Dustin Hammers

University of Utah, Salt Lake City, Utah, United States

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Publications (9)44.35 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Limited research exists to explain differential executive functioning impairment in clinical populations, particularly between the Wisconsin Card Sorting Task (WCST) and the Trail Making Test (TMT). The distribution of clinical diagnoses was examined in patients failing none, one, or both tasks, and executive task performance was compared among dementia-related diagnoses. Two hundred and sixty-six participants received evaluations through an Alzheimer's Disease Research Center, which included executive tasks. Dementia-related diagnoses were established through consensus. Chi-square analyses indicated that TMT failure, with or without WCST failure, possessed higher associations with dementia diagnoses. Repeated measures analysis of variance similarly indicated that participants with dementia, especially mild and moderate severity, performed worse on TMT. Executive dysfunction was observed in dementia-related diagnoses, and TMT failure was implicated in dementia in higher proportions than WCST impairment. Trail Making Test appears more sensitive than WCST for assessing executive impairment across diagnoses, especially when time and resources are limited in screening and clinical settings. © The Author(s) 2015.
    American Journal of Alzheimer s Disease and Other Dementias 09/2015; DOI:10.1177/1533317515603114 · 1.63 Impact Factor
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    ABSTRACT: Although amyloid deposition remains a marker of the development of Alzheimer's disease, results linking amyloid and cognition have been equivocal. Twenty-five community-dwelling non-demented older adults were examined with (18)F-flutemetamol, an amyloid imaging agent, and a cognitive battery, including an estimate of premorbid intellect and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). In the first model, (18)F-flutemetamol uptake significantly correlated with the Delayed Memory Index of the RBANS (r = -.51, p = .02) and premorbid intellect (r = .43, p = .03). In the second model, the relationship between (18)F-flutemetamol and cognition was notably stronger when controlling for premorbid intellect (e.g., three of the five RBANS Indexes and its Total score significantly correlated with (18)F-flutemetamol, r's = -.41 to -.58). Associations were found between amyloid-binding (18)F-flutemetamol and cognitive functioning in non-demented older adults. These associations were greatest with delayed memory and stronger when premorbid intellect was considered, suggesting that cognitive reserve partly compensates for the symptomatic expression of amyloid pathology in community-dwelling elderly.
    Archives of Clinical Neuropsychology 06/2013; 28(7). DOI:10.1093/arclin/act047 · 1.99 Impact Factor
  • Neurology 09/2012; 79(11):E88-E89. · 8.29 Impact Factor
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    ABSTRACT: BACKGROUND:: The self-care regimen necessary in heart failure (HF) is notably complex. A complication to integrating new knowledge and behaviors is that impaired cognition has been frequently reported in patients with HF, which significantly impacts patients' health, admission and mortality rates, and instrumental activities of daily living. OBJECTIVE:: The identification of reliable cognitive screening tools to assess potential difficulties in performing self-care for cardiac populations is essential. As such, the current purposes were to evaluate the validity and stability of the International Shopping List (ISL) auditory learning subtest from the computerized CogState battery as a screening tool in HF populations, determine the ISL's ability to predict functional declines, and evaluate the task's sensitivity in myocardial infarction. METHODS:: Forty patients with chronic HF were enrolled in a longitudinal study evaluating the impact of a cognitive training intervention. Baseline neuropsychological and behavioral measurements before treatment were used in the current study, including measures of auditory memory, orientation, verbal fluency, processing speed, and activities of daily living, and a subset of patients (n = 17) received repeat testing at 8 weeks on some tasks. Analyses also were performed with patients organized based on myocardial infarction status. RESULTS:: The current study indicated that the ISL performed comparably with an established measure of auditory memory (Hopkins Verbal Learning Test-Revised; r = 0.70, P < .001), displayed adequate coefficients of stability (r = 0.53-0.68), and successfully predicted declines over time in daily functioning (β = .47, P < .001) in our HF sample. CONCLUSIONS:: The computerized CogState auditory memory subtest, the ISL, seems to be a beneficial tool in evaluating cognitive change in HF patients. Particularly given its cross-cultural sensitivity and ease of administration and scoring, this task may provide assistance to quickly and reliably monitor memory functioning in these vulnerable patients and gauge their potential for self-care behaviors.
    The Journal of cardiovascular nursing 06/2012; 28(5). DOI:10.1097/JCN.0b013e318258abf3 · 2.05 Impact Factor
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    ABSTRACT: While preliminary evidence supports the criterion validity of the CogState computerized brief battery in mild cognitive impairment (MCI) and Alzheimer disease (AD), definitive validation studies examining a wider range of dementia-related disorders relative to conventional neuropsychological techniques are necessary. Participants satisfying clinical consensus criteria for dementia (AD, n = 37; frontotemporal dementia, n = 7; and dementia with Lewy bodies, n = 5), MCI (n = 16), and the healthy controls (n = 22) were administered a battery of brief neuropsychological and select computerized (CogState) cognitive tests. The battery, administered through the University of Michigan Alzheimer's Disease Research Center, included measures of processing speed, attention, working memory, and learning. CogState and standard neuropsychological task scores were significantly lower for dementia participants than that of the nondementia groups (P < .05), with a single CogState test distinguishing control from MCI participants, but minimal differentiation existing between dementias using the CogState. Correlations were modest between conventional and computerized test scores, covering matching domains and mostly reflecting the multidimensional nature of cognitive paradigms. Results support the clinical validity of this brief computerized screening battery when used in established dementias, but not to differentiate between various dementias, and suggest that the select CogState battery's effectiveness in identifying MCI from controls was not as strong as identifying specific dementias.
    Journal of Geriatric Psychiatry and Neurology 06/2012; 25(2):89-99. DOI:10.1177/0891988712447894 · 2.24 Impact Factor
  • Alzheimer's and Dementia 07/2011; 7(4). DOI:10.1016/j.jalz.2011.05.1514 · 12.41 Impact Factor
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    ABSTRACT: The aim of this study was to evaluate the short-term stability and reliability of a brief computerized cognitive battery in established dementia types. Patients were administered the computerized battery twice with administrations approximately 2 hours apart, with intervening conventional neuropsychological tests. Patients were classified clinically, via consensus conference, as healthy controls (n = 23), mild cognitive impairment (n = 20), Alzheimer's disease (n = 52), dementia with Lewy Bodies ([DLB], n = 10), or frontotemporal dementia (n = 9). Minimal practice effects were evident across Cog-State test administrations. Small magnitude improvements were seen across all groups on a working memory task, and healthy controls showed a mild practice effect on the accuracy of associative learning. In established dementia, administration of the CogState tasks appears sensitive to cognitive impairment in dementia. Repeat administration also provided acceptable stability and test-retest reliability with minimal practice effects at short test-retest intervals despite intervening cognitive challenges.
    American Journal of Alzheimer s Disease and Other Dementias 06/2011; 26(4):326-33. DOI:10.1177/1533317511411907 · 1.63 Impact Factor
  • Alzheimer's and Dementia 07/2010; 6(4). DOI:10.1016/j.jalz.2010.08.159 · 12.41 Impact Factor
  • The Clinical Neuropsychologist 01/2010; 24(4):577-577. · 1.72 Impact Factor

Publication Stats

23 Citations
44.35 Total Impact Points


  • 2013
    • University of Utah
      • Department of Neurology
      Salt Lake City, Utah, United States
  • 2011
    • University of Michigan
      • Department of Psychiatry
      Ann Arbor, Michigan, United States