ORCID Profile
0000-0001-7094-9930
Current Organisations
The University of Western Australia Faculty of Science
,
University of Western Australia
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Publisher: Oxford University Press (OUP)
Date: 07-03-2019
Abstract: Despite its brevity and face validity, little is known about the construct validity of the naturalistic “Key Task” of prospective memory (PM), in which an examinee is instructed to remind the examiner at a designated time to retrieve keys (or another belonging) placed out of sight. Study 1 included 162 HIV+ and 52 HIV− comparison participants who completed the Key Task alongside well-validated measures of PM and a comprehensive neuropsychological battery that included everyday functioning measures. Study 2 used broadly parallel methods in 168 older community-dwelling Australians. Overall, the Key Task was not reliably associated with neurocognitive functioning (including clinical and experimental measures of PM), PM symptoms, or everyday functioning in either s le. The Key Task did not demonstrate compelling evidence of construct validity among persons living with HIV disease or older adults, which raises doubts regarding its clinical usefulness as a measure of PM.
Publisher: Springer Science and Business Media LLC
Date: 05-07-2017
DOI: 10.1007/S11065-017-9353-5
Abstract: Several neuropsychological dimensions are correlated with functional outcome (e.g., ability to return to family and community roles) following traumatic brain injury (TBI). Commonly investigated neuropsychological dimensions include verbal memory, visuo-spatial construction, set-shifting, generativity, and processing speed. Unfortunately, small s le sizes across relevant studies have contributed to inconsistent results. Furthermore, no studies have concurrently measured all of the candidate neuropsychological predictors, most of which are known to be inter-correlated. Thus, the unique predictive effects associated with the candidate predictors in TBI recovery have never been investigated. Consequently, this study used both meta-analysis and multiple regression to statistically evaluate neuropsychological candidate predictors across two outcome variables (1) the Glasgow Outcome Scale-Extended (GOS-E) and (2) the Disability Rating Scale (DRS). Seven studies met inclusion criteria. Based on the meta-analyses, the following neuropsychological dimensions were found to be correlated with the GOS-E: immediate verbal memory (r = .43, 95% CI [.27, .58]), delayed verbal memory (r = .43, 95% CI [.21, .61]), visuo-spatial construction (r = .29, 95% CI [.15, .53]), set-shifting (r = -.31, 95% CI [-.45, -.15], and generativity (r = .44, 95% CI [.32, .54]). By contrast, only one neuropsychological dimension was found to be significantly related to the DRS (generativity: r = -.21, 95% CI [-.39, -.01]). Multiple regression on the GOS-E relevant meta-analytically derived correlation matrix determined that all neuropsychological dimensions were significant predictors of the GOS-E (multiple R
Publisher: Wiley
Date: 12-2022
DOI: 10.1002/ALZ.066376
Abstract: Cognitive functioning may be protected against AD pathology via cognitive resilience (conferred by cognitive reserve) or brain resilience (conferred by brain reserve or maintenance). The residual approach to measuring cognitive reserve (i.e., using the residual reserve index) aims to capture cognitive resilience, but may be confounded by unmeasured brain factors representing brain resilience. We sought to distinguish between brain and cognitive resilience by comparing the interactions between the residual reserve index and amyloid, tau, and neurodegeneration (AT(N) Jack et al., 2018) biomarkers when predicting executive function. We hypothesized that the residual reserve index would moderate at least one path from an AT(N) biomarker to executive function (consistent with cognitive resilience), as opposed to moderating a path between two AT(N) biomarkers (suggestive of brain resilience). Participants were 332 older adults from the Alzheimer’s Disease Neuroimaging Initiative (ADNI). AT(N) biomarkers were measured as follows: amyloid = CSF Aβ 42 /Aβ 40 tau = plasma p‐tau181 neurodegeneration = FDG metabolism in AD‐specific regions. AT(N) biomarkers were measured at consecutive time points and entered in a sequential mediation model testing the