visual N1 amplitude was significantly smaller in alcoholics than in controls at the parietal region; no significant group differences in N1 were found in the auditory modality. Alcoholics had widespread reductions in P3 amplitudes in both modalities compared with controls, although in the frontal region this effect was partially due to the influence of age. These P3 reductions in alcoholics were statistically more pronounced in the posterior compared with the anterior regions regardless of modality. Topographically, sources in CSD maps were weaker in alcoholics than in controls; in the frontal and central regions, the weakness was more pronounced in the auditory modality but, in parietal and occipital regions, it was more pronounced in the visual modality. CONCLUSIONS: The results suggest that, in abstinent alcoholics, abnormalities in auditory ERPs may be localized to more anterior sources, while abnormalities in visual ERPs may be localized to more posterior sources. ERP topographic features are more sensitive than amplitude measurements in assessing alcoholic-related modality effects.     

Neurocognitive Deficits in Alcoholics and Social Drinkers: A Continuum?

Our research program has investigated neurocognitive deficits in sober alcoholics for several decades. We have shown that both male and female adult alcoholics – compared with peer nonalcoholic controls – have deficits on tests of learning, memory, abstracting, problem-solving, perceptual analysis and synthesis, speed of information processing, and efficiency. The deficits are equivalent to those found in patients with known brain dysfunction of a mild to moderate nature. Attempts to identify factors other than alcoholism to account for these differences have been unsuccessful. The deficits appear to remit slowly over 4 to 5 years. Relapse of recovering alcoholics is predicted by behavioral (e.g., depressive symptoms and neurocognitive performance) and biological measures (e.g., event-related potentials) obtained at the end of treatment. Results of recent studies support the hypothesis of a continuum of neurocognitive deficits ranging from the severe deficits found in Korsakoff patients to moderate deficits found in alcoholics and moderate to mild deficits in heavy social drinkers (more than 21 drinks/week). Individual differences in the presence and magnitude of neurocognitive deficits in social drinkers and alcoholics are hypothesized to be due, in part, to individual differences in vulnerability of the brain to alcohol or its metabolites' toxic effects.     

Analogical Reasoning Abilities of Recovering Alcoholics

This study investigated analogical reasoning abilities of alcoholics who had been abstinent from alcohol for at least 1 year. Their performance was compared to that of nonalcoholic controls matched as a group for education, age, and gender. Solution times and error rates were modeled using a regression model. Results showed a nonsignificant trend for alcoholics to be faster, but more error prone, than controls. The same componential model applied to both groups, and fit them equally well. Although differences have been found in analogical reasoning ability between controls and alcoholics immediately following detoxification, we find no evidence of differences after extended periods of sobriety.     

Relationships between Neuropsychological Test Performance and Event-Related Potentials in Alcoholic and Nonalcoholic Samples

Are event-related potentials and nonconcurrently measured neuropsychological test performance correlated? Sober male and female middle-aged alcoholics and peer controls were administered an “oddball” event-related potential (ERP) task and several hours later, a battery of neuropsychological (NP) tests. Alcoholics performed significantly poorer than controls on NP tests. Male alcoholics had significantly altered ERP responses (N1, NdA, and P3 amplitudes) but female alcoholics did not differ on any ERP variables from controls. A number of significant correlations between ERP and NP measures were present. The most consistent findings were positive correlations between perceptual-motor (PM) tests and the P3 amplitude at Pz in both male and female alcoholics and in male alcoholics, a negative correlation between PM tests and P3 latency at Pz, findings similar to those seen in Parkinson patients. Significant correlations were most numerous in family history positive alcoholics. The results lead to two conclusions: first, Grant's postulation that sober alcoholics may manifest an intermediate duration organic mental disorder is supported; second, given the lack of ERP differences in the females, ERP measures should not be considered as being causally related to NP performance.     

