Michael Valenzuela

Summary

Affiliation: University of New South Wales
Country: Australia

Publications

  1. ncbi request reprint Assessment of complex mental activity across the lifespan: development of the Lifetime of Experiences Questionnaire (LEQ)
    Michael J Valenzuela
    School of Psychiatry, University of New South Wales, The Neuropsychiatric Institute, Prince of Wales Hospital, NSW, Australia
    Psychol Med 37:1015-25. 2007
  2. doi request reprint Can cognitive exercise prevent the onset of dementia? Systematic review of randomized clinical trials with longitudinal follow-up
    Michael Valenzuela
    School of Psychiatry, University of New South Wales and Neuropsychiatric Institute, Prince of Wales Hospital, Sydney, NSW, Australia
    Am J Geriatr Psychiatry 17:179-87. 2009
  3. doi request reprint Multiple biological pathways link cognitive lifestyle to protection from dementia
    Michael J Valenzuela
    Regenerative Neuroscience Group, School of Psychiatry, University of New South Wales, Sydney, Australia
    Biol Psychiatry 71:783-91. 2012
  4. ncbi request reprint Magnetic resonance spectroscopy in AD
    M J Valenzuela
    School of Psychiatry, University of New South Wales, and Neuropsychiatric Institute, The Prince Wales Hospital, Randwick, Sydney, Australia
    Neurology 56:592-8. 2001
  5. pmc Lifespan mental activity predicts diminished rate of hippocampal atrophy
    Michael J Valenzuela
    School of Psychiatry, University of New South Wales, Sydney, Australia
    PLoS ONE 3:e2598. 2008
  6. doi request reprint Neural precursors from canine skin: a new direction for testing autologous cell replacement in the brain
    Michael J Valenzuela
    School of Psychiatry, The University of New South Wales, Sydney, Australia
    Stem Cells Dev 17:1087-94. 2008
  7. ncbi request reprint Brain reserve and cognitive decline: a non-parametric systematic review
    Michael J Valenzuela
    School of Psychiatry, University of New South Wales, AustraliaThe Black Dog Institute, Prince of Wales Hospital, Sydney, Australia
    Psychol Med 36:1065-73. 2006
  8. doi request reprint Brain reserve and the prevention of dementia
    Michael J Valenzuela
    School of Psychiatry, University of New South Wales and Neuropsychiatric Institute, The Prince of Wales Hospital, Sydney, Australia
    Curr Opin Psychiatry 21:296-302. 2008
  9. ncbi request reprint Memory training alters hippocampal neurochemistry in healthy elderly
    Michael J Valenzuela
    Neuropsychiatric Institute, The Prince of Wales Hospital, Euroa Centre, Randwick, NSW 2031, Australia
    Neuroreport 14:1333-7. 2003
  10. ncbi request reprint Brain ageing in the new millennium
    J N Trollor
    School of Psychiatry, University of New South Wales and Neuropsychiatric Institute, The Prince of Wales Hospital, Sydney, Australia
    Aust N Z J Psychiatry 35:788-805. 2001

Detail Information

Publications44

  1. ncbi request reprint Assessment of complex mental activity across the lifespan: development of the Lifetime of Experiences Questionnaire (LEQ)
    Michael J Valenzuela
    School of Psychiatry, University of New South Wales, The Neuropsychiatric Institute, Prince of Wales Hospital, NSW, Australia
    Psychol Med 37:1015-25. 2007
    ..Since there is no instrument that comprehensively assesses complex mental activity through the lifespan, we developed and tested the Lifetime of Experiences Questionnaire (LEQ) in a prospective study of healthy ageing...
  2. doi request reprint Can cognitive exercise prevent the onset of dementia? Systematic review of randomized clinical trials with longitudinal follow-up
    Michael Valenzuela
    School of Psychiatry, University of New South Wales and Neuropsychiatric Institute, Prince of Wales Hospital, Sydney, NSW, Australia
    Am J Geriatr Psychiatry 17:179-87. 2009
    ..The aim of this report was to therefore systematically review results from clinical trials, which have examined the effect of cognitive exercise on longitudinal cognitive performance in healthy elderly individuals...