indirect effects from amyloid to executive function intercept and slope, via tau and/or FDG metabolism. The residual reserve index was entered as a moderator of paths between AT(N) biomarkers, and between AT(N) biomarkers and executive function. The only significant interaction was between the residual reserve index and amyloid when predicting FDG metabolism, such that the indirect effect of amyloid → FDG metabolism → executive function intercept and slope varied as a function of the residual reserve index. With lower amyloid pathology, a higher residual reserve index predicted better executive function via lower FDG metabolism. With higher amyloid pathology, a higher residual reserve index predicted better executive function via higher FDG metabolism. Although the residual reserve index moderated a path between two AT(N) biomarkers, the net effect was consistent with cognitive rather than brain resilience. Our results suggest the residual reserve index captures variation in cognitive reserve specifically, neural efficiency and neural capacity to upregulate metabolism to enhance cognitive resilience in the face of more severe amyloid pathology.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 02-2018
Publisher: Elsevier BV
Date: 10-2018
DOI: 10.1016/J.NEUROBIOLAGING.2018.06.005
Abstract: Cognitive decline is considered an inevitable consequence of aging however, estimates of cognitive aging may be influenced negatively by undetected preclinical Alzheimer's disease (AD). This study aimed to determine the extent to which estimates of cognitive aging were biased by preclinical AD. Cognitively normal older adults (n = 494) with amyloid-β status determined from positron emission tomography neuroimaging underwent serial neuropsychological assessment at 18-month intervals over 72 months. Estimates of the effects of age on verbal memory, working memory, executive function, and processing speed were derived using linear mixed models. The presence of preclinical AD and clinical progression to mild cognitive impairment or dementia during the study were then added to these models as covariates. Initially, age was associated with decline across all 4 cognitive domains. With the effects of elevated amyloid-β and clinical progression controlled, age was no longer associated with decline in verbal or working memory. However, the magnitude of decline was reduced only slightly for executive function and was unchanged for processing speed. Thus, considered together, the results of the study indicate that undetected preclinical AD negatively biases estimates of age-related cognitive decline for verbal and working memory.
Publisher: Springer Science and Business Media LLC
Date: 23-02-2021
DOI: 10.1007/S11065-021-09484-6
Abstract: Alexithymia is the inability to identify and describe one's own emotions. Some research suggests that organic alexithymia may occur after acquired brain injury (ABI). However, the results in the literature are inconsistent, when comparisons are made against healthy controls. Furthermore, a precise estimate of alexithymia prevalence in the ABI population has not yet been reported. Consequently, this meta-analysis aimed to estimate the prevalence and characteristics of alexithymia in ABI, as measured by the Toronto Alexithymia Scale-20 (TAS-20). Based on 22 unique ABI s les, a series of random-effects meta-analyses estimated moderate to large positive effect sizes (i.e., greater alexithymia in ABI s les) for the TAS-20 total scale (Hedges' g = 1.00, 95% CI [0.75, 1.35]), as well as the subscales: difficulty identifying feelings (Hedges' g = 0.92, 95% CI [0.66, 1.17]), difficulty describing feelings (Hedges' g = 0.69, 95% CI [0.50, 0.87]) and externally oriented thinking (Hedges' g = 0.75, 95% CI [0.64, 0.85]). Furthermore, a meta-regression identified a larger effect size (TAS-20 total scale score) for traumatic brain injury (TBI) s les, in comparison to non-TBI s les. Finally, the prevalence of clinically significant levels of alexithymia (TAS-20 total scale ≥ 68.4 i.e., two SDs above the general population mean) in ABI patients was estimated at 15.2%. We interpreted the results to suggest that ABI may have a substantial negative impact on affective processing abilities and, thus, comprehensive assessment of emotional functioning deficits following ABI should be considered by practitioners.
