Janet Duchek | Washington University in St. Louis (original) (raw)

Papers by Janet Duchek

Psychology and Aging, 2010

Past studies have suggested attentional control tasks such as the Stroop task and the task-switch... more Past studies have suggested attentional control tasks such as the Stroop task and the task-switching paradigm may be sensitive for the early detection of dementia of the Alzheimer's type (DAT). The authors of the current study combined these tasks to create a Stroop switching task. Performance was compared across young adults, older adults, and individuals diagnosed with very mild dementia. Results indicated that this task strongly discriminated individuals with healthy aging from those with early-stage DAT. In a logistic regression analysis, incongruent error rates from the Stroop switching task discriminated healthy aging from DAT better than any of the other 18 cognitive tasks given in a psychometric battery.

This study examined differences in personality in the earliest stages of dementia of the Alzheime... more This study examined differences in personality in the earliest stages of dementia of the Alzheimer type (DAT) relative to healthy aging, and the power of personality in discriminating healthy aging from early-stage DAT. Four groups of participants (middle-aged controls, older controls, persons with very mild DAT, and persons with mild DAT) and their families were administered Costa and McCrae's NEO

As the number of drivers with cognitive impairment increases, family physicians are more likely t... more As the number of drivers with cognitive impairment increases, family physicians are more likely to become involved in decisions about cessation of driving privileges in older patients. Physi- cians who care for cognitively impaired older adults should routinely ask about driving status. In patients who continue to drive, physicians should assess pertinent cognitive domains, deter- mine the severity and etiology

Personality and Individual Differences, 2015

Association studies between the NEO five factor personality inventory and COMT rs4680 have focuse... more Association studies between the NEO five factor personality inventory and COMT rs4680 have focused on young adults and the results have been inconsistent. However, personality and cortical changes with age may put older adults in a more sensitive range for detecting a relationship. The present study examined associations of COMT rs4680 and personality in older adults.

Psychology and Aging, 2010

In the present study, we investigated which cognitive functions in older adults at Time A are pre... more In the present study, we investigated which cognitive functions in older adults at Time A are predictive of conversion to dementia of the Alzheimer’s type (DAT) at Time B. Forty-seven healthy individuals were initially tested in 1992–1994 on a trial-by-trial computerized Stroop task along with a battery of psychometric measures that tap general knowledge, declarative memory, visual–spatial processing, and processing

Psychology and Aging, 2006

Three experiments explored different schedules of retrieval practice in young adults, older adult... more Three experiments explored different schedules of retrieval practice in young adults, older adults, and individuals with dementia of the Alzheimer type. In each experiment, an initial acquisition phase was presented in which participants studied or attempted to retrieve response words to cues, followed by a later cued-recall test. Experiment 1 produced a benefit of expanded retrieval over equal-interval retrieval during acquisition, but this benefit was lost in final cued recall. In Experiments 2 and 3, participants received corrective feedback during acquisition and modified spacing schedules. There was again no evidence of a difference between expanded and equal-interval conditions in final cued recall. Discussion focuses on the potential benefits and costs of expanded retrieval on a theoretical and applied level.

The present chapter provides a review of the literature addressing changes in memory performance ... more The present chapter provides a review of the literature addressing changes in memory performance in older adults (often retired individuals with an age between 60 and 80 years), compared to younger adults (often college students around age 20). While it is well-established that memory performance declines in older adults (e.g., Kausler, 1994;, it is now clear that not all aspects of memory are impaired (e.

Radiology, 1991

ABSTRACT Volumetric indexes of cerebral atrophy obtained by using computed tomography (CT) were m... more ABSTRACT 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.

Alzheimer Disease & Associated Disorders, 1997

Page 1. Alzheimer Disease and Associated Disorders Vol. 11, Suppl. 1, pp. 13-16 © 1997 Lippincott... more Page 1. Alzheimer Disease and Associated Disorders Vol. 11, Suppl. 1, pp. 13-16 © 1997 Lippincott-Raven Publishers, Philadelphia Environmental Cueing May Affect Performance on a Road Test for Drivers with Dementia of ...

