Search PubMed⌕ Search

Biomedical subjects

J T Becker

Publications and source records attributed to J T Becker.

At least 109 records · Page 6Linked to original sources
PubMed1987

Cognitive deficits and clinical diagnosis of Alzheimer's disease.

We used cognitive deficits detected by neuropsychological testing to evaluate clinical diagnosis of Alzheimer's disease. Deficits were defined with respect to performance of control subjects according to procedural guidelines set by a NINCDS-ADRDA Work Group. The most frequent deficits were in recent memory and lexical-semantic language abilities. Clinical diagnosis of Alzheimer's disease was compared with diagnosis based on a criterion of two or more cognitive deficits both on initial neuropsychological testing and on testing repeated a year later in some subjects. Initial clinical diagnosis identified 96% of cases who met the criterion when first tested and 100% of those with multiple deficits at follow-up. Specificity with respect to the criterion was 86% on initial testing and 89% at follow-up. These findings support the validity of clinical diagnosis of Alzheimer's disease using the NINCDS-ADRDA criteria.

Aged↗
PubMed1986

Asking the right questions: problem solving in male alcoholics and male alcoholics with Korsakoff's syndrome.

The performance of alcoholics and alcoholics with Korsakoff's syndrome was compared with that of nonalcoholic controls on a task which required the generation of a series of questions for the solution of object and digit/letter identification problems. Each subject attempted to determine which of a set of stimuli (objects, letters, or numbers) the examiner had arbitrarily preselected as correct. The nonalcoholic control subjects asked constraint-seeking questions which reduced alternatives by inquiring about general categories (e.g., "Is it a tool?"). In contrast, the two groups of alcoholic patients assumed the far less efficient strategy of asking hypothesis-scanning and pseudo-constraint questions which provided information only about one of the possible stimuli (e.g., "Is it the saw?"). This similarity in the problem-solving strategies of alcoholics both with and without Korsakoff's syndrome is consistent with the hypothesis that the problem-solving deficits of Korsakoff patients are apparent before the acute onset of their amnesic symptoms. These deficits may be due to alcohol-induced damage to the anterior and posterior cerebral cortical association areas which mediate problem-solving and visuoperceptual functions.

Alcohol Amnestic Disorder↗
PubMed1984

Dissociations between skill learning and verbal recognition in amnesia and dementia.

Patients with Huntington's disease (HD), patients with alcoholic Korsakoff's syndrome, and normal control subjects were compared on tests of skill learning (mirror reading) and verbal recognition. Like previously reported results, the patients with Korsakoff's syndrome acquired the mirror-reading skill at a normal rate but were severely impaired in their recognition of the words used on the mirror-reading task. In contrast to the amnesic patients, the demented patients with HD were retarded in their ability to acquire this skill but showed normal verbal recognition. Besides emphasizing substantial differences in the anterograde substantial differences in the anterograde memory disorders of these two patient populations, the results suggest that the memory disorder of patients with HD may appear much more severe when recall rather than recognition test paradigms are employed. This failure of recall by the patients with HD may be due to an inability to generate strategies necessary to search their short- and long-term memories.

Alcohol Amnestic Disorder↗
PubMed1984

Dexamethasone suppression test in recently detoxified alcoholics: clinical implications.

An overnight dexamethasone suppression test (DST) was performed on 66 nondepressed primary alcoholics, a mean of 20.79 +/- 11.5 days after last alcohol intake. The Beck Depression Inventory (BDI) was given concurrently. Only 6% of the subjects were nonsuppressors. There was no correlation between cortisol levels at 17 and 24 hours postdexamethasone and the age of the subjects or duration of abstinence. There was a low level correlation between cortisol values at 24 hours and the BDI scores. Review of published data indicates that the DST may be abnormal in alcoholics in the first 2 weeks of abstinence, probably a result of abnormal liver function and withdrawal phenomena. DST response of alcoholics resembles that of normal controls after more than 2 weeks of abstinence. Alcoholics with clinical features of depression and an abnormal DST after 2 weeks of abstinence may be candidates for antidepressant therapy or electroconvulsive therapy.

Adult↗
PubMed1984

Impaired memory for treatment-relevant information in inpatient men alcoholics.

Inpatient alcoholics (N = 54 men), nonhospitalized members of an Alcoholics Anonymous group (N = 15 men) and nonalcoholic inpatients (N = 10 men) were shown a 55-min film on alcoholism and were subsequently given memory tests for recall and recognition of information from the film. The performance of the inpatient alcoholics was impaired relative to that of the controls. Alcoholics who were tested earlier in treatment performed worse than those tested 3 or more weeks after their last drink. These results suggest that treatment-relevant information may not be well remembered by alcholics until they have been in treatment for at least 2-3 weeks.

Adult↗
PubMed1984

Oculomotor function in Wernicke-Korsakoff's syndrome: I. Saccadic eye movements.

Saccadic eye movements from three patients diagnosed as having Korsakoff's syndrome and one patient who had suffered the acute Wernicke stage of the disorder were examined for changes in saccadic characteristics. The three Korsakoff patients showed increased saccadic latencies; two of the three also had reduced saccadic peak velocities and increased saccadic durations. A higher than expected incidence of hypometric saccades was also found in all four patients; saccadic intrusions were recorded in two Korsakoff patients. These abnormal oculomotor responses were found 2-7 years after the onset of the Korsakoff's syndrome and are consistent with the cerebellar and frontal lobe dysfunction reported in this patient group.

Alcohol Amnestic Disorder↗
PubMed1984

Oculomotor function in Wernicke-Korsakoff's syndrome: II. Smooth pursuit eye movements.