Publisher: Elsevier BV
Date: 11-2019
DOI: 10.1016/J.JAGP.2019.05.008
Abstract: An increasing body of literature suggests a positive, neuroprotective effect for testosterone on cognition in older men. However, randomized clinical trials (RCTs) examining the effects of testosterone supplementation (TS) on cognitive function have been inconclusive. To investigate the potential for TS to prevent cognitive decline in otherwise cognitively healthy older men, by examining the differential effects of TS on cognitively healthy older men in RCTs. Comprehensive search of electronic databases, conference proceedings, and grey literature from 1990 to 2018 was performed to identify RCTs examining the effects of TS on cognition before and after supplementation, in cognitively healthy in iduals. A final s le of 14 eligible RCTs met inclusion criteria. Using pooled random effects expressed as Hedge's g, comparison of placebo versus treatment groups pre- and postsupplementation showed improvements in the treatment group in executive function (g (11) = 0.14, 95% confidence interval [CI]: 0.03-0.26, z = 0.56, p = 0.011). However, it was noted that two studies in our s le did not report a significant increase in mean serum total testosterone (TT) levels in the treatment group after supplementation. Following exclusion of these studies, analysis indicated improvement in the treatment group for the overall cognitive composite (g (11) = 0.18, 95% CI: 0.02-0.33, z = 2.18), psychomotor speed (g (3) = 0.22, 95% CI: 0.01-0.43, z = 2.07) and executive function (g (9) = 0.15, 95% CI: 0.03-0.28, z = 2.35). No significant differences were noted for the global cognition, attention, verbal memory, visuospatial ability or visuospatial memory domains. Overall, our findings support the potential for TS as a preventative measure against cognitive decline, although the effect sizes were small. These findings warrant further observational studies and clinical trials of good methodological quality, to elucidate the effect of TS on cognition.
Publisher: Elsevier BV
Date: 04-2016
Publisher: Springer Science and Business Media LLC
Date: 14-01-2017
DOI: 10.1007/S11065-016-9338-9
Abstract: Successfully assisting older adults to maintain or improve cognitive function, particularly when they are dealing with neurodegenerative disorders such as Alzheimer's disease (AD), remains a major challenge. Cognitive training may stimulate neuroplasticity thereby increasing cognitive and brain reserve. Commercial brain training programs are computerized, readily-available, easy-to-administer and adaptive but often lack supportive data and their clinical validation literature has not been previously reviewed. Therefore, in this review, we report the characteristics of commercially available brain training programs, critically assess the number and quality of studies evaluating the empirical evidence of these programs for promoting brain health in healthy older adults, and discuss underlying causal mechanisms. We searched PubMed, Google Scholar and each program's website for relevant studies reporting the effects of computerized cognitive training on cognitively healthy older adults. The evidence for each program was assessed via the number and quality (PEDro score) of studies, including Randomized Control Trials (RCTs). Programs with clinical studies were subsequently classified as possessing Level I, II or III evidence. Out of 18 identified programs, 7 programs were investigated in 26 studies including follow-ups. Two programs were identified as possessing Level I evidence, three programs demonstrated Level II evidence and an additional two programs demonstrated Level III evidence. Overall, studies showed generally high methodological quality (average PEDro score = 7.05). Although caution must be taken regarding any potential bias due to selective reporting, current evidence supports that at least some commercially available computerized brain training products can assist in promoting healthy brain aging.
Publisher: Informa UK Limited
Date: 20-02-2018
Publisher: American Psychological Association (APA)
Date: 10-2018
DOI: 10.1037/PAS0000565
Abstract: The ability to read irregularly spelled words is commonly used to estimate premorbid intelligence, as this ability has been thought to be resistant to early effects of neurodegenerative disorders. However, studies evaluating decline of this skill in Alzheimer's disease (AD) have produced conflicting results. Irregular word reading was assessed three times over 36 months in a large (N = 995) s le, including healthy control, AD, and Mild Cognitive Impairment (MCI) groups. At baseline, MCI and AD groups read correctly an average of 3.01 and 7.39 fewer words, respectively, than healthy controls. The MCI group's performance remained stable during the study, but the AD group declined. Importantly, the observed decline was likely an underestimate, as significant numbers of the AD participants (42.6%) could not complete the task at follow-up. Use of alternate (e.g., demographics-based) methods is advised to augment or replace word pronunciation in estimating premorbid intelligence in in iduals with even mild AD. (PsycINFO Database Record (c) 2018 APA, all rights reserved).