The Quarterly Journal of Experimental Psychology Section A, 1989

Seventy-two young (mean age = 25 years) and 72 old adults (mean age = 71 years) participated in a... more 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.

Psychology and Aging, 1989

An experiment is reported that examines age-related differences in the lag effect and its relatio... more 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.

Psychology and Aging, 2011

Psychology and Aging, 1988

An experiment was conducted to address age-related differences in lexical access, spreading activ... more 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.

Neuropsychology, 2005

The authors examined the right ear advantage in a dichotic listening task in healthy aging and ve... more The authors examined the right ear advantage in a dichotic listening task in healthy aging and very mild and mild stages of Alzheimer's disease. Subjects were simultaneously presented 3 pairs of digits to the left and right ears (e.g., left ear: 4, 3, 1; right ear: 9, 2, 5) for immediate ordered recall. Four lists of triads were presented, varying in presentation rate between digit pairs within a triad (0.5, 1.0, 1.5, 2.0 s). Results indicated that the very mild and mild Alzheimer's groups showed a larger right ear advantage in free recall compared with the healthy controls, indicating a tendency to respond to the prepotent left hemisphere pathway for language processing. Also, the right ear advantage and proportion of switches made during recall were correlated with psychometric measures of frontal lobe function in the mild Alzheimer's group but not in the very mild or healthy control groups.

Neuropsychology, 2010

The present study explored the ability to control familiarity-based information in a memory exclu... more The present study explored the ability to control familiarity-based information in a memory exclusion paradigm in healthy young, older adults, and early stage DAT individuals. The authors compared the predictive power of memory exclusion performance to standard psychometric performance in discriminating between healthy aging and the earliest detectable form of DAT and between APOe4-present and APOe4-absent genotype in healthy control individuals. Participants responded "yes" to words that were previously semantically encoded, and "no" to other words. The number of targets and distractors on the read "distractor" list was manipulated to investigate the degree to which aging and DAT influence the ability to recollect specific details of study episodes in the face of distractor familiarity because of repetition. Memory exclusion performance (as reflected by dЈ) decreased across participant groups (young Ͼ healthy old control Ͼ very mild DAT). Logistic regression analyses showed that dЈ increased the discriminative power for healthy older adults versus very mild DAT individuals above and beyond standard psychometric measures. Memory exclusion dЈ was also lower for healthy control individuals with APOe4 allele, compared to those without the APOe4 allele after partialing out baseline psychometric performance. Discussion focuses on the importance of attentional control systems in memory retrieval and the utility of the opposition paradigm for early discrimination between healthy and pathological aging.

Neuropsychology, 2010

The characteristics of response time (RT) distributions beyond measures of central tendency were ... more The characteristics of response time (RT) distributions beyond measures of central tendency were explored in 3 attention tasks across groups of young adults, healthy older adults, and individuals with very mild dementia of the Alzheimer's type (DAT). Method: Participants were administered computerized Stroop, Simon, and switching tasks, along with psychometric tasks that tap various cognitive abilities and a standard personality inventory (NEO-FFI). Ex-Gaussian (and Vincentile) analyses were used to capture the characteristics of the RT distributions for each participant across the 3 tasks, which afforded 3 components: and (mean and standard deviation of the modal portion of the distribution) and (the positive tail of the distribution). Results: The results indicated that across all 3 attention tasks, healthy aging produced large changes in the central tendency parameter of the distribution along with some change in and (mean p 2 ϭ .17, .08, and .04, respectively). In contrast, early stage DAT primarily produced an increase in the component (mean p 2 ϭ .06). was also correlated with the psychometric measures of episodic/semantic memory, working memory, and processing speed, and with the personality traits of neuroticism and conscientiousness. Structural equation modeling indicated a unique relation between a latent construct (-.90), as opposed to (-.09) and constructs (.24), with working memory measures. Conclusions: The results suggest a critical role of attentional control systems in discriminating healthy aging from early stage DAT and the utility of RT distribution analyses to better specify the nature of such change.