Smooth pursuit eye movements were studied in three patients with alcoholic Korsakoff's syndrome, one with Wernicke's encephalopathy, and an age-matched control. Horizontal smooth pursuit eye movements were abnormal in all patients: peak eye velocity and the ability to sustain smooth eye velocity were reduced. Also, smooth pursuit gain began to decrease at relatively low target velocities (i.e., 8-10 degrees). These data demonstrate a severe disturbance in smooth pursuit function long after the clinically apparent oculomotor abnormalities have passed.

Aging↗
PubMed1983

A comparison of the effects of long-term alcohol abuse and aging on the performance of verbal and nonverbal divided attention tasks.

The purpose of this study was to assess two versions of the hypothesis that alcohol abuse results in premature aging of the brain and of cognitive functioning. The performances of detoxified long-term alcoholic was compared with that of nonalcoholic controls on three divided attention tasks known to be sensitive to aging. While both forms of the premature aging hypothesis predicted that alcoholics should perform more poorly than controls, the hypotheses differed in their predictions of the interactions between the effects of alcohol and normal aging. The results showed that while all three tasks were sensitive to age, only two were affected by long-term alcohol abuse. On one of the tests affected by both age and alcohol abuse, the performance of both young and old alcoholics was equally impaired whereas on the other, only the older alcoholics had significant difficulties. Based on these findings it was concluded that there was only partial overlap between the effects of alcohol and aging, and that neither of the two forms of the premature aging hypothesis could predict the observed pattern of results.

Aging↗
PubMed1983

Learning to associate names and faces. Impaired acquisition on an ecologically relevant memory task by male alcoholics.

The performance of a group of detoxified male chronic alcoholics was compared with that of age-matched nonalcoholic controls on a memory task which at face value seemed relevant to daily life--i.e., learning to associate people's names with their faces. The alcoholics not only made more errors while learning the face-name associations than did the controls, but fewer of them were able to reach the learning criterion. However, 1 hour later, the alcoholics were nevertheless able to recognize all of the faces and names used during acquisition. The savings scores for the alcoholics, an index of the relative number of face-name associations retained during the 1-hour interval, did not differ significantly from those of the controls. These results demonstrate that the alcoholics' paired-associate learning deficit on this ecologically relevant task is related to their failure to form associations rather than to deficiencies in recognition memory or perceptual processes.

Age Factors↗
PubMed1981

Cognitive mapping in rats: the role of the hippocampal and frontal system in retention and reversal.

These experiments determined the extent to which the hippocampal system and the medial frontal cortex are selectively involved in cognitive mapping in spatial environments. Rats were trained to discriminate between two 3-dimensional objects based on either the location of the objects in the test environment, or on the stimulus characteristics of the objects themselves. Following the acquisition of one of these discrimination tasks, each rat was given a series of transfer tests to determine the extent to which a cognitive mapping strategy had been used to solve the task. Each rat was then given a lesion in the fimbria-fornix or the medial frontal cortex, or a control operation. In the location discrimination, rats with fimbria-fornix lesions, as compared to control rats: (a) performed poorly at the beginning of retention testing; (b) relearned the task to criterion performance; (c) performed normally during the transfer tests indicating that they used a cognitive mapping strategy, and (d) performed poorly in the discrimination reversals. In the object discrimination, these rats performed as well as controls during retention and transfer tests, but had a slight impairment during discrimination reversals. The performance of rats with lesions in the medial frontal cortex was worse than that of the controls during the retention of both discriminations, and during the reversal of the location, but not the object discrimination. These results are related to predictions of current theories implicating the hippocampus and medial frontal cortex in spatially organized behaviors, particularly those behaviors requiring cognitive mapping.

Animals↗
PubMed1980

Neuroanatomical bases of spatial memory.

Although many brain areas have been implicated in spatial memory processes, recent investigations have focused on the hippocampal formation. The present experiment was designed to determine the relative importance of the hippocampal system as compared to the amygdala, the caudate nucleus, or the frontal cortex. Groups of rats were trained to perform on an eight-arm radial maze and then given lesions in one of these brain areas. The post-operative performance of rats with lesions in the fimbria-fornix was never significantly greater than that expected by chance. In contrast, the performance of rats with lesions in the amygdala, the caudate nucleus or the sucal frontal cortex was not significantly different from that of controls. The performance of rats with lesions in the medial frontal cortex was substantially impaired relative to that of the controls during the first few post-operative test sessions, but improved so that by the end of testing the rats were performing as well as were controls. The recovery of function by the rats with lesions in the medial frontal cortex was a function of experience testing on the maze and not simply the passage of time following surgery. Thus, only rats with functional hippocampal systems were able to perform the maze task accurately while thos rats with lesions in the hippocampal system were not.

Amygdala↗
PubMedDate not supplied

Alcohol consumption as a cofactor in the progression of HIV infection and AIDS.

Alcohol consumption as a cofactor in the progression of HIV infection was examined in 1,446 homosexual and bisexual HIV + men enrolled in the Multicenter AIDS Cohort Study who had a minimum of three visits. Two measures of drinking were employed: initial level, and pattern during the study period. Outcome measures included AIDS-related symptoms and AIDS diagnosis. Level of drinking at entry to the study was not significantly associated with either AIDS-related symptoms at final visit or with AIDS diagnosis. However, men who decreased drinking were more likely to report thrush, fatigue, weight loss, and diarrhea at their final visit. Most likely, these men decreased drinking as a result of failing health, not because their drinking pattern influenced symptom onset. These data support earlier reports that found no relationship between alcohol consumption and progression to AIDS.

Acquired Immunodeficiency Syndrome↗