Publisher: Cambridge University Press (CUP)
Date: 02-10-2019
DOI: 10.1017/S1041610218001072
Abstract: This study investigated the characteristics of subjective memory complaints (SMCs) and their association with current and future cognitive functions. A cohort of 209 community-dwelling in iduals without dementia aged 47–90 years old was recruited for this 3-year study. Participants underwent neuropsychological and clinical assessments annually. Participants were ided into SMCs and non-memory complainers (NMCs) using a single question at baseline and a memory complaints questionnaire following baseline, to evaluate differential patterns of complaints. In addition, comprehensive assessment of memory complaints was undertaken to evaluate whether severity and consistency of complaints differentially predicted cognitive function. SMC and NMC in iduals were significantly different on various features of SMCs. Greater overall severity (but not consistency) of complaints was significantly associated with current and future cognitive functioning. SMC in iduals present distinctive features of memory complaints as compared to NMCs. Further, the severity of complaints was a significant predictor of future cognition. However, SMC did not significantly predict change over time in this s le. These findings warrant further research into the specific features of SMCs that may portend subsequent neuropathological and cognitive changes when screening in iduals at increased future risk of dementia.
Publisher: Oxford University Press (OUP)
Date: 10-08-2020
Abstract: Object location learning and memory may be important for older adults to successfully complete some everyday activities. This cross-sectional, correlational study investigated the ecological relevance of the Location Learning Test-Revised (LLT-R) in 195 community-dwelling, older adults in Western Australia. The LLT-R assesses object location learning and memory for everyday objects over five learning trials and after a 30-min delay. Knowledgeable informants provided structured ratings of participants’ activities of daily living and memory symptoms. A greater number of errors on LLT-R total learning trials were associated with mild problems in activities of daily living (particularly in travel and household domains), but not with memory symptoms. The LLT-R’s association with activities of daily living was accompanied by a small-to-medium effect size and was not better explained by demographics, global cognitive functioning, mood, or chronic medical conditions. Findings provide some support for the ecological relevance of the LLT-R among older community-dwelling adults and suggest that object location learning may play a role in some everyday functioning problems that accompany typical aging.
Publisher: Springer Science and Business Media LLC
Date: 25-10-2017
DOI: 10.1038/S41598-017-14020-9
Abstract: Alzheimer’s Disease (AD) is the most common form of dementia, characterised by extracellular amyloid deposition as plaques and intracellular neurofibrillary tangles of tau protein. As no current clinical test can diagnose in iduals at risk of developing AD, the aim of this project is to evaluate a blood-based biomarker panel to identify in iduals who carry this risk. We analysed the levels of 22 biomarkers in clinically classified healthy controls (HC), mild cognitive impairment (MCI) and Alzheimer’s participants from the well characterised Australian Imaging, Biomarker and Lifestyle (AIBL) study of aging. High levels of IL-10 and IL-12/23p40 were significantly associated with amyloid deposition in HC, suggesting that these two biomarkers might be used to detect at risk in iduals. Additionally, other biomarkers (Eotaxin-3, Leptin, PYY) exhibited altered levels in AD participants possessing the APOE ε4 allele. This suggests that the physiology of some potential biomarkers may be altered in AD due to the APOE ε4 allele, a major risk factor for AD. Taken together, these data highlight several potential biomarkers that can be used in a blood-based panel to allow earlier identification of in iduals at risk of developing AD and/or early stage AD for which current therapies may be more beneficial.
Publisher: Oxford University Press (OUP)
Date: 08-09-2011
Publisher: Informa UK Limited
Date: 05-2003
DOI: 10.1076/JCEN.25.3.431.13800
Abstract: The prevalence of classification accuracy statistics was calculated in five prominent neuropsychology journals and five leading neurology journals for the years 2000 and 2001. Only 29% of neuropsychological articles judged to be appropriate for classification accuracy statistics presented sufficient data to calculate a full range of such analyses. Moreover, classification accuracy statistics were significantly less prevalent in neuropsychology journal articles than in studies published in neurology journals during the same time period. Various indices of sensitivity and/or specificity were present in 31% of neuropsychology articles, whereas fewer than 3% reported predictive values or risk ratios. These findings indicate that classification accuracy statistics, most notably predictive values and risk ratios, are potentially underused in neuropsychology. Investigators and research consumers are encouraged to consider the applicability of classification accuracy statistics as a means of evaluating the clinical relevance of neuropsychological research findings.