Neuropsychology, 2009

This study explored differences in intraindividual variability in 3 attention tasks across a larg... more This study explored differences in intraindividual variability in 3 attention tasks across a large sample of healthy older adults and individuals with very mild dementia of the Alzheimer's type (DAT). Three groups of participants (healthy young adults, healthy older adults, very mild DAT) were administered 3 experimental measures of attentional selection and switching (Stroop, Simon, task switching). The results indicated that a measure of intraindividual variability, coefficient of variation (CoV; SD/M), increased across age and early stage DAT. The CoV in Stroop discriminated the performance of ε4 carriers from noncarriers in healthy older controls and the CoV in task switching was correlated with cerebrospinal fluid (CSF) biomarkers predictive of DAT.

Neuropsychology, 2006

The present study examined whether prospective memory performance discriminates healthy aging fro... more The present study examined whether prospective memory performance discriminates healthy aging from very mild dementia of the Alzheimer type (DAT) and individuals at risk for DAT due to the presence of the ApoE ε4 allele. Four groups of subjects (young adults, young-old controls, old-old controls, very mild DAT) engaged in an event-based prospective memory task wherein they responded to a specific word embedded in a general knowledge test. Results indicated that prospective memory performance was clearly impaired in the very mild DAT group relative to the healthy older control groups. Moreover, prospective memory performance appears to capture unique variance in discriminating these two groups above and beyond standard retrospective memory tests. However, prospective memory was not affected by ApoE status in the young-old control group and contrary to predictions, the ε4 + old-old controls showed better performance than the ε4 -subjects. In contrast to the healthy individuals, in the very mild DAT group, ε4 + subjects showed deficits in performance relative to the ε4 -subjects. Discussion focuses on prospective memory as a cognitive indicator of early stage DAT.

Neuropsychology, 2013

Early biomarkers of Alzheimer&amp... more Early biomarkers of Alzheimer's disease (AD) are needed for developing therapeutic interventions. Measures of attentional control in Stroop-type tasks discriminate healthy aging from early stage AD and predict future development of AD in cognitively normal individuals. Disruption in resting state functional connectivity MRI (rs-fcMRI) has been reported in AD and in healthy controls at risk for AD. We explored the relationship among Stroop performance, rs-fcMRI, and CSF Aβ₄₂ levels in cognitively normal older adults. A computerized Stroop task (along with standard neuropsychological measures), rs-fcMRI, and CSF were obtained in 237 cognitively normal older adults. We compared the relationship between Stroop performance, including measures from reaction distributional analyses, and composite scores from four resting state networks (RSNs; default mode [DMN], salience [SAL], dorsal attention [DAN], and sensory-motor [SMN]), and the modulatory influence of CSF Aβ₄₂ levels. A larger Stroop effect in errors was associated with reduced rs-fcMRI within the DMN and SAL. Reaction time (RT) distributional analyses indicated the slow tail of the RT distribution was related to reduced rs-fcMRI functional connectivity within the SAL. Standard psychometric measures were not related to RSN composite scores. A relationship between Stroop performance and DMN (but not SAL) functional connectivity was stronger in CSF Aβ₄₂-positive individuals. A link exists between RSN composite scores and specific attentional performance measures. Both measures may be sensitive biomarkers for AD.

