Roger A Dixon

Summary

Affiliation: University of Alberta
Country: Canada

Publications

  1. ncbi request reprint Neurocognitive markers of cognitive impairment: exploring the roles of speed and inconsistency
    Roger A Dixon
    Department of Psychology, University of Alberta, Edmonton, Alberta, Canada
    Neuropsychology 21:381-99. 2007
  2. ncbi request reprint Mild memory deficits differentially affect 6-year changes in compensatory strategy use
    Roger A Dixon
    Department of Psychology, University of Alberta, Edmonton, Alberta, Canada
    Psychol Aging 22:632-8. 2007
  3. ncbi request reprint Episodic memory change in late adulthood: generalizability across samples and performance indices
    Roger A Dixon
    Department of Psychology, University of Alberta, Edmonton, Alberta, Canada
    Mem Cognit 32:768-78. 2004
  4. pmc Evaluating everyday competence in older adult couples: epidemiological considerations
    Roger A Dixon
    Department of Psychology, University of Alberta, Edmonton, Alta, Canada
    Gerontology 57:173-9. 2011
  5. ncbi request reprint Self-reported memory compensation: similar patterns in Alzheimer's disease and very old adult samples
    Roger A Dixon
    Department of Psychology, University of Alberta, Edmonton, Canada
    J Clin Exp Neuropsychol 25:382-90. 2003
  6. pmc Short-term longitudinal trends in cognitive performance in older adults with type 2 diabetes
    Ashley L Fischer
    Department of Psychology, University of Alberta, Edmonton, Alberta, Canada
    J Clin Exp Neuropsychol 31:809-22. 2009
  7. pmc Mild cognitive impairment is associated with selected functional markers: integrating concurrent, longitudinal, and stability effects
    Sanda Dolcos
    Department of Psychology, University of Alberta, Edmonton, Alberta, Canada
    Neuropsychology 26:209-23. 2012
  8. ncbi request reprint Age-related slowing of digit symbol substitution revisited: what do longitudinal age changes reflect?
    Stuart W S MacDonald
    Department of Psychology, University of Victoria, British Columbia, Canada
    J Gerontol B Psychol Sci Soc Sci 58:P187-94. 2003
  9. pmc Exploring effects of type 2 diabetes on cognitive functioning in older adults
    Sophie E Yeung
    Department of Psychology, University of Alberta, Edmonton, Alberta, Canada
    Neuropsychology 23:1-9. 2009
  10. pmc Linking biological and cognitive aging: toward improving characterizations of developmental time
    Stuart W S MacDonald
    Department of Psychology, University of Victoria, Victoria, Canada
    J Gerontol B Psychol Sci Soc Sci 66:i59-70. 2011