Neurophysiological Correlates of Response Production and Inhibition in Alcoholics

Scalp recordings of the P300 component of the event-related potential were made from a group of medication-free, chronic male alcoholics and a control group, participating in a visual Go/No Go reaction time paradigm. Subjects were presented with large and small forms of the letters T and V. The large forms (Go stimuli) required a button press with either the left or right hand, whereas the small forms (No Go stimuli) required response inhibition. Recordings were made from 31 electrodes that, for statistical analyses, were grouped into five regions: frontal, central, parietal, occipital, and temporal. The results indicated that, in each of the five regions, both Go and No Go response amplitudes were larger in the controls than in the alcoholics. No group differences in latency were observed in any region. Surface energy (Wang et al., Brain Topogr. 6:193-202, 1994) magnitudes paralleled P300 amplitudes and in the controls, compared with the alcoholics, were larger during both Go and No Go trials. Our findings suggest that abstinent, chronic alcoholics differ electro-physiologically from control individuals. These differences are manifested as widespread reductions in P300 amplitudes during the performance of a simple information processing paradigm. The reduced amplitudes may reflect a deficiency in an inhibitory mechanism proposed to underlie P300 generation.     

Mechanisms of cell death in cholinergic basal forebrain neurons in chronic alcoholics

Tau immunoreactivity was examined in post mortem tissue from patients in three groups: neurologically-asymptomatic and neuropathologically normal alcoholics, alcoholics with Wernicke's Encephalopathy (WE) and age matched non-alcoholic controls. Tau-positive granular and fibrillary inclusions were frequently observed within the magnocellular neurons of the cholinergic nucleus basalis, within occasional nucleus basalis neurons in non-WE alcoholics, but not in controls. Tau immunoreactivity was not however observed in cortical, brainstem, diencephalic or non-cholinergic forebrain structures. Peroxidase activity was also examined within the nucleus basalis using diaminobenzidine as an indicator. The majority of neurons in the basal forebrain showed increased peroxidase activity in all WE alcoholics and in some nucleus basalis neurons of non-WE alcoholics, but was rarely seen in controls. Neighboring astrocytes also showed increased peroxidase activity. These results suggest a link between peroxidase activity and the abnormal accumulation of phosphorylated tau. The presence of tau in the nucleus basalis of alcoholics with WE suggests a thiamine-dependent mechanism in tau accumulation and cell death in the cholinergic basal forebrain.     

Age and Alcoholism: Independent Memory Decrements

Similarities and differences in performances on 18 verbal and nonverbal memory tasks were studied in young and old alcoholics and in young and old controls as test of hypotheses postulating that cognitive decrements from alcoholism either mimic "premature aging," are "age sensitive," or are "independent" from those of normal aging. Young and old alcoholics were matched in length and rate of heavy drinking and were also equated with their controls in age, education, and vocabulary. The multivariate memory and decision data, when converted to independent factor scores, separated alcoholic from control groups on a factor reflecting memory for auditorily presented information. This was independent from factor scores affected mainly by age, such as memory for visuospatial items or decision bias. Age and alcoholism produced overlapping but distinctly different profiles of memory impairments. Decrements in young alcoholics did not resemble those of aging nor did old alcoholics surpass old controls in any but one factor, so that neither the premature aging nor the age sensitivity hypothesis were invariably supported.     

Regional Cerebral Metabolism in Female Alcoholics of Moderate Severity Does Not Differ From That of Controls