Neuropsychology, 1994

The present experiment examined different components of motor control that may be impaired in nor... more The present experiment examined different components of motor control that may be impaired in normal aging, senile dementia of the Alzheimer type (SDAT), and Parkinson's disease (PD). Specifically, A. M. Wing and A. B. Kristofferson's (1973) formal quantitative model of rhythmic finger tapping was used to obtain estimates of central timekeeping and response execution components of timing control. Subjects included

Psychology and Aging, 2010

Past studies have suggested attentional control tasks such as the Stroop task and the task-switch... more Past studies have suggested attentional control tasks such as the Stroop task and the task-switching paradigm may be sensitive for the early detection of dementia of the Alzheimer's type (DAT). The authors of the current study combined these tasks to create a Stroop switching task. Performance was compared across young adults, older adults, and individuals diagnosed with very mild dementia. Results indicated that this task strongly discriminated individuals with healthy aging from those with early-stage DAT. In a logistic regression analysis, incongruent error rates from the Stroop switching task discriminated healthy aging from DAT better than any of the other 18 cognitive tasks given in a psychometric battery.

This study examined differences in personality in the earliest stages of dementia of the Alzheime... more This study examined differences in personality in the earliest stages of dementia of the Alzheimer type (DAT) relative to healthy aging, and the power of personality in discriminating healthy aging from early-stage DAT. Four groups of participants (middle-aged controls, older controls, persons with very mild DAT, and persons with mild DAT) and their families were administered Costa and McCrae's NEO

As the number of drivers with cognitive impairment increases, family physicians are more likely t... more As the number of drivers with cognitive impairment increases, family physicians are more likely to become involved in decisions about cessation of driving privileges in older patients. Physi- cians who care for cognitively impaired older adults should routinely ask about driving status. In patients who continue to drive, physicians should assess pertinent cognitive domains, deter- mine the severity and etiology

Personality and Individual Differences, 2015

Association studies between the NEO five factor personality inventory and COMT rs4680 have focuse... more Association studies between the NEO five factor personality inventory and COMT rs4680 have focused on young adults and the results have been inconsistent. However, personality and cortical changes with age may put older adults in a more sensitive range for detecting a relationship. The present study examined associations of COMT rs4680 and personality in older adults.

Psychology and Aging, 2010

In the present study, we investigated which cognitive functions in older adults at Time A are pre... more In the present study, we investigated which cognitive functions in older adults at Time A are predictive of conversion to dementia of the Alzheimer’s type (DAT) at Time B. Forty-seven healthy individuals were initially tested in 1992–1994 on a trial-by-trial computerized Stroop task along with a battery of psychometric measures that tap general knowledge, declarative memory, visual–spatial processing, and processing

Psychology and Aging, 2006

Three experiments explored different schedules of retrieval practice in young adults, older adult... more Three experiments explored different schedules of retrieval practice in young adults, older adults, and individuals with dementia of the Alzheimer type. In each experiment, an initial acquisition phase was presented in which participants studied or attempted to retrieve response words to cues, followed by a later cued-recall test. Experiment 1 produced a benefit of expanded retrieval over equal-interval retrieval during acquisition, but this benefit was lost in final cued recall. In Experiments 2 and 3, participants received corrective feedback during acquisition and modified spacing schedules. There was again no evidence of a difference between expanded and equal-interval conditions in final cued recall. Discussion focuses on the potential benefits and costs of expanded retrieval on a theoretical and applied level.

The present chapter provides a review of the literature addressing changes in memory performance ... more The present chapter provides a review of the literature addressing changes in memory performance in older adults (often retired individuals with an age between 60 and 80 years), compared to younger adults (often college students around age 20). While it is well-established that memory performance declines in older adults (e.g., Kausler, 1994;, it is now clear that not all aspects of memory are impaired (e.

Radiology, 1991

ABSTRACT Volumetric indexes of cerebral atrophy obtained by using computed tomography (CT) were m... more ABSTRACT 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.

Alzheimer Disease & Associated Disorders, 1997

Page 1. Alzheimer Disease and Associated Disorders Vol. 11, Suppl. 1, pp. 13-16 © 1997 Lippincott... more Page 1. Alzheimer Disease and Associated Disorders Vol. 11, Suppl. 1, pp. 13-16 © 1997 Lippincott-Raven Publishers, Philadelphia Environmental Cueing May Affect Performance on a Road Test for Drivers with Dementia of ...