Detail Information

Publications34

  1. ncbi request reprint Neurocognitive markers of cognitive impairment: exploring the roles of speed and inconsistency
    Roger A Dixon
    Department of Psychology, University of Alberta, Edmonton, Alberta, Canada
    Neuropsychology 21:381-99. 2007
    ..Neurocognitive markers of speed and inconsistency may be leading indicators of emerging cognitive impairment...
  2. ncbi request reprint Mild memory deficits differentially affect 6-year changes in compensatory strategy use
    Roger A Dixon
    Department of Psychology, University of Alberta, Edmonton, Alberta, Canada
    Psychol Aging 22:632-8. 2007
    ..Interactions of group status and wave showed that older adults with MMD declined in their use of memory compensation strategies, whereas initially NIC older adults increased their use of compensatory techniques over the 6 years...
  3. ncbi request reprint Episodic memory change in late adulthood: generalizability across samples and performance indices
    Roger A Dixon
    Department of Psychology, University of Alberta, Edmonton, Alberta, Canada
    Mem Cognit 32:768-78. 2004
    ..The exception-greater decline for more supported tasks-suggests that these may be especially sensitive to late-life changes...
  4. pmc Evaluating everyday competence in older adult couples: epidemiological considerations
    Roger A Dixon
    Department of Psychology, University of Alberta, Edmonton, Alta, Canada
    Gerontology 57:173-9. 2011
    ....
  5. ncbi request reprint Self-reported memory compensation: similar patterns in Alzheimer's disease and very old adult samples
    Roger A Dixon
    Department of Psychology, University of Alberta, Edmonton, Canada
    J Clin Exp Neuropsychol 25:382-90. 2003
    ..Results are interpreted in terms of insight into changes in memory skills and inthe implementation of effective memory support systems...
  6. pmc Short-term longitudinal trends in cognitive performance in older adults with type 2 diabetes
    Ashley L Fischer
    Department of Psychology, University of Alberta, Edmonton, Alberta, Canada
    J Clin Exp Neuropsychol 31:809-22. 2009
    ..It is clinically and theoretically important to examine sequential change in multiple domains over time...
  7. pmc Mild cognitive impairment is associated with selected functional markers: integrating concurrent, longitudinal, and stability effects
    Sanda Dolcos
    Department of Psychology, University of Alberta, Edmonton, Alberta, Canada
    Neuropsychology 26:209-23. 2012
    ..We identified functional markers associated with differences, changes, and stability in cognitive status...
  8. ncbi request reprint Age-related slowing of digit symbol substitution revisited: what do longitudinal age changes reflect?
    Stuart W S MacDonald
    Department of Psychology, University of Victoria, British Columbia, Canada
    J Gerontol B Psychol Sci Soc Sci 58:P187-94. 2003
    ..These discrepancies suggest different sources of variance may underlie cross-sectional age differences and longitudinal age changes for DSS...
  9. pmc Exploring effects of type 2 diabetes on cognitive functioning in older adults
    Sophie E Yeung
    Department of Psychology, University of Alberta, Edmonton, Alberta, Canada
    Neuropsychology 23:1-9. 2009
    ..Notably, the diabetes-related effects were robust across the two late-life age groups. Future research examining longitudinal changes is recommended...
  10. pmc Linking biological and cognitive aging: toward improving characterizations of developmental time
    Stuart W S MacDonald
    Department of Psychology, University of Victoria, Victoria, Canada
    J Gerontol B Psychol Sci Soc Sci 66:i59-70. 2011
    ..The present investigation explores the potential that selected functional biomarkers may contribute to the more effective conceptual and operational definitions of developmental time...
  11. pmc Are neurocognitive speed and inconsistency similarly affected in type 2 diabetes?
    Bonnie P Whitehead
    Department of Psychology, University of Alberta, Edmonton, AB, Canada
    J Clin Exp Neuropsychol 33:647-57. 2011
    ..Fourth, we observed similar longitudinal change patterns for IM and ISD. Results are linked to the theoretical location of T2D on an adjusted neural vulnerability continuum...
  12. pmc Exploring cognitive effects of self reported mild stroke in older adults: selective but robust effects on story memory
    Laura Mansueti
    University of Alberta, Edmonton, Alberta, Canada, 2University of Victoria, Victoria, BC, Canada
    Neuropsychol Dev Cogn B Aging Neuropsychol Cogn 15:545-73. 2008
    ....
  13. ncbi request reprint Variability in reaction time performance of younger and older adults