Publisher: Bentham Science Publishers Ltd.
Date: 11-05-2016
DOI: 10.2174/1567205013666160315112151
Abstract: Alzheimer's disease (AD) is a degenerative brain disorder and is the most common form of dementia. Minimally invasive approaches are required that combine biomarkers to identify in iduals who are at risk of developing mild cognitive impairment (MCI) and AD, to appropriately target clinical trials for therapeutic discovery as well as lifestyle strategies aimed at prevention. Buccal mucosa cells from the Australian Imaging, Biomarkers and Lifestyle Flagship Study of Ageing cohort (n=60) were investigated for cytological markers that could be used to identify both MCI and AD in iduals. Visual scoring of the buccal cytome demonstrated a significantly lower frequency of basal and karyorrhectic cells in the MCI group compared with controls. A high content, automated assay was developed using laser scanning cytometry to simultaneously measure cell types, nuclear DNA content and aneuploidy, neutral lipid content, putative Tau and amyloid-β (Aβ) in buccal cells. DNA content, aneuploidy, neutral lipids and Tau were similar in all groups. However, there was significantly lower Tau protein in both basal and karyolytic buccal cell types compared with differentiated buccal cells. Aβ, as measured by frequency of cells containing Aβ signal, as well as area and integral of Aβ signal, was significantly higher in the AD group compared with the control group. Buccal cell Aβ was correlated with mini-mental state examination (MMSE) scores (r = -0.436, P=0.001) and several blood-based biomarkers. Combining newly identified biomarkers from buccal cells with those already established may offer a potential route for more specific biomarker panels which may substantially increase the likelihood of better predictive markers for earlier diagnosis of AD.
Publisher: Informa UK Limited
Date: 26-03-2015
Publisher: Springer Science and Business Media LLC
Date: 29-07-2014
DOI: 10.1038/MP.2014.79
Abstract: The aim of this paper was to investigate the association of three well-recognised dietary patterns with cognitive change over a 3-year period. Five hundred and twenty-seven healthy participants from the Australian Imaging, Biomarkers and Lifestyle study of ageing completed the Cancer Council of Victoria food frequency questionnaire at baseline and underwent a comprehensive neuropsychological assessment at baseline, 18 and 36 months follow-up. In idual neuropsychological test scores were used to construct composite scores for six cognitive domains and a global cognitive score. Based on self-reported consumption, scores for three dietary patterns, (1) Australian-style Mediterranean diet (AusMeDi), (2) western diet and (3) prudent diet were generated for each in idual. Linear mixed model analyses were conducted to examine the relationship between diet scores and cognitive change in each cognitive domain and for the global score. Higher baseline adherence to the AusMeDi was associated with better performance in the executive function cognitive domain after 36 months in apolipoprotein E (APOE) ɛ4 allele carriers (P<0.01). Higher baseline western diet adherence was associated with greater cognitive decline after 36 months in the visuospatial cognitive domain in APOE ɛ4 allele non-carriers (P<0.01). All other results were not significant. Our findings in this well-characterised Australian cohort indicate that adherence to a healthy diet is important to reduce risk for cognitive decline, with the converse being true for the western diet. Executive function and visuospatial functioning appear to be particularly susceptible to the influence of diet.
Publisher: Informa UK Limited
Date: 27-06-2018
Publisher: American Psychological Association (APA)
Date: 12-2020
DOI: 10.1037/PAS0000947
Publisher: Informa UK Limited
Date: 07-2012
DOI: 10.1080/13854046.2012.686630
Abstract: Evaluation of resistance to coaching is an important step in the validation of symptom validity tests (SVTs) for clinical use in neuropsychological evaluations. In the present study coaching effects were evaluated for two recently developed SVTs, the Medical Symptom Validity Test (MSVT) and Nonverbal Medical Symptom Validity Test (NVMSVT) as compared with a well-validated existing SVT, the Test of Memory Malingering (TOMM). This study used a simulation design that included 103 healthy younger study volunteers who were randomly assigned into one of four conditions: Symptom Coaching, Test Coaching, Combined Coaching, or Best Effort Control. Specificity for all SVTs was excellent (96-100%). Test Coaching, either alone or combined with Symptom Coaching, was more effective than Symptom Coaching alone in producing raw scores suggestive of "better" effort for all SVTs. However, there were only modest declines in the obtained sensitivity, which remained above 80% for all SVTs. These results provide empirical support for the classification accuracy of the MSVT and NVMSVT, even when challenged with combined coaching interventions. However, further validation using known-groups designs and clinical s les is needed.