  3. doi request reprint Multiple biological pathways link cognitive lifestyle to protection from dementia
    Michael J Valenzuela
    Regenerative Neuroscience Group, School of Psychiatry, University of New South Wales, Sydney, Australia
    Biol Psychiatry 71:783-91. 2012
    ..Potential mechanisms include disease modification, neuroprotection, and compensation. Prospective, population-based brain series provide the rare opportunity to test the plausibility of these mechanisms in humans...
  4. ncbi request reprint Magnetic resonance spectroscopy in AD
    M J Valenzuela
    School of Psychiatry, University of New South Wales, and Neuropsychiatric Institute, The Prince Wales Hospital, Randwick, Sydney, Australia
    Neurology 56:592-8. 2001
    ..MRS has promise for predicting cognitive status and monitoring pharmacologic efficacy, and can assess cortical and subcortical neurochemical change...
  5. pmc Lifespan mental activity predicts diminished rate of hippocampal atrophy
    Michael J Valenzuela
    School of Psychiatry, University of New South Wales, Sydney, Australia
    PLoS ONE 3:e2598. 2008
    ..Our objective was to determine whether individual differences in lifespan complex mental activity are linked to altered rates of hippocampal atrophy independent of global measures of neurodegeneration...
  6. doi request reprint Neural precursors from canine skin: a new direction for testing autologous cell replacement in the brain
    Michael J Valenzuela
    School of Psychiatry, The University of New South Wales, Sydney, Australia
    Stem Cells Dev 17:1087-94. 2008
    ..This system may be an effective alternative for autologous neurorestorative cell replacement in canine models for further translational research...
  7. ncbi request reprint Brain reserve and cognitive decline: a non-parametric systematic review
    Michael J Valenzuela
    School of Psychiatry, University of New South Wales, AustraliaThe Black Dog Institute, Prince of Wales Hospital, Sydney, Australia
    Psychol Med 36:1065-73. 2006
    ..Our aim was to quantitatively review an independent set of longitudinal studies of cognitive change in order to clarify these factors...
  8. doi request reprint Brain reserve and the prevention of dementia
    Michael J Valenzuela
    School of Psychiatry, University of New South Wales and Neuropsychiatric Institute, The Prince of Wales Hospital, Sydney, Australia
    Curr Opin Psychiatry 21:296-302. 2008
    ..To evaluate and synthesize recent evidence linking mental activity and dementia risk, which commonly invokes 'brain reserve' as the mediating construct...
  9. ncbi request reprint Memory training alters hippocampal neurochemistry in healthy elderly
    Michael J Valenzuela
    Neuropsychiatric Institute, The Prince of Wales Hospital, Euroa Centre, Randwick, NSW 2031, Australia
    Neuroreport 14:1333-7. 2003
    ..Biochemical changes related to cellular energy and cell-membrane turnover were found to increase after structured memory exercises and were limited to the medial temporal lobe...
  10. ncbi request reprint Brain ageing in the new millennium
    J N Trollor
    School of Psychiatry, University of New South Wales and Neuropsychiatric Institute, The Prince of Wales Hospital, Sydney, Australia
    Aust N Z J Psychiatry 35:788-805. 2001
    ..This paper examines the current literature pertaining to brain ageing. The objective of this review is to provide an overview of the effects of ageing on brain structure and function and to examine possible mediators of these changes...
  11. ncbi request reprint Complex mental activity and the aging brain: molecular, cellular and cortical network mechanisms
    Michael J Valenzuela
    School of Psychiatry, University of New South Wales, Sydney, Australia
    Brain Res Rev 56:198-213. 2007
    ..This paper will explore the neurobiological and clinical implications of this framework, in particular in the context of age-related brain disease...
  12. doi request reprint Cognitive lifestyle and long-term risk of dementia and survival after diagnosis in a multicenter population-based cohort
    Michael Valenzuela
    Brain and Ageing Research Program, University of New South Wales, Sydney, New South Wales, Australia
    Am J Epidemiol 173:1004-12. 2011
    ..are necessary for a protective link with dementia incidence. There was little evidence of an effect of cognitive lifestyle on survival after dementia diagnosis...