It is generally believed that women are more vulnerable to alcohol's toxic effects than men. Studies in male alcoholics have consistently shown reductions in brain glucose metabolism. However, such studies have not been done in female alcoholics. The purpose of this study was to evaluate if similar or worse brain metabolic abnormalities occurred in female alcoholics. For this purpose, we measured regional brain metabolism with positron emission tomography and [¹⁸F]fluorodeoxyglucose in 10 recently detoxified female alcoholics and compared it with that in 12 age-matched female controls. There were no differences between alcoholics and control females in regional brain glucose metabolism whether we used regions of interest analysis or statistical parameter maps methods. These results do not support a higher toxicity for the effects of alcohol in the female brain, as assessed with regional brain glucose metabolism, because metabolic values in female alcoholics did not differ from those of controls, whereas metabolic values in male alcoholics are generally lower than those in controls. However, this study is confounded by the fact that the severity of alcohol use in these female alcoholics was less than that of the male alcoholics previously investigated in positron emission tomography studies. Future studies in male subjects with alcoholism of moderate severity are required to address gender differences in sensitivity to alcohol effects in brain metabolism.     

Speed and efficiency but not accuracy or timing deficits of limb movements in alcoholic men and women

BACKGROUND: Lesions of the cerebellum, a concomitant of alcoholism, can disrupt quality and regularity of movement. Whether evidence for such dysfunction lingers in patients with uncomplicated alcoholism, which is known to affect cerebellar structural integrity, is controversial. METHODS: We used quantitative measures to examine component processes of five classes of movement associated with regional cerebellar function: limb ataxia (alternated finger tapping and variants of the finger-to-nose and heel-to-shin tests), paced tapping, eye-hand coordinated tracing, timed response reflecting preparation and execution time, and postural stability. The subjects examined were 39 abstinent alcoholics (13 men and 26 women) and 21 age-matched controls (9 men and 12 women). For limb ataxia, the dependent measures were the trajectory deviation from the subject's own average movement path and the speed of travel from beginning points to endpoints. RESULTS: Repeated-measures analysis of variance comparing movement speed of finger to nose and heel to shin yielded significant interactions in all conditions (p < 0.007); this indicated that the alcoholics were relatively slower in the upper- than lower-limb tasks. Movements by the alcoholic men were significantly slower but less deviant from an ideal trajectory in all upper-limb conditions than those of the control men (p < 0.002). Although measures of lower-limb movement trajectory did not distinguish the groups, tests of ataxia of stance and gait did. The groups did not differ, however, on tests of timed tapping or sinusoid tracing. CONCLUSIONS: Alcohol-related postural instability in abstinent alcoholics is functional evidence supporting the postulated damage to the anterior superior vermis. Altered speed or accuracy trade-offs, with alcoholics moving slower to attain equivalent or even smaller trajectory deviations, are symptomatic of cerebellar hemisphere dysfunction that is characterized by deliberation of otherwise automatic movements.     

The Manson Evaluation as an Indicator of Heroin Independence*

The Manson Evaluation, designed to identify alcoholics and potential alcoholics, was administered to groups of male and female drug additcs, alcoholics, criminals, and normal subjects. Among the males the mean scores of drug addicts and alcoholics were similar and significantly higher than those of criminals and normal subjects. The mean scores of criminal and normal males did not differ significantly. Mean scores of female drug addicts, alcoholics and criminals did not differ but each was significantly higher than the mean score of normal females. Trait differences among the four groups were also examined.     

Calcium Status and Calcium-Regulating Hormones in Alcoholics

To elucidate effects of chronic ethanol consumption on clinical chemical parameters reflecting overall calcium homeostasis 34 hospitalized male alcoholics and 35 age-matched controls were studied during the winter season. Serum concentrations of 25-hydroxyvitamin D3 and 1,25-dihydroxyvitamin D3 were reduced by 28% (p less than 0.01) and 24% (p less than 0.02) among the alcoholics as compared to the controls, respectively. Dietary intake of vitamin D3 did not differ significantly between the groups. The calcium level was below lower limit of reference in nine alcoholics (26%). Serum concentrations of parathyroid hormone and phosphorus were within normal ranges in both groups, and no differences were observed in levels of magnesium, vitamin D-binding protein, calcitonin, or alkaline phosphatase. In conclusion, it is possible that the activities of enzymes crucial in vitamin D3 metabolism may be altered in alcoholics.