Publisher: Springer Science and Business Media LLC
Date: 20-03-2020
Publisher: Frontiers Media SA
Date: 08-05-2017
Publisher: Informa UK Limited
Date: 13-03-2018
DOI: 10.1080/13803395.2018.1444736
Abstract: Apathy is common in older adults and has been linked to adverse health outcomes. The current study examined whether apathy contributes to problems managing activities of daily living (ADLs) and lower quality of life (QoL) in older adults. Participants included 83 community-dwelling older adults. Apathy was assessed using a composite of the self and family-rating scales from the Frontal Systems Behavioral Scale (FrSBe). A knowledgeable informant completed the Activities of Daily Living Questionnaire (ADLQ), and participants completed the World Health Organization Quality of Life (WHOQol) scale. Nominal logistic regressions controlling for age, anxiety and depression symptoms, chronic medical conditions, and global cognition revealed that higher levels of apathy were significantly associated with a wide range of mild ADL problems. In parallel, a multiple linear regression indicated that greater apathy was significantly associated with lower QoL independent of ADL problems, anxious and depressive symptomology, chronic medical conditions, global cognition and age. Findings suggest that apathy confers an increased risk of problems in the independent management of daily activities and poorer well-being among community-dwelling older adults. Neurobehavioral and pharmacological interventions to improve apathy may have beneficial effects on the daily lives of older adults.
Publisher: Springer Science and Business Media LLC
Date: 30-10-2018
DOI: 10.1038/S41398-018-0293-5
Abstract: Accumulating research has linked Mediterranean diet (MeDi) adherence with slower cognitive decline and reduced Alzheimer’s disease (AD) risk. However, no study to-date has examined the relationship between MeDi adherence and accumulation of cerebral Aβ-amyloid (Aβ a pathological hallmark of AD) in older adults. Cognitively normal healthy control participants of the Australian Imaging, Biomarkers and Lifestyle (AIBL) Study of Ageing completed the Cancer Council of Victoria Food Frequency Questionnaire at baseline, which was used to construct a MeDi score for each participant (score range 0–9 higher score indicating higher adherence). Cerebral Aβ load was quantified by Pittsburgh Compound B positron emission tomography at baseline, 18 and 36 months: Only in iduals categorised as “Aβ accumulators”, and thus considered to be on the AD pathway, were included in the analysis ( N = 77). The relationship between MeDi adherence, MeDi components, and change in cerebral Aβ load (baseline to 36 months) was evaluated using Generalised Linear Modelling, accounting for age, gender, education, Apolipoprotein E ε4 allele status, body mass index and total energy intake. Higher MeDi score was associated with less Aβ accumulation in our cohort (β = −0.01 ± 0.004, p = 0.0070). Of the in idual MeDi score components, a high intake of fruit was associated with less accumulation of Aβ (β = −0.04 ± 0.01, p = 0.00036). Our results suggest MeDi adherence is associated with reduced cerebral AD pathology accumulation over time. When our results are considered collectively with previous data linking the MeDi to slower cognitive decline, it is apparent that MeDi adherence warrants further investigation in the quest to delay AD onset.