  13. doi request reprint Cortical responses to a graded working memory challenge predict functional decline in mild cognitive impairment
    Nicole A Kochan
    Brain and Ageing Research Program, School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia
    Biol Psychiatry 70:123-30. 2011
    ..We observed greater deactivation of posteromedial cortex (PMC) under conditions of increased WM load in MCI compared with control subjects. Our objective here is to test whether this paradigm can predict ensuing functional decline...
  14. pmc Impact of load-related neural processes on feature binding in visuospatial working memory
    Nicole A Kochan
    Brain and Ageing Research Program, School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, Australia
    PLoS ONE 6:e23960. 2011
    ..However the neural mechanisms underlying this process, and its modulation by task and load effects, are not well understood...
  15. pmc Cognitive and memory training in adults at risk of dementia: a systematic review
    Nicola J Gates
    School of Psychiatry, University of New South Wales, RandwickNSW 2031, Australia
    BMC Geriatr 11:55. 2011
    ....
  16. ncbi request reprint A novel method for the topographic analysis of neural activity reveals formation and dissolution of 'Dynamic Cell Assemblies'
    Michael Breakspear
    Brain Dynamics Centre, Westmead Hospital, Westmead, NSW, 2145, Australia
    J Comput Neurosci 16:49-68. 2004
    ..In particular, the character of transitions between consecutive synchronous epochs may reflect important aspects of information processing and cognitive flexibility...
  17. pmc Study of Mental Activity and Regular Training (SMART) in at risk individuals: a randomised double blind, sham controlled, longitudinal trial
    Nicola J Gates
    School of Psychiatry, University of New South Wales, and Neuropsychiatric Institute, Prince of Wales Hospital, Randwick NSW 2031, Australia
    BMC Geriatr 11:19. 2011
    ....
  18. ncbi request reprint Magnetic resonance spectroscopy and its applications in psychiatry
    Gin S Malhi
    Mood Disorders Unit, The Villa, Prince of Wales Hospital, Randwick NSW 2031, Sydney, Australia
    Aust N Z J Psychiatry 36:31-43. 2002
    ..This paper briefly describes neuroimaging using magnetic resonance spectroscopy (MRS) and provides a systematic review of its application to psychiatric disorders...
  19. doi request reprint Simulation of neuronal death and network recovery in a computational model of distributed cortical activity
    Mikail Rubinov
    School of Psychiatry, University of New South Wales, Sydney, NSW, Australia
    Am J Geriatr Psychiatry 17:210-7. 2009
    ..The authors utilize a model of activity-dependent neuronal plasticity to study the interplay between synaptogenesis, neuronal death, and neurogenesis on the resulting pattern of neuronal connectivity...
  20. pmc Modeling magnification and anisotropy in the primate foveal confluence
    Mark M Schira
    School of Psychiatry and The Black Dog Institute, University of New South Wales, Sydney Australia
    PLoS Comput Biol 6:e1000651. 2010
    ..Our models demonstrate that the organization follows clear morphogenetic principles that are essential for our understanding of foveal vision in daily life...
  21. ncbi request reprint Screening for bipolar disorder: the utility and comparative properties of the MSS and MDQ measures
    Gordon Parker
    School of Psychiatry, University of New South Wales, Australia
    J Affect Disord 109:83-9. 2008
    ..Our objective was to further determine the diagnostic utility of the Mood Swings Survey (MSS) in distinguishing bipolar and unipolar disorders, and draw comparisons between this measure and the widely-used Mood Disorder Questionnaire (MDQ)...
  22. ncbi request reprint Small-world properties of nonlinear brain activity in schizophrenia
    Mikail Rubinov
    Black Dog Institute and School of Psychiatry, University of New South Wales, Sydney, Australia
    Hum Brain Mapp 30:403-16. 2009
    ..This randomization may underlie the cognitive disturbances characteristic of schizophrenia...
  23. ncbi request reprint The multiscale character of evoked cortical activity
    Michael Breakspear
    The Black Dog Institute, Hospital Rd, Prince of Wales Hospital and The School of Psychiatry, University of New South Wales, Randwick, NSW 2031, Australia
    Neuroimage 30:1230-42. 2006
    ..It also affords a quantitative means of testing hierarchical and multiscale models of cortical activity...