    David F Hultsch
    Department of Psychology, University of Victoria, British Columbia, Canada
    J Gerontol B Psychol Sci Soc Sci 57:P101-15. 2002
    ..The results indicate that variability of performance is an important indicator of cognitive functioning and aging...
  14. pmc Testing covariates of Type 2 diabetes-cognition associations in older adults: moderating or mediating effects?
    G Peggy Mcfall
    Department of Psychology, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
    Neuropsychology 24:547-62. 2010
    ....
  15. ncbi request reprint Intraindividual variability in neurocognitive speed: a comparison of Parkinson's disease and normal older adults
    Cindy M de Frias
    Division of Neurology, University of Alberta, Edmonton, Alberta, Canada
    Neuropsychologia 45:2499-507. 2007
    ..Intraindividual variability was not correlated with tapping speed and gait speed in any group. Executive functioning and neurocognitive speed may be valid and distinct clinical markers of disease progression in PD...
  16. pmc Aging and the shape of cognitive change before death: terminal decline or terminal drop?
    Stuart W S MacDonald
    Department of Psychology, University of Victoria, Victoria, BC V8W 3P5, Canada
    J Gerontol B Psychol Sci Soc Sci 66:292-301. 2011
    ..Given that these terms are not necessarily synonymous, we examined the important theoretical distinction between the two alternative trajectories or shapes of changes they imply...
  17. ncbi request reprint Biological age and 12-year cognitive change in older adults: findings from the Victoria Longitudinal Study
    Stuart W S MacDonald
    Department of Psychology, University of Victoria, Victoria, B C, Canada
    Gerontology 50:64-81. 2004
    ..Although recent cross-sectional findings indicate that markers of biological age (BA) mediate chronological age (CA) differences in cognitive performance, little is known about their influence on actual cognitive changes...
  18. ncbi request reprint Performance variability is related to change in cognition: evidence from the Victoria Longitudinal Study
    Stuart W S MacDonald
    Department of Psychology, University of Victoria, British Columbia, Canada
    Psychol Aging 18:510-23. 2003
    ..These findings support the view that performance variability serves as a marker of cognitive aging...
  19. pmc IDE (rs6583817) polymorphism and pulse pressure are independently and interactively associated with level and change in executive function in older adults
    G Peggy Mcfall
    Department of Psychology, University of Alberta
    Psychol Aging 29:418-30. 2014
    ..PsycINFO Database Record (c) 2014 APA, all rights reserved). ..
  20. ncbi request reprint Use of memory compensation strategies is related to psychosocial and health indicators
    Cindy M de Frias
    Department of Psychology, University of Victoria, British Columbia, Canada
    J Gerontol B Psychol Sci Soc Sci 58:P12-22. 2003
    ..Linking healthy older adults' cognitive resilience with individual characteristics is an important contribution to emerging conceptions of adaptation and success in late life...
  21. pmc IDE (rs6583817) polymorphism and type 2 diabetes differentially modify executive function in older adults
    G Peggy Mcfall
    Department of Psychology, University of Alberta, Edmonton, Alberta, Canada
    Neurobiol Aging 34:2208-16. 2013
    ..Previously linked to Alzheimer's disease, this IDE variant should be further explored for its potential influence on cognitive phenotypes of normal aging...
  22. ncbi request reprint It's never too late to engage in lifestyle activities: significant concurrent but not change relationships between lifestyle activities and cognitive speed
    Allison A M Bielak
    Department of Psychology, University of Victoria, PO Box 3050 STN CSC, Victoria BC V8W 3P5, Canada
    J Gerontol B Psychol Sci Soc Sci 62:P331-9. 2007
    ..Findings suggest that activity level at one point in time may be a more important predictor of cognition than an individual's changes in activity level...
  23. ncbi request reprint Structure of four executive functioning tests in healthy older adults
    Cindy M de Frias
    Stockholm University and Karolinska Institute, Stockholm, Sweden
    Neuropsychology 20:206-14. 2006
    ..Structural relations showed that poorer executive functioning performance was related to older age and lower fluid intelligence, chi(2)(11, N=418)=23.04, p=.02, RMSEA=.05, CFI=.97, GFI=.98...
  24. pmc Development of isotope labeling LC-MS for human salivary metabolomics and application to profiling metabolome changes associated with mild cognitive impairment
