Biomedical subjects

William J Hoyer

Publications and source records attributed to William J Hoyer.

8 recordsLinked to original sources

PubMed2007

Aging, focus switching, and task switching in a continuous calculation task: evidence toward a new working memory control process.

This study examined switching of the focus of attention in working memory in relation to global task switching in a continuous calculation task using two rules (midpoint and up-and-down) in a group of 25 younger adults and a group of 23 older adults. Age differences emerged in accuracy when participants worked on two strings simultaneously (necessitating a focus switch); focus switching did not interact with age in the response time domain. No age differences were obtained for global task switching. Ex-Gaussian decomposition showed a shift due to focus switching in all parameters, but a shift in leading edge only for task switching. The results suggest that task switching and focus switching rely on different processes, and that there is a specific age-related deficit in focus switching.

Adolescent↗

PubMed2006

Aging selectively impairs recollection in recognition memory for pictures: evidence from modeling and receiver operating characteristic curves.

Young and older adults were tested on recognition memory for pictures. The Yonelinas high threshold (YHT) model, a formal implementation of 2-process theory, fit the response distribution data of both young and older adults significantly better than a normal unequal variance signal-detection model. Consistent with this finding, nonlinear z-transformed receiver operating characteristic curves were obtained for both groups. Estimates of recollection from the YHT model were significantly higher for young than for older adults. This deficit was not a consequence of a general decline in memory; older adults showed comparable overall accuracy and in fact a nonsignificant increase in their familiarity scores. Implications of these results for theories of recognition memory and the mnemonic deficit associated with aging are discussed.

Adult↗

PubMed2006

The associative-memory basis of cognitive skill learning: adult age differences.

It has been established that memorizing common problems and their solutions underlies cognitive skill development, and that there are substantial age deficits in the rate of this learning. In a between-groups design, the authors compared learning rates for the same set of problems in skill (SK) training and paired-associate (PA) training. The authors found main effects due to condition (PA problems were acquired earlier) and to age (older adults' learning was delayed), but no condition-by-age interaction. The authors concluded that the age deficit in SK can be accounted for by the age deficit in associative memory; no further explanation is needed. The authors also analyzed fast and slow retrieves in SK and PA, and found that the frequency of fast retrieves did not differ in the two conditions. The overall advantage of PA was due to the occurrence of slow retrieves, which were absent in SK presumably because the skill algorithm displaces slow, explicit memory search in SK, but not fast, familiarity-based retrieval.

Adolescent↗

PubMed2006

Determinants of retrieval solutions during cognitive skill training: source confusions.

Diverse outcomes, both facilitative and disruptive, have been reported for the effect of interpolated item recognition tests on the acquisition of a cognitive skill. We collected data from a repeated set of 12 artificial arithmetic problems, soliciting compute/retrieve strategy reports after every trial. In one condition, a recognition test was administered after every three blocks of training. Recognition testing was found to depress retrieve frequencies in both younger and older adults, particularly for newly acquired items. Pairing training items with similar recognition foils mitigated these effects. This pattern of results could be explained by assuming that the participants based compute/retrieve decisions on item familiarity or frequency, tracked across both skill trials and recognition trials, and on a threshold influenced by source confusion. Variations in the threshold parameter could lead to depressed reports of item retrieval (our findings) or to elevated retrieval decisions, as has been shown in some other studies.

Adolescent↗

PubMed2004

Adult age and digit symbol substitution performance: a meta-analysis.

This article reports the results of a meta-analysis of the effects of age, education, and estimated year of measurement on scores from the Wechsler Adult Intelligence Scale and the Wechsler Adult Intelligence Scale-Revised Digit Symbol Substitution Test. Analysis of effect sizes for age reported in 141 studies published between 1986 and 2002 indicated a mean standardized difference of -2.07. Age accounted for 86% of the variance in a regression model using age, education, and year submitted as predictors of Digit Symbol scores. There was no association between years of education or year submitted and Digit Symbol scores for younger adults or older adults.

Adult↗

PubMed2004

Cognitive skill learning: age-related differences in strategy shifts and speed of component operations.

Younger and older adults solved novel arithmetic problems and reported the strategies used for obtaining solutions. Age deficits were demonstrated in the latencies for computing and retrieving solutions and in the shift from computation to retrieval. Rates of improvement within age groups were parallel for computations and retrievals, suggesting a single, age-attenuated mechanism that affects practice-related speedup. The age-related delay in strategy shift suggests either reluctance to use retrieval or an associative memory deficit. Experiment 1 showed that skill acquisition was unaffected by the presence and frequency of postresponse strategy probes for both age groups. Experiment 2 showed that pretraining item-learning operations facilitated subsequent item learning and that pretraining either item-learning operations or the algorithm did not alter the age trends.

Adult↗

PubMed2003

Age, skill, and contextual cuing in target detection.

This study examined the extent to which structural regularities inherent in visual arrays help to guide target detection and reduce age-related differences in skilled visual search performance. The target-detection performance of medical laboratory technologists in 2 age groups (M = 24.3 years and M = 49.0 years) and age-matched novices was assessed using images of bacterial morphology taken from Gram's stain photomicrographs as targets and search arrays. For skilled observers, response times were longer for middle-aged adults than for young adults except when external location cues were available, or when contextual cues inherent in the array were available to guide target detection. These results demonstrate that contextual information aids the skilled search of middle-aged experts, and suggest that contextual cuing is 1 means by which middle-aged adults can circumvent the effects of normally age-deficient processes on performance in a skilled domain.

Adult↗

PubMed2003

Item learning in cognitive skill training: effects of item difficulty.

Item difficulty effects in skill learning were examined by giving participants extensive training with repeated alphabet arithmetic problems that varied in addend size (e.g., C-D = ? is easy; C-J = ? is harder). Recognition memory for the items, as measured by interpolated recognition tests, was acquired early in training and was unaffected by item difficulty. Memory for the solutions to items, as measured by the participants' strategy reports that they had retrieved, rather than computed, the solution, was acquired later and was affected by item difficulty. Solutions to easier items were learned earlier in training for both young adults (18-24 years) and older adults (60-75 years), superimposed on an overall lower level of solution learning in older participants. The results suggest that the formation of associations between problems and their solutions is effortful and shares limited processing resources with the computational demands of the problem.

Adolescent↗