  24. ncbi request reprint The nonlinear theory of schizophrenia
    Michael Breakspear
    The School of Psychiatry, University of New South Wales and the Black Dog Institute, Australia
    Aust N Z J Psychiatry 40:20-35. 2006
    ..Only a few studies of brain activity in schizophrenia, however, have used nonlinear methods. This review paper evaluates the contribution of the nonlinear sciences towards understanding schizophrenia...
  25. ncbi request reprint Spatiotemporal wavelet resampling for functional neuroimaging data
    Michael Breakspear
    Brain Dynamics Centre, Westmead Hospital and University of Sydney, Sydney, Australia
    Hum Brain Mapp 23:1-25. 2004
    ..The limitations and possible extensions of the proposed technique are discussed...
  26. pmc Symbiotic relationship between brain structure and dynamics
    Mikail Rubinov
    Black Dog Institute and School of Psychiatry, University of New South Wales, Sydney, Australia
    BMC Neurosci 10:55. 2009
    ..We provide further biophysical justification for this model and quantitatively characterize the relationship between structure, function and dynamics that accompanies the ensuing self-organization...
  27. ncbi request reprint Synchronous gamma activity: a review and contribution to an integrative neuroscience model of schizophrenia
    Kwang Hyuk Lee
    Cognitive Neuroscience Unit, Department of Psychology, University of Sydney, and The Brain Dynamics Centre, Westmead Hospital, 2145, Sydney, NSW, Australia
    Brain Res Brain Res Rev 41:57-78. 2003
    ..It is concluded that measures of Gamma synchrony offer a valuable window into the core integrative disturbance in schizophrenia cognition...
  28. doi request reprint The foveal confluence in human visual cortex
    Mark M Schira
    School of Psychology, University of New South Wales, Sydney, New South Wales 2052, Australia
    J Neurosci 29:9050-8. 2009
    ..75 degrees, the cortical representations for both V2 and V3 are larger than that of V1, indicating that more neuronal processing power is dedicated to second-level analysis in this small but important part of the visual field...
  29. doi request reprint Multi-frequency phase locking in human somatosensory cortex
    Angela J Langdon
    School of Psychiatry, University of New South Wales, Sydney, Australia
    Prog Biophys Mol Biol 105:58-66. 2011
    ..The existence of n:m phase synchronization demonstrates the contribution of intrinsic cortical dynamics to stimulus encoding and provides a novel phenomenological criteria for the validation of large-scale models of the brain...
  30. doi request reprint The effect of exercise training on cognitive function in older adults with mild cognitive impairment: a meta-analysis of randomized controlled trials
    Nicola Gates
    School of Psychiatry, University of New South Wales, Randwick, Australia Brain and Aging Research Program, Faculty of Medicine, University of New South Wales, Randwick, Australia Electronic address
    Am J Geriatr Psychiatry 21:1086-97. 2013
    ..Our aim was to evaluate efficacy of exercise on cognition in older adults with MCI...
  31. doi request reprint Meta-analysis of plasma amyloid-β levels in Alzheimer's disease
    Fei Song
    Bioanalytical Mass Spectrometry Facility, University of New South Wales, Sydney, Australia
    J Alzheimers Dis 26:365-75. 2011
    ..Baseline Aβ1-40 and Aβ1-42 levels in cognitively normal elderly individuals might be predictors of higher rates of progression to AD, and should be further explored as potential biomarkers...
  32. doi request reprint Cognitive exercise and its role in cognitive function in older adults
    Nicola Gates
    Neuropsychiatric Institute, Prince of Wales Hospital, Randwick, Sydney, NSW 2031, Australia
    Curr Psychiatry Rep 12:20-7. 2010
    ..Finally, practical issues, including the strengths and weaknesses of commercial products, are explored, and recommendations for further research and clinical implementation are made...
  33. pmc Dynamics of a neural system with a multiscale architecture
    Michael Breakspear
    The Black Dog Institute, Prince of Wales Hospital and School of Psychiatry, University of New South Wales, Randwick, NSW 2031, Australia
    Philos Trans R Soc Lond B Biol Sci 360:1051-74. 2005
    ..A framework for relating the dynamical behaviour of the system to measured observables is presented and further extensions to capture wave phenomena and mode coupling are suggested...