    Jiamin Zheng
    Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada
    Anal Chem 84:10802-11. 2012
    ..Top-ranked 18 metabolites successfully distinguished the two groups, among which seven metabolites were putatively identified while one metabolite, taurine, was definitively identified...
  25. pmc Cognitively elite, cognitively normal, and cognitively impaired aging: neurocognitive status and stability moderate memory performance
    Roger A Dixon
    a Department of Psychology, University of Alberta, Edmonton, AB, Canada
    J Clin Exp Neuropsychol 36:418-30. 2014
    ..We then examined concurrent and two-wave longitudinal performance on composite variables of episodic, semantic, and working memory...
  26. ncbi request reprint Selective adult age differences in an age-invariant multifactor model of declarative memory
    Lars Nyberg
    Department of Psychology, Umea University, Sweden
    Psychol Aging 18:149-60. 2003
    ..Overall, the results support the view that episodic memory is more age sensitive than semantic memory, but they also indicate that aging has differential effects within these 2 forms of memory...
  27. ncbi request reprint Stability and change in adult personality over 6 years: findings from the Victoria Longitudinal Study
    Brent J Small
    Department of Gerontology, University of South Florida, Tampa 33620, USA
    J Gerontol B Psychol Sci Soc Sci 58:P166-76. 2003
    ..Our study of 6-year personality development provided both (a). a confirmation of early significant stability findings and (b). unique evidence for significant individual differences in late adulthood...
  28. ncbi request reprint Latent change models of adult cognition: are changes in processing speed and working memory associated with changes in episodic memory?
    Christopher Hertzog
    School of Psychology, Georgia Institute of Technology, 654 Cherry Street, Atlanta, Georgia 30332 0170, USA
    Psychol Aging 18:755-69. 2003
    ..Dissociations were detected between cross-sectional ability correlations and longitudinal changes. Shuffling the tasks used to define the Working Memory latent variable altered patterns of change correlations...
  29. ncbi request reprint The effect of perceptual distinctiveness on the prospective and retrospective components of prospective memory in young and old adults
    Anna Lisa Cohen
    University of Victoria
    Can J Exp Psychol 57:274-89. 2003
    ..Results are discussed within the context of current theoretical models of prospective memory...
  30. pmc Predicting impending death: inconsistency in speed is a selective and early marker
    Stuart W S MacDonald
    Aging Research Center, Karolinska Institutet, Stockholm, Sweden
    Psychol Aging 23:595-607. 2008
    ..Hierarchical prediction patterns support the view that inconsistency in speed is an early behavioral marker of neurological dysfunction associated with impending death...
  31. ncbi request reprint Interrelations between subjective health and episodic memory change in Swedish and Canadian samples of older adults
    Ake Wahlin
    Stockholm Gerontology Research Center, SE 113 82 Stockholm, Sweden
    Int J Aging Hum Dev 57:21-35. 2003
    ..Thus, the present findings suggest that subjective health may be added to the growing number of individual-difference variables that are predictive of episodic memory change in very old age...
  32. ncbi request reprint Confirmatory factor structure and measurement invariance of the Memory Compensation Questionnaire
    Cindy M de Frias
    Department of Psychology, Stockholm University, Stockholm, Sweden
    Psychol Assess 17:168-78. 2005
    ..Accordingly, the MCQ is available for measuring self-reported efforts to compensate for everyday memory losses...
  33. ncbi request reprint Performance on the Hayling and Brixton tests in older adults: norms and correlates
    Allison A M Bielak
    Department of Psychology, University of Victoria, P O Box 3050 STN CSC, Victoria, BC, Canada V8W 3P5
    Arch Clin Neuropsychol 21:141-9. 2006
    ..Advancing age was associated with poorer performance on both the Hayling and Brixton tests. Results showed that fluid intelligence accounts for some but not all of the age-related variance on these tasks...
  34. ncbi request reprint How do health and biological age influence chronological age and sex differences in cognitive aging: moderating, mediating, or both?
    Ake Wahlin
    Karolinska Institutet, Stockholm Gerontology Research Center, and Department of Psychology, Stockholm University, Stockholm, Sweden
    Psychol Aging 21:318-32. 2006
    ..Overall, both health and BioAge predicted cognitive variation independently of chronological age...