PubMed Health⌕ Search

Biomedical subjects

L Prescott

Publications and source records attributed to L Prescott.

24 records · Page 2Linked to original sources
PubMedDate not supplied

Performance but not acquisition of skill learning is severely impaired in the elderly.

A battery of cognitive tests, specifically designed to assess verbal and skill learning, was administered to healthy volunteer subjects of different ages. Although there were age-related declines in initial and terminal performance in both a pursuit rotor and a mirror reading task, the increase in performance with practice on these tasks was little affected by age. Recall, but not recognition, of verbal material was also impaired in the elderly, as were some measures of frequency estimation. These findings are compatible with the contention that, although acquisition of declarative tasks, which requires conscious processing, is impaired in the elderly, acquisition of nondeclarative tasks, which can be learned without conscious awareness, is not affected by age. However, classical conditioning may be an exception to this generalization for reasons that are at the present time unknown.

Journal Article↗
PubMedDate not supplied

Leg flexion conditioning in the rat: its advantages and disadvantages as a model system of age-related changes in associative learning.

Twelve- and 28-month-old Fischer 344 rats of both sexes received five 60-trial sessions of Pavlovian conditioning in which the CS was a 75 dB, 10,000 Hz tone, and the US was a 0.5-mA, 0.5-sec duration footshock. Right foreleg flexion was measured as the conditioned response (CR). Other animals received a random sequence of unpaired tones and footshock and served as pseudoconditioning control groups. Interstimulus intervals (ISIs) of 1.5 and 3.5 sec were studied. The longer ISI resulted in higher rates of responding in both the conditioning and pseudoconditioning groups. However, with the exception of the young males, all animals showed significantly higher levels of responding in the conditioning groups. Females also showed faster acquisition and higher levels of responding than males. A significant sex by age by sessions interaction occurred, suggesting that old males may be somewhat retarded in acquiring the leg flexion CR compared to the other groups of animals. Old males were also slower to reach a criterion of 5 successive CRs than either young males or young or old females.

Aging↗
PubMedDate not supplied

Attitudes towards aging and physical health.

Brief narrative descriptions of four hypothetical individuals who differed in age and physical health were developed and presented to people who differed in age and sex. Each participant read only one of the four profiles. After reading the profile, the participant rated the profiled individual on the Rosencrantz and McNevin (1969) semantic differential scale of attitudes towards aging. Respondents were divided into a young group (29 years or younger), a middle-aged group (30-49 years), and an old group (50 years and older). No participant gender effects were found. All three age groups rated the older and younger profiles of persons in poor health more negatively than those describing healthy persons on each of the three dimensions of the Rosencrantz-McNeven scale. Older respondents tended to view the younger healthy profile and to a lessor extent the younger-sick profile more positively than the older profiles, but the young and middle-aged respondents viewed the older profiles more positively than the younger profiles on all three dimensions of the scale. These findings suggest that (a) a major component of negative attitudes toward the aged may be related to the more likely occurrence of physical illness in this age group, and (b) more negative attitudes toward the aged are more likely to occur in older than younger respondents regardless of health status.

Adolescent↗
PubMedDate not supplied

Some determinants of attrition in prospective studies on aging.

Demographic measures, psychosocial variables, and objective and subjective measures of physical impairment were assessed in elderly men twice at intervals of 12 to 18 months. Canonical discriminant function analysis of the relationship between these predictor variables on the first testing and whether participants (a) returned for retesting, (b) did not return because of apparent disinterest, or (c) did not return because of illness or death, revealed two significant canonical variates. The first, characterized by decreased mental and physical capacity, discriminated between the deceased/ill group and the other two groups. The second was characterized by decreased social interaction and life satisfaction, and increased life events, and distinguished between the disinterested group and the other two groups. However, both groups that failed to return for retesting showed evidence of impaired physical health and a general disengagement from social and personal activities, compared to the retested group.

Adaptation, Psychological↗