The Quarterly Journal of Experimental Psychology Section A, 1989

Seventy-two young (mean age = 25 years) and 72 old adults (mean age = 71 years) participated in a... more 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.

Psychology and Aging, 1989

An experiment is reported that examines age-related differences in the lag effect and its relatio... more 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.

Psychology and Aging, 2011

Psychology and Aging, 1988

An experiment was conducted to address age-related differences in lexical access, spreading activ... more 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.

Neuropsychology, 2005

The authors examined the right ear advantage in a dichotic listening task in healthy aging and ve... more The authors examined the right ear advantage in a dichotic listening task in healthy aging and very mild and mild stages of Alzheimer's disease. Subjects were simultaneously presented 3 pairs of digits to the left and right ears (e.g., left ear: 4, 3, 1; right ear: 9, 2, 5) for immediate ordered recall. Four lists of triads were presented, varying in presentation rate between digit pairs within a triad (0.5, 1.0, 1.5, 2.0 s). Results indicated that the very mild and mild Alzheimer's groups showed a larger right ear advantage in free recall compared with the healthy controls, indicating a tendency to respond to the prepotent left hemisphere pathway for language processing. Also, the right ear advantage and proportion of switches made during recall were correlated with psychometric measures of frontal lobe function in the mild Alzheimer's group but not in the very mild or healthy control groups.

Neuropsychology, 2010

The present study explored the ability to control familiarity-based information in a memory exclu... more The present study explored the ability to control familiarity-based information in a memory exclusion paradigm in healthy young, older adults, and early stage DAT individuals. The authors compared the predictive power of memory exclusion performance to standard psychometric performance in discriminating between healthy aging and the earliest detectable form of DAT and between APOe4-present and APOe4-absent genotype in healthy control individuals. Participants responded "yes" to words that were previously semantically encoded, and "no" to other words. The number of targets and distractors on the read "distractor" list was manipulated to investigate the degree to which aging and DAT influence the ability to recollect specific details of study episodes in the face of distractor familiarity because of repetition. Memory exclusion performance (as reflected by dЈ) decreased across participant groups (young Ͼ healthy old control Ͼ very mild DAT). Logistic regression analyses showed that dЈ increased the discriminative power for healthy older adults versus very mild DAT individuals above and beyond standard psychometric measures. Memory exclusion dЈ was also lower for healthy control individuals with APOe4 allele, compared to those without the APOe4 allele after partialing out baseline psychometric performance. Discussion focuses on the importance of attentional control systems in memory retrieval and the utility of the opposition paradigm for early discrimination between healthy and pathological aging.

Neuropsychology, 2010

The characteristics of response time (RT) distributions beyond measures of central tendency were ... more The characteristics of response time (RT) distributions beyond measures of central tendency were explored in 3 attention tasks across groups of young adults, healthy older adults, and individuals with very mild dementia of the Alzheimer's type (DAT). Method: Participants were administered computerized Stroop, Simon, and switching tasks, along with psychometric tasks that tap various cognitive abilities and a standard personality inventory (NEO-FFI). Ex-Gaussian (and Vincentile) analyses were used to capture the characteristics of the RT distributions for each participant across the 3 tasks, which afforded 3 components: and (mean and standard deviation of the modal portion of the distribution) and (the positive tail of the distribution). Results: The results indicated that across all 3 attention tasks, healthy aging produced large changes in the central tendency parameter of the distribution along with some change in and (mean p 2 ϭ .17, .08, and .04, respectively). In contrast, early stage DAT primarily produced an increase in the component (mean p 2 ϭ .06). was also correlated with the psychometric measures of episodic/semantic memory, working memory, and processing speed, and with the personality traits of neuroticism and conscientiousness. Structural equation modeling indicated a unique relation between a latent construct (-.90), as opposed to (-.09) and constructs (.24), with working memory measures. Conclusions: The results suggest a critical role of attentional control systems in discriminating healthy aging from early stage DAT and the utility of RT distribution analyses to better specify the nature of such change.