Publisher: Elsevier BV
Date: 04-2019
DOI: 10.1016/J.BBR.2019.01.013
Abstract: Higher cardiorespiratory fitness has been associated with better cognitive function in older adults yet, this relationship demonstrates a degree of variability across the older adult population. Thus, it is hypothesised that variation in genetic factors may influence the relationship between fitness and cognitive health. One such genetic factor is the brain-derived neurotrophic factor (BDNF) Val66Met polymorphism, which has previously been shown to moderate the relationship between self-reported physical activity and memory performance. In this study we aim to investigate the interaction between BDNF Val66Met polymorphism and objectively-measured cardiorespiratory fitness on performance on tasks assessing verbal and visuospatial memory. Data from ninety-nine cognitively normal men and women aged 60-80 years were used. Fitness was assessed by peak oxygen consumption, and verbal and visuospatial memory were evaluated using well-validated measures. Participants were categorised into: lower-fit Met carriers, higher-fit Met carriers, lower-fit Val/Val, or higher-fit Val/Val. Higher-fit in iduals performed better on a task assessing visuospatial memory, compared with lower-fit in iduals. Furthermore, an interaction between BDNF Val66Met and fitness was observed in terms of visuospatial memory performance on a continuous paired associate learning task whereby lower-fit Met carriers performed 1 standard deviation worse than higher-fit Met carriers. No differences were observed between the higher-fit and lower-fit Val/Val homozygotes. Future intervention studies should evaluate the effect of structured exercise on cognitive health between BDNF Val66Met carriers and Val/Val homozygotes.
Publisher: Elsevier BV
Date: 06-2014
DOI: 10.1016/J.ACTPSY.2014.02.010
Abstract: The current study compared time-based prospective memory (PM) for in iduals with high depressive symptomatology (HDS) and low depressive symptomatology (LDS). We examined PM accuracy rate, clock-checking frequency, and decrements in ongoing task performance (i.e., costs to ongoing tasks) associated with an embedded time-based PM task. HDS participants demonstrated numerically lower but statistically comparable clock-checking frequency to LDS participants. However, their PM performance was significantly poorer than that of LDS participants. The pattern of observed costs to ongoing tasks and correlational analyses between ongoing task performance and PM accuracy showed that, relative to LDS participants, HDS participants were restricted in their allocation of attentional resources to support PM. We concluded that although HDS and LDS participants externally controlled their time-based PM task performance (i.e., clock-checking) similarly, the HDS participants lacked the cognitive initiative to allocate attentional resources to internally control PM task performance. Such internal control might reflect time-estimation processes, the resources required to maintain the PM task response intention, and/or the ability to coordinate the PM task response with ongoing task demands. To our knowledge, this is the first paper to have examined time-based PM strategies used by HDS in iduals beyond clock-checking. The data suggest that interventions that encourage intermittent strategic reviews of PM goals may be beneficial for in iduals with high depressive symptomatology.
Publisher: American Medical Association (AMA)
Date: 12-2015
Publisher: Informa UK Limited
Date: 08-2003
DOI: 10.1076/CLIN.17.3.383.18079
Abstract: There is an emergent need for base rate data on symptom validity tests (SVTs) in clinical populations that are likely to seek disability benefits. The inclusion of HIV under the Americans with Disabilities Act has prompted many persons with HIV-1 infection to apply for disability, which raises the concern that a subset of these in iduals might feign cognitive deficits to obtain benefits. This brief report provides base rate data on one SVT, the Hiscock Digit Memory Test (HDMT), in a s le of 82 non-compensation-seeking, neuropsychologically impaired participants who met diagnostic criteria for an HIV-associated neurocognitive disorder. Approximately 98% of in iduals with HIV-associated neurocognitive disorders performed above an established HDMT cutoff for suboptimal effort (i.e., HDMT> or =90% accuracy), whilst 95% of the s le obtained perfect scores. Clinicians can therefore be confident that, in the absence of severe dementia or amnesia, HDMT scores below standard cutoffs are unlikely to be solely attributable to HIV-associated cognitive impairment.
