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J M Duchek

Publications and source records attributed to J M Duchek.

15 recordsLinked to original sources
PubMed1999

Cross-modal semantic and homograph priming in healthy young, healthy old, and in Alzheimer's disease individuals.

Two experiments are reported that explore the influence of strength of the prime-target relationship on the observed priming effects in young, healthy old, and individuals diagnosed with dementia of the Alzheimer type (DAT). In Experiment 1, participants were auditorily presented primes (FURNITURE) and after varying delays presented visual targets that were (1) high-strength related (e.g., SOFA), (2) low-strength related (e.g., RUG), or (3) unrelated control words (e.g., COW or DEER). The results indicated that the DAT individuals produced relatively larger priming effects that both the young and the healthy old, but these data could be accommodated by increases in effect size due to general slowing of response latencies. In Experiment 2, the same cross-modal priming paradigm was used with ambiguous words presented as primes (e.g., BANK) and either high-dominant (e.g., MONEY) or low-dominant (e.g., RIVER) words as targets. The results of Experiment 2 produced a qualitatively distinct pattern of priming that indicated DAT individuals only produced priming for high-dominant targets and not for low-dominant targets, whereas, the healthy control groups produced equivalent priming for both high- and low-dominant targets. The discussion focuses on the implication that these results have for the interpretation of semantic priming effects, in general, along with implications for the apparent semantic memory loss in DAT individuals.

Adolescent↗
PubMed1998

Attention and driving performance in Alzheimer's disease.

The present study examined the relationship between visual attention measures and driving performance in healthy older adults and individuals with very mild and mild dementia of the Alzheimer type (DAT). Subjects were administered an on-road driving assessment and three visual attention tasks (visual search, visual monitoring, and useful field of view). The results indicated that error rate and reaction time during visual search were the best predictors of driving performance. Furthermore, visual search performance was predictive of driving performance above and beyond simple dementia severity and several traditional psychometric tests. The results suggest that general cognitive status may be useful for identifying individuals "at risk" for unsafe driving. However, measures of selective attention may serve to better differentiate safe versus unsafe drivers, especially in the DAT population.

Aged↗
PubMed1997

Reliability of the Washington University Road Test. A performance-based assessment for drivers with dementia of the Alzheimer type.

OBJECTIVE: To assess the reliability and stability of a standardized road test for healthy aging people and those with dementia of the Alzheimer type (DAT). DESIGN: A prospective study involving patients with DAT and age-matched healthy controls in which subjects' driving performance was evaluated by several raters in an initial and a follow-up road test. SETTING: Urban medical school and urban highways and streets. SUBJECTS: A convenience sample of 58 controls, 36 subjects with very mild DAT, and 29 subjects with mild DAT. RESULTS: Analysis of road test ability of controls (2 subjects [3%] failed the test), very mild DAT subjects (7 subjects [19%] failed), and mild DAT subjects (12 subjects [41%] failed) disclosed a significant association between driving performance and dementia status (chi 2[4] = 20.65 [N = 123]; P < .001; Kendall tau-b = 0.306). Interrater reliability for assessment of driving performance ranged from kappa = 0.85 to 0.96. One-month test-retest stability on the road test was 0.76 (quantitative scoring) and 0.53 (clinical judgment). CONCLUSIONS: Dementia adversely affects driving performance even in its mild stages, although some persons with DAT seem to drive safely for some time after disease onset. A traffic-interactive, performance-based road test that examines cognitive behaviors provides an accurate and reliable functional assessment of driving ability.

Aged↗
PubMed1997

Inhibitory control during sentence comprehension in individuals with dementia of the Alzheimer type.

In two experiments we investigated the extent to which individuals with dementia of the Alzheimer type (DAT) manage the activation of contextually appropriate and inappropriate meanings of ambiguous words during sentence comprehension. DAT individuals and healthy older individuals read sentences that ended in ambiguous words and then determined if a test word fit the overall meaning of the sentence. Analysis of response latencies indicated that DAT individuals were less efficient than healthy older individuals at suppressing inappropriate meanings of ambiguous words not implied by sentence context, but enhanced appropriate meanings to the same extent, if not more, than healthy older adults. DAT individuals were also more likely to allow inappropriate information to actually drive responses (i.e., increased intrusion errors). Overall, the results are consistent with a growing number of studies demonstrating impairments in inhibitory control, with relative preservation of facilitatory processes, in DAT.

Aged↗
PubMed1997

Environmental cueing may effect performance on a road test for drivers with dementia of the Alzheimer type.

This paper examines the impact of environmental cueing on a road test for persons with dementia of the Alzheimer type (DAT). In an earlier study, we demonstrated the reliability and stability of the Washington University Road Test in a sample of 58 healthy elderly controls and 65 subjects with DAT. We found that dementia adversely affects driving performance even in its mild stages. Here were elaborate on the results of a follow-up road test conducted 1 month after the baseline test (n = 63) explore possible reasons why the stability of the follow-up road test was lower than expected. We conclude that environmental cueing may affect performance on a road test in DAT.