  34. pmc Putting brain training to the test in the workplace: a randomized, blinded, multisite, active-controlled trial
    Catherine Borness
    School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia
    PLoS ONE 8:e59982. 2013
    ..Our objective was therefore to investigate the real-world efficacy of CT in the workplace, involving employees from across the working-age spectrum and addressing many of the design issues that have limited trials to date...
  35. pmc Harnessing brain and cognitive reserve for the prevention of dementia
    Michael Valenzuela
    School of Psychiatry, University of New South Wales, Sydney Neuropsychiatric Institute, Prince of Wales Hospital, Randwick, Australia
    Indian J Psychiatry 51:S16-21. 2009
    ..High quality randomized clinical trials are therefore the most urgent priority in this area so that the promise of brain and cognitive reserve can be harnessed for the purpose of the primary prevention of dementia...
  36. pmc Human induced rotation and reorganization of the brain of domestic dogs
    Taryn Roberts
    Faculty of Veterinary Science, University of Sydney, Sydney, New South Wales, Australia
    PLoS ONE 5:e11946. 2010
    ....
  37. ncbi request reprint "Dynamic" connectivity in neural systems: theoretical and empirical considerations
    Michael Breakspear
    School of Physics, University of Sydney, NSW, Australia
    Neuroinformatics 2:205-26. 2004
    ..We conclude by suggesting that techniques based on dynamical interdependence--or "dynamical connectivity"--show significant potential for extracting meaningful information from functional neuroimaging data...
  38. ncbi request reprint Nonlinear phase desynchronization in human electroencephalographic data
    Michael Breakspear
    Brain Dynamics Centre, Department of Psychological Medicine, Westmead Hospital, Darcy Road, Westmead, Sydney, NSW 2048, Australia
    Hum Brain Mapp 15:175-98. 2002
    ..Statistical analysis reveals that this null hypothesis can be robustly rejected in a small number (approximately 4%) of EEG epochs. These findings are discussed with reference to the adaptive function and complex dynamics of the brain...
  39. doi request reprint Inching toward Bethlehem: mapping melancholia
    Gordon Parker
    School of Psychiatry, University of New South Wales, Sydney, Australia
    J Affect Disord 123:291-8. 2010
    ..Analyses then examined the capacity of both the refined symptom and validator sets to discriminate the assigned melancholic and non-melancholic subjects...
  40. ncbi request reprint Homocysteine as a risk factor for cognitive impairment in stroke patients
    Perminder S Sachdev
    School of Psychiatry, University of New South Wales, Prince of Wales Hospital, Sydney, Australia
    Dement Geriatr Cogn Disord 15:155-62. 2003
    ..Elevated total homocysteine (tHcy) levels are associated with an increased risk of cerebrovascular disease. It is uncertain whether tHcy is also an independent risk factor for cognitive impairment...
  41. ncbi request reprint Cognitive correlates of 1H MRS measures in the healthy elderly brain
    Amy J Ross
    School of Psychiatry, University of New South Wales, Sydney, NSW, Australia
    Brain Res Bull 66:9-16. 2005
    ..This research highlights the importance of the relationship between regional brain changes and cognitive function in the ageing brain, and suggests that MRS may be a sensitive marker of subclinical change in cognition...
  42. ncbi request reprint Cognitive leisure activities, but not watching TV, for future brain benefits
    Michael J Valenzuela
    Neurology 67:729; author reply 729. 2006
  43. ncbi request reprint Frequency and clinical, neuropsychological and neuroimaging correlates of apathy following stroke - the Sydney Stroke Study
    Henry Brodaty
    School of Psychiatry, University of New South Wales, Randwick, Australia
    Psychol Med 35:1707-16. 2005
    ..The frequency and clinical, neuropsychological and neuroimaging correlates of apathy in patients who have had a stroke are inadequately defined...
  44. ncbi request reprint Brain reserve and dementia: a systematic review
    Michael J Valenzuela
    The Neuropsychiatric Institute, Prince of Wales Hospital, Sydney, Australia
    Psychol Med 36:441-54. 2006
    ..So far there have been several epidemiological reports but no systematic review to put conflicting results into context. Our aim was to quantitatively review evidence for the effect of brain reserve on incident dementia...