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Biomedical subjects

C Flicker

Publications and source records attributed to C Flicker.

10 recordsLinked to original sources
PubMed1992

Hypersensitivity to scopolamine in the elderly.

Scopolamine hydrobromide, 0.43 mg/70 kg, was administered by subcutaneous injection to ten young and ten elderly subjects. A comprehensive neuropsychological test battery was used to assess the effects of scopolamine, as compared to placebo, on cognitive function. As previously reported for this group of young subjects, scopolamine significantly impaired performance on tests of recent memory and visuospatial praxis. The same effects were observed in the elderly subjects, but the magnitude of the effects was much larger. The scopolamine injections produced significant psychomotor slowing in the elderly, whereas higher doses of the drug are required to produce this effect in young subjects. In both young and old subjects scopolamine failed to affect immediate memory, language function, object sorting, and the frequency of intrusion errors (although trends toward an effect were more apparent in the elderly). Remote memory, tested in the elderly only, was also unaffected. The results suggest that scopolamine's cognitive effects are quantitatively more pronounced in elderly subjects than young subjects, but that they are qualitatively similar and do not constitute a valid model for the cognitive dysfunction associated with Alzheimer's disease.

Adolescent↗
PubMed1991

Mild cognitive impairment in the elderly: predictors of dementia.

We conducted full diagnostic evaluations, including a comprehensive cognitive assessment battery, of a group of 32 elderly subjects with a clinically identified mild cognitive impairment and a group of 32 age-matched and education-matched normal subjects. The mildly impaired subjects performed significantly more poorly than the controls on tests of recent memory, remote memory, language function, concept formation, and visuospatial praxis. Follow-up evaluations of cognitive status 2 years later revealed clinically detectable cognitive decline relative baseline in 23 (72%) of the mildly impaired subjects. Several of the objective psychological tests accurately discriminated at baseline between the decliners and nondecliners in the mildly impaired group. Among the 20 mildly impaired subjects with no complicating conditions, 16 exhibited cognitive deterioration between baseline and follow-up. These results suggest that most elderly subjects with mild cognitive deficits, as determined by clinical evaluation and objective psychological testing, will manifest the progressive mental deterioration characteristic of dementia and that psychometric predictors can be used to distinguish between benign and more significant underlying disorders in mildly impaired elderly subjects.

Aged↗
PubMed1990

Scopolamine effects on memory, language, visuospatial praxis and psychomotor speed.

Scopolamine hydrobromide was administered by subcutaneous injection to 30 young subjects in a dose of 0.22 mg/70 kg, 0.43 mg/70 kg, or 0.65 mg/70 kg. Treatment effects were compared to placebo on an extensive cognitive assessment battery. Almost all tests in the battery had been previously administered to Alzheimer's disease patients and nondemented elderly subjects. Scopolamine produced deficits on tests of verbal recall, visuospatial recall, visual recognition memory, visuospatial praxis, visuoperceptual function, and psychomotor speed. Immediate memory, language function, object sorting, and frequency of intrusion errors were unaffected. The low dose of scopolamine produced some peripheral anticholinergic signs but did not affect the cognitive measures. The results support the conclusion reached in previous studies that the cognitive profile of scopolamine-injected young subjects is more similar to that of the nondemented elderly than to that of Alzheimer's disease patients.

Adolescent↗
PubMed1990

Impaired facial recognition memory in aging and dementia.

Young normals, aged normals, and patients with early and advanced probable dementia of the Alzheimer type (DAT) were administered a facial recognition memory task. A continuous recognition paradigm was used, in which subjects were instructed to identify the repeated faces in an ongoing series of faces presented on a video monitor screen. A signal detection analysis of the data revealed that the DAT patients were markedly impaired in their ability to discriminate between new and repeated faces. Multiple presentations of faces improved the recognition accuracy of the early DAT patients only, but their rate of learning was slower than that of the normal subjects. In comparison to the young normals, elderly normals exhibited a mild deficit in recognition memory. All of the elderly subject groups exhibited a more liberal response bias than the young normals, which eliminates the possibility that the impaired memory task performance of the aged subjects could be attributed to a more conservative test-taking strategy. The DAT patients exhibited impaired recognition even when the second presentation of a face immediately followed the first, which perhaps implies that task performance was also sensitive to the effect of DAT on visuoperceptual abilities or psychomotor speed.

Adolescent↗
PubMed1988

Equivalent spatial-rotation deficits in normal aging and Alzheimer's disease.

Two tests of spatial-rotation ability were administered to 17 young normals, 23 aged normals, and 51 patients with diagnoses of Alzheimer's disease (AD). The AD patients consisted of 28 early dementia patients and 23 advanced dementia patients. On a computerized version of the Boston Naming Test, 40 objects were presented for naming, 20 of which were rotated 180 degrees. The subjects' capacity for mental rotation was assessed on the basis of their accuracy of naming of rotated vs. unrotated objects. On Money's Standardized Road Map Test, in which the subject is asked whether turns on a map are to the left or to the right, spatial-rotation ability was assessed on the basis of the subject's left-right orientation on turns with movement away from the subject (requiring no rotation) vs. turns with movement toward the subject (requiring rotation). Performance on both tasks was progressively worse in the young normal, aged normal, early dementia, and advanced dementia groups. Both tasks demonstrated a clear spatial-rotation deficit in the elderly. Although the spatial-rotation effect was superimposed upon deficits in naming and left-right orientation in the demented subjects, the magnitude of the rotation effect did not significantly differ in the aged normal vs. the early dementia group on either task, suggesting that early AD produces no further impairment of spatial-rotation abilities than is produced by normal aging.

Adolescent↗
PubMedDate not supplied

Age differences in the vulnerability of facial recognition memory to proactive interference.

A facial recognition memory task was administered to 16 young subjects (age range 18-30) and 28 elderly subjects (age range 63-83). A continuous recognition paradigm was used, in which subjects were instructed to identify the repeated faces in an ongoing series of faces presented on a video monitor screen. A signal detection analysis of the data revealed a mild recognition memory deficit in the elderly, due mainly to an increase in false positives during the second half of the test session. This age-specific increase in late-session false alarms may be a result of increased sensitivity of the aged subjects to proactive interference from previously presented faces. Increasing the length of the delay between the initial and repeat presentation of a face decreased recognition accuracy in both groups, but the young subjects were more sensitive to the delay interval effect than the elderly. Multiple presentations of faces produced a comparable improvement in the recognition accuracy of both young and old subjects. The elderly subjects exhibited a more liberal response bias than the young subjects, indicating that impaired memory task performance of the aged subjects cannot be attributed to a more conservative test-taking strategy.

Adolescent↗