Publisher: Frontiers Media SA
Date: 03-09-2021
DOI: 10.3389/FNAGI.2021.640381
Abstract: The purpose of this review is to examine human research studies published within the past 6 years which evaluate the role of anthocyanin, flavanol, and flavanone consumption in cognitive function, and to discuss potential mechanisms of action underlying any observed benefits. Evidence to date suggests the consumption of flavonoid-rich foods, such as berries and cocoa, may have the potential to limit, or even reverse, age-related declines in cognition. Over the last 6 years, the flavonoid subgroups of anthocyanins, flavanols, and flavanones have been shown to be beneficial in terms of conferring neuroprotection. The mechanisms by which flavonoids positively modulate cognitive function are yet to be fully elucidated. Postulated mechanisms include both direct actions such as receptor activation, neurotrophin release and intracellular signaling pathway modulation, and indirect actions such as enhancement of cerebral blood flow. Further intervention studies conducted in erse populations with sufficient s le sizes and long durations are required to examine the effect of consumption of flavonoid groups on clinically relevant cognitive outcomes. As populations continue to focus on adopting healthy aging strategies, dietary interventions with flavonoids remains a promising avenue for future research. However, many questions are still to be answered, including identifying appropriate dosage, timeframes for intake, as well as the best form of flavonoids, before definitive conclusions can be drawn about the extent to which their consumption can protect the aging brain.
Publisher: Informa UK Limited
Date: 12-2000
DOI: 10.1076/CHIN.6.4.274.3138
Abstract: This paper discusses the implications of Periventricular Leukomalacia (PVL) lesions for the development of Nonverbal Learning Disabilities (NLD) as illustrated through an identical twin case study. PVL lesions were identified in an 8-year-old child, but were not detected in his identical twin brother who served as a matched comparison. While the nonclinical twin displayed a largely unremarkable neuropsychological profile, the clinical twin evidenced a distinct pattern of social, intellectual, academic, and neuropsychological test results often identified among children with PVL and those with the NLD syndrome. The clinical and theoretical implications for this case study are discussed.
Publisher: Elsevier BV
Date: 02-2021
Publisher: Informa UK Limited
Date: 21-04-2022
Publisher: Informa UK Limited
Date: 13-01-2014
Publisher: SAGE Publications
Date: 21-04-2014
Abstract: The Memory for Intentions Screening Test (MIST) is a clinical measure of prospective memory. There is emerging support for the sensitivity and ecological relevance of the MIST in clinical populations. In the present study, the construct validity of the MIST was evaluated in 40 younger (18-30 years), 24 young-old (60-69 years), and 37 old-old (70+ years) healthy adults. Consistent with expectations derived from the prospective memory and aging literature, older adults demonstrated lower scores on the MIST’s primary scale scores (particularly on the time-based scale), but slightly better performance on the seminaturalistic 24-hour trial. Among the healthy older adults, the MIST showed evidence of both convergent (e.g., verbal fluency) and ergent (e.g., visuoperception) correlations with standard clinical tests, although the magnitude of those correlations were comparable across the time- and event-based scales. Together, these results support the discriminant and convergent validity of the MIST as a measure of prospective memory in healthy older adults.
Publisher: Informa UK Limited
Date: 15-05-2017
DOI: 10.1080/00207454.2016.1182527
Abstract: Purpose/Aim of the study: Poor cardiovascular health, including obesity and altered lipid profiles at mid-life, are linked to increased risk of Alzheimer's disease (AD). The biological mechanisms linking cardiovascular health and cognitive function are unclear though are likely to be multifactorial. This study examined the association between various lipoproteins and cognitive functioning in ageing women. We investigated the relationship between readily available biomarkers (i.e. serum lipoprotein) and cognitive decline in domains associated with increased risk of AD (e.g. episodic verbal memory performance and subjective memory complaint). We report cross-sectional data investigating the relationship between serum total cholesterol, triglycerides, high-density lipoprotein (HDL-C) and low-density lipoprotein with verbal memory and learning ability in 130 women with and without memory complaints (n = 71 and 59, respectively) drawn from a study investigating cognitively healthy Western Australians (average age 62.5 years old). After statistical modelling that controlled for the effects of age, depression and apolipoprotein E genotype, HDL-C was significantly associated with better verbal learning and memory performance, specifically short and long delay-free recalls (F = 3.062 p < .05 and F = 3.2670 p < .05, respectively). Our cross-sectional findings suggest that the positive effect of HDL-C on verbal memory may be present much earlier than previously reported and provide further support for the role of HDL-C in healthy brain ageing. Further exploration of the protective effect of HDL-C on cognitive function in ageing is warranted through follow-up, longitudinal studies.
Publisher: Informