Biomedical subjects

P A Tun

Publications and source records attributed to P A Tun.

7 recordsLinked to original sources

PubMed1995

Age differences in veridical and reconstructive recall of syntactically and randomly segmented speech.

Young and elderly adults listened to spoken passages that were segmented for immediate recall either at natural syntactic boundaries (such as after sentences or major clauses), or at random, nonsyntactic intervals. In addition, speech rate was manipulated using time-compression of the speech materials. Results showed that random segmentation was especially detrimental to the elderly subjects' recall, as was the effect of increasing speech rate. An analysis of subjects' recall errors offered evidence for reconstruction in short-term segment recall in a manner similar to that usually associated with long-term memory.

Adolescent↗

PubMed1992

Rapid speech processing and divided attention: processing rate versus processing resources as an explanation of age effects.

The authors conducted a dual-task study to examine age differences in speech processing under varying loads. Younger and older adults listened to and immediately recalled spoken passages presented at various speech rates (140-280 words per min). This task was performed alone as well as in a divided-attention condition in which subjects concurrently performed a picture recognition task. Consistent with the slowing hypothesis, older adults' immediate memory performance was differentially depressed when speech rates were very fast. The Age x Speech Rate interaction, however, was not exacerbated in the divided-attention condition. This suggests that aging may reduce the rate at which the processing operations underlying memory for speech are completed, but this is conceptually distinct from an age-related reduction in attentional capacity.

Adolescent↗

PubMed1991

Speech-processing capacity in young and older adults: a dual-task study.

Adult age differences in processing speech were examined with a dual-task paradigm. Subjects listened to spoken passages for later recall while performing a concurrent reaction time task intended to index cognitive capacity usage on the speech memory task. Age differences in secondary task decision latencies were eliminated when subgroups of young and older subjects were matched on working memory span. These findings are interpreted as showing that an age-related reduction in working memory efficiency contributes to age differences in processing discourse for memory.

Adolescent↗

PubMed1990

Cognitive and affective disorders in elderly diabetics.

In non-insulin-dependent diabetes mellitus, performance of complex cognitive tasks requiring the storage and retrieval of new information is poorer than in age-matched controls. By contrast, performance of less demanding tasks such as immediate memory and simple reaction time is essentially equivalent for NIDDM patients and controls. This pattern parallels the cognitive change observed with normal aging, in which age differences are minimal on less demanding immediate memory tasks but older adults perform more poorly than young adults on secondary or long-term memory tasks. Age-related changes in cognitive performance have been attributed to a reduction in processing resources or working memory capacity. Although the explanation for NIDDM-related deficits remains to be identified, reduced glucose control and elevated levels of triglycerides appear to play some role in cognitive impairment. Non-insulin-dependent diabetes is associated not only with elevated levels of depression, but with an increased frequency of self-reported memory problems. Moreover, elevated levels of depression are associated with various indicators of neuropathy and with significant reductions in self-regulated control of glucose at the time of medical office visits. Diabetic patients may perceive less control over their lives as a result of the many restrictions associated with the disease. When provided with the opportunity to exercise control, however, performance on many cognitive tasks can be improved in NIDDM as well as in age-matched controls. This suggests that by providing NIDDM patients with opportunities to exercise increased control over their lives it may be possible to enhance motivation and to increase the likelihood of the patient's adopting more effective self-regulatory behaviors.

Aged↗

PubMed1989

Age differences in processing expository and narrative text.

A dual-task procedure was used to examine the effects of text genre on prose processing, comprehension, and recall in 20 young (18-33 years) and 20 old (65-80 years) adults. Response latencies on a secondary task provided an index of cognitive capacity used in reading narrative and expository passages. Both groups recalled more of narratives than of expository passages, although old subjects recalled less than young. Also, the narrative protocols of both age groups showed a greater difference for recall of main ideas as compared to details. Age differences in the pattern of text genre effects were found on measures of comprehension, capacity utilization, and processing efficiency. It appears that the narrative genre facilitated most measures of performance and partially compensated for some limitations in the older group.

Adolescent↗

PubMed1987

Memory self-assessment and performance in aged diabetics and non-diabetics.

Non-insulin dependent diabetes in older adults is associated with elevated depression and a greater decline in certain aspects of cognitive functioning than is found with normal aging. This study sought to determine whether diabetics report more memory complaints in carrying out their daily activities, and if memory self-assessments are reflective of performance on laboratory tasks. Middle-aged (55-64 years) and old (65-74 years) diabetics and non-diabetic control subjects were studied. Results showed that both diabetes and increased age were associated with poorer performance on some cognitive tests as well as with more self-reported memory problems. When depression levels were statistically controlled, the diabetes variable was no longer a significant predictor of memory complaints. The usefulness of self-assessments as an adjunct to more objective cognitive test measures was discussed.

Aged↗

PubMedDate not supplied

Passage difficulty, speech rate, and age differences in memory for spoken text: speech recall and the complexity hypothesis.

Memory for speech in young and elderly adults was studied by varying speech rate and average predictability of prose passages (measured by a "cloze" procedure). Increased speech rate and decreased predictability yielded poorer memory performance on three retention measures (free recall, cued recall, and multiple-choice recognition), confirming passage predictability as a good predictor of empirical difficulty of a speech passage. Older adults recalled less than young adults on all three measures, with increasing speech rates producing special difficulty for the elderly subjects relative to the young. Although there was a suggestion that elderly subjects were less able to take advantage of passage predictability than the young in recall of very rapid speech, neither age group showed an interaction between passage predictability and speech rate. Results are discussed in terms of a simple extension of the complexity hypothesis to speech recall.

Aged↗