PubMed Health⌕ Search

Biomedical subjects

B P Cooper

Publications and source records attributed to B P Cooper.

7 recordsLinked to original sources
PubMed1997

Automatic category search and its transfer: aging, type of search, and level of learning.

We examined the site of learning as a function of task type and age. Two experiments examined whether learning in semantic category search is exclusive to trained elements of categories or generalizable to other elements of the trained categories. Specifically, we examined how practice searching for small subsets of exemplars from taxonomic categories transferred to untrained elements of those categories. Young and old adults received extensive practice on memory search (Experiment 1) or visual search (Experiment 2) tasks. Participants then transferred to conditions assessing whether learning was exclusive to the trained words or generalizable to other elements of the trained categories. The site of learning in memory search appears to be at the category level for both young and old adults. Level of learning in visual search appears to differ as a function of age. Young adults' learning generalizes to the category level, whereas older adults' learning is specific to the trained words.

Adolescent↗
PubMed1996

Aging and individual differences in the development of skilled memory search performance.

We examined individual differences in measures of multiple intellectual abilities and performance on a pure memory search task over 5 experimental sessions. Old (n = 104) and young (n = 97) participants showed expected patterns of substantial improvement in memory search intercepts and slopes in consistently mapped (CM) conditions, relative to varied mapping (VM) conditions. Initial (unskilled) CM and VM memory search was highly correlated with a Semantic Memory Access Speed factor and moderately correlated with General Intelligence. Structural equation models showed that measures of Semantic Memory Access remained a strong predictor of skilled CM search performance in both age groups despite individual differences in CM memory search performance changes. These results indicate qualitative differences in the nature of automaticity between memory search and visual search and suggest age invariance in the mechanisms determining automaticity in memory search.

Adolescent↗
PubMed1995

Understanding performance and learning in consistent memory search: an age-related perspective.

This study was conducted to investigate learning in memory search tasks. Young and old participants were trained for 5,640 trials of consistent mapping (CM) and varied mapping (VM) memory search. After training, participants were transferred into New CM and CM Reversal conditions. During training, both young and old adults improved reaction time performance, with more rapid improvement for the young adults. In CM training, both age groups achieved zero comparison slopes, indicating automaticity in CM memory search. VM training maintained a large age-related difference in search times. Age did not moderate the transfer effects, suggesting similar learning mechanisms were responsible for the original CM training gains in both age groups; however, transfer effects were different for CM Reversal and New CM. The pattern of transfer data argues against several possible mechanisms for automaticity in memory search. The data are most compatible with a hypothesis of memory-set unitization as the locus of automaticity in memory search.

Adolescent↗
PubMed1995

Age-related retention of skilled memory search: examination of associative learning, interference, and task-specific skills.

Young and older adults performed skilled memory search after either a 3- or 6-month retention interval. Participants were first trained in consistent-mapping (CM) memory search; then, one of the search conditions was subjected to interfering processing activity prior to the retention interval. Retention testing simultaneously examined situations where interfering processing activity either did or did not intervene between original learning and retention testing. In addition, general task-specific learning was assessed. Results indicate that (a) old and young adults equally retained general, task-specific skills; (b) old adults' performance declined more than young adults' performance for trained CM stimuli; (c) when an interfering processing activity was inserted prior to the retention interval, old adults' performance declined disproportionately more than young adults' performance, especially when compared to the task not subjected to such interference; and (d) for both old and young adults all initial retention deficits were quickly eliminated within retention retraining.

Adolescent↗
PubMed1975

Periodic alternating nystagmus.

A typical case of periodic alternating nystagmus is described. Periodic alternating nystagmus is a form of horizontal or horizontal-rotary jerk nystagmus of which the most characteristic feature is an alternation in direction at regular intervals. The condition appears to be not as rare as has been believed previously and may indicate a lesion in the upper part of the medulla.

Adult↗
PubMedDate not supplied

Improved synthesis and rapid isolation millimole quantities of adenylysulfate.

An improved enzymatic method for the synthesis of adenylysulfate (APS) from adenosine 5'-phosphate using APS-reductase from Thiobacillus denitrificans is described. Isolation of millimole quantitities of this sulfur nucleotide is achieved rapidly by means of ion exchange chromatography on a strongly basic ion exchange resin. A facile and reproducible desalting procedure is described.

Adenosine Monophosphate↗