Aged↗
PubMed1997

The role of selective attention in driving and dementia of the Alzheimer type.

This paper examines the relationship between cognitive processes and driving in aging and dementia of the Alzheimer type. Several studies that have explored the relationship between neuropsychological test performance and various indicators of driving safety are reviewed. It is argued that deficits in selective attention are specific to impaired driving performance in dementia of the Alzheimer type. Results from a recent study supporting this notion are presented. It is suggested that screening measures that emphasize the ability to selectively attend to relevant information and inhibit irrelevant information should be used to identify mildly demented individuals who are at risk for unsafe driving.

Alzheimer Disease↗
PubMed1991

Paired associate learning in senile dementia of the Alzheimer type.

A study was conducted to examine the potential explicit learning ability in senile dementia of the Alzheimer type (SDAT) as a function of (1) the difficulty of the to-be-remembered material and (2) the severity of the dementia. The Associate Learning task from the Wechsler Memory Scale was administered to healthy older adults and individuals with questionable, mild, and moderate SDAT. Individuals with SDAT showed poorer learning performance across trials than healthy older adults. Individuals with questionable and mild SDAT did show evidence for learning across trials for highly related paired associates. For unrelated-paired associates, however, only individuals with questionable SDAT showed some evidence for increased learning across trials.

Alzheimer Disease↗
PubMed1991

Semantic priming effects, lexical repetition effects, and contextual disambiguation effects in healthy aged individuals and individuals with senile dementia of the Alzheimer type.

An experiment is reported that addresses semantic priming effects, lexical repetition effects, and the influence of context on meaning selection for ambiguous words in 32 healthy aged individuals and 32 individuals with Senile Dementia of the Alzheimer Type (SDAT). On each of 232 trials, subjects pronounced each of three words. The four major conditions were concordant (music-organ-piano), discordant (kidney-organ-piano), neutral (ceiling-organ-piano), and unrelated (kidney-ceiling-piano). In order to address lexical repetition effects, target words were repeated across Blocks 1 and 2 but not in Block 3. Analyses of naming latencies indicated that semantic priming effects and lexical repetition effects were slightly larger in SDAT individuals than in healthy aged individuals. More importantly, healthy aged individuals produced normal selective access of the contextually biased meaning whereas SDAT individuals produced evidence consistent with nonselective meaning access. These results are discussed within both an attentional and a connectionist account of homograph disambiguation.

Aged↗
PubMed1991

Senile dementia and healthy aging: a longitudinal CT study.

Volumetric indexes of cerebral atrophy obtained by using computed tomography (CT) were measured longitudinally in patients with senile dementia of the Alzheimer type (SDAT) and in healthy elderly control subjects. Measurements were made three times over a 51-month period. Of the original 44 patients with SDAT, five were available for CT examination at the last time of assessment (51 months); in contrast, 41 of the original 58 control subjects were still available for study at 51 months. As a group, scans of SDAT subjects showed greater atrophy than those of control subjects in all volumetric indexes at each time of testing and demonstrated greater progression of atrophy during the study period. However, the overlap of indexes between the patients with SDAT and the control subjects indicates that CT data cannot be used alone to predict the presence or progression of dementia in individual cases.

Aged↗
PubMed1989

Age-related differences in the impact of spacing, lag, and retention interval.

An experiment is reported that examines age-related differences in the lag effect and its relation to retention interval. A total of 30 young and 30 older adults received both once-presented pairs and twice-presented pairs that were tested in a continuous cued-recall paradigm either after a short retention interval (2 pairs intervening between the last presentation of a pair and its test) or a long retention interval (20 pairs intervening between the last presentation of a pair and its test). In addition, the twice-presented pairs were separated by either 0, 1, 4, 8, or 20 intervening pairs. The results replicated the interaction between retention interval and lag that has been reported by Glenberg (1976, Journal of Verbal Learning and Verbal Behavior, 15, 1-16). Furthermore, although the older adults performed considerably lower than the younger adults in overall recall performance, their data were remarkably similar to the younger adults in the patterning of means. A mathematical modeling procedure was used to fit the data to Estes' stimulus fluctuation model. The results of this modeling procedure suggest that, compared with younger adults, older adults (a) encode less contextual information at a given point in time and (b) have a slower rate of contextual fluctuation across time.

Adult↗
PubMed1989

Spreading activation in episodic memory: further evidence for age independence.

Seventy-two young (mean age = 25 years) and 72 old adults (mean age = 71 years) participated in an experiment that addressed the influence of episodic and semantic prime activation on speeded episodic recognition judgements. On each test block, subjects studied two paragraphs at their own pace to achieve a designated level of episodic recognition performance. Following the study period, subjects were presented a series of prime-target trials for speeded episodic recognition. The primes were either (a) episodically related to the target, (b) semantically related to the target, (c) episodically and semantically related to the target, or (d) episodically and semantically unrelated to the target. The stimulus onset asynchrony (SOA) between the primes and targets was either 200 msec, 600 msec, or 1000 msec to address age-related changes in the rate at which these different prime types influenced performance. The results indicated that, compared to young adults, the old adults (a) studied the paragraphs for a longer period of time, (b) responded to the targets more slowly, and (c) were less accurate in their episodic recognition decisions. Although there were these main effects of age, the young and old adults were influenced in a similar fashion by the different prime-target relationships and by the interactive influences of the prime-target relationships and SOA. Correlational analyses indicated that the pattern of priming effects was as similar across the two age groups as across two pseudo-groups that were matched on the age dimension. These results were viewed as further support for the notion that the characteristics of the spreading activation mechanism as reflected by prime-target manipulations are relatively stable across young and old adults.

Adolescent↗
PubMed1989

A dissociative word-frequency X levels-of-processing interaction in episodic recognition and lexical decision tasks.

The effects of levels-of-processing and word frequency were directly compared in three different memory tests. In the episodic recognition test, the subjects decided whether or not a word or a pronounceable nonword had been previously studied. In the two lexical decision tests with either pronounceable or unpronounceable nonwords as distractors, the subjects decided whether a test item was a word or a nonword. There were four main results: (1) in all three tests, reaction times (RTs) in response to studied words were faster if they had received semantic rather than rhyme processing during study; (2) in the episodic recognition test, RTs were faster for low- than for high-frequency words; in both lexical decision tests, RTs were faster for high- than for low-frequency words, though less so when the nonword distractors were unpronounceable; (3) prior study facilitated lexical decisions more in response to low- than to high-frequency words, thereby attenuating the word-frequency effect, but more so when the nonword distractors were pronounceable; (4) in the lexical decision test with pronounceable nonword distractors, relative to prior rhyme processing, prior semantic processing facilitated performance more for high- than for low-frequency words, whereas the opposite was the case in the episodic recognition test. Discussion focused on the relationship of these results to current views of the mechanisms by which (1) word frequency and depth of processing affect performance in implicit and explicit memory tests, and (2) repetition priming attenuates word-frequency effects for lexical decisions.

Adult↗
PubMed1988

Age-related differences in lexical access, spreading activation, and simple pronunciation.

An experiment was conducted to address age-related differences in lexical access, spreading activation, and pronunciation. Both young and older adults participated in a delayed pronunciation task to trace the time course of lexical access and a semantic priming task to trace the time course of spreading activation. In the delayed pronunciation task, subjects were presented a word and then, after varying delays, were presented a cue to pronounce the word aloud. Older adults benefited considerably more from the preexposure to the word than did the younger adults, suggesting an age-related difference in lexical access time. In the semantic priming pronunciation task, semantic relatedness (related vs. neutral), strength of the relationship (high vs. low), and prime-target stimulus onset asynchrony (200 ms, 350 ms, 500 ms, 650 ms, and 800 ms) were factorially crossed with age to investigate age-related differences in the buildup of semantic activation across time. The results from this task indicated that the activation pattern of the older adults closely mimicked that of the younger adults. Finally, the results of both tasks indicated that older adults were slower at both their onset to pronounce and their actual production durations (i.e., from onset to offset) in the pronunciation task. The results were interpreted as suggesting that input and output processes are slowed with age, but that the basic retrieval mechanism of spreading activation is spared by age.

Adolescent↗
PubMed1986

Voice-specific information and the 20-second delayed-suffix effect.

Two experiments were conducted to investigate the nature of the delayed-suffix effect reported by Watkins and Todres (1980). In both experiments, subjects were presented lists of digits for serial recall. At the end of each list either a tone or a voice reading aloud the word go was presented. The voice was either in the same voice that read the digits or in a different voice. Past research has indicated that the tone control produces the least interference, followed by the different-voice suffix, which in turn produces less interference than the same-voice suffix. The results of both experiments indicated that when subjects were tested on immediate recall for the lists, the typical ordering of tone control, different-voice suffix, and same-voice suffix on recall at the last serial position was found. However, when there was a 20-s filled interval between the last list item and the suffix, there was only a difference between the tone control and the same- and different-voice suffixes with no difference between the latter two conditions. In addition, Experiment 2 failed to support a simple attentional account of the differential influence of voice in the immediate and delayed-recall conditions. The results are viewed as supporting a perceptual tuning mechanism in which perceptual specificity decreases with the passage of time.

Adolescent↗