Neuropsychology, 2009

This study explored differences in intraindividual variability in 3 attention tasks across a larg... more This study explored differences in intraindividual variability in 3 attention tasks across a large sample of healthy older adults and individuals with very mild dementia of the Alzheimer's type (DAT). Three groups of participants (healthy young adults, healthy older adults, very mild DAT) were administered 3 experimental measures of attentional selection and switching (Stroop, Simon, task switching). The results indicated that a measure of intraindividual variability, coefficient of variation (CoV; SD/M), increased across age and early stage DAT. The CoV in Stroop discriminated the performance of ε4 carriers from noncarriers in healthy older controls and the CoV in task switching was correlated with cerebrospinal fluid (CSF) biomarkers predictive of DAT.

Neuropsychology, 2006

The present study examined whether prospective memory performance discriminates healthy aging fro... more The present study examined whether prospective memory performance discriminates healthy aging from very mild dementia of the Alzheimer type (DAT) and individuals at risk for DAT due to the presence of the ApoE ε4 allele. Four groups of subjects (young adults, young-old controls, old-old controls, very mild DAT) engaged in an event-based prospective memory task wherein they responded to a specific word embedded in a general knowledge test. Results indicated that prospective memory performance was clearly impaired in the very mild DAT group relative to the healthy older control groups. Moreover, prospective memory performance appears to capture unique variance in discriminating these two groups above and beyond standard retrospective memory tests. However, prospective memory was not affected by ApoE status in the young-old control group and contrary to predictions, the ε4 + old-old controls showed better performance than the ε4 -subjects. In contrast to the healthy individuals, in the very mild DAT group, ε4 + subjects showed deficits in performance relative to the ε4 -subjects. Discussion focuses on prospective memory as a cognitive indicator of early stage DAT.

Neuropsychology, 2013

Early biomarkers of Alzheimer&amp... more Early biomarkers of Alzheimer's disease (AD) are needed for developing therapeutic interventions. Measures of attentional control in Stroop-type tasks discriminate healthy aging from early stage AD and predict future development of AD in cognitively normal individuals. Disruption in resting state functional connectivity MRI (rs-fcMRI) has been reported in AD and in healthy controls at risk for AD. We explored the relationship among Stroop performance, rs-fcMRI, and CSF Aβ₄₂ levels in cognitively normal older adults. A computerized Stroop task (along with standard neuropsychological measures), rs-fcMRI, and CSF were obtained in 237 cognitively normal older adults. We compared the relationship between Stroop performance, including measures from reaction distributional analyses, and composite scores from four resting state networks (RSNs; default mode [DMN], salience [SAL], dorsal attention [DAN], and sensory-motor [SMN]), and the modulatory influence of CSF Aβ₄₂ levels. A larger Stroop effect in errors was associated with reduced rs-fcMRI within the DMN and SAL. Reaction time (RT) distributional analyses indicated the slow tail of the RT distribution was related to reduced rs-fcMRI functional connectivity within the SAL. Standard psychometric measures were not related to RSN composite scores. A relationship between Stroop performance and DMN (but not SAL) functional connectivity was stronger in CSF Aβ₄₂-positive individuals. A link exists between RSN composite scores and specific attentional performance measures. Both measures may be sensitive biomarkers for AD.

Neuropsychology, 1994

The present experiment examined different components of motor control that may be impaired in nor... more The present experiment examined different components of motor control that may be impaired in normal aging, senile dementia of the Alzheimer type (SDAT), and Parkinson's disease (PD). Specifically, A. M. Wing and A. B. Kristofferson's (1973) formal quantitative model of rhythmic finger tapping was used to obtain estimates of central timekeeping and response execution components of timing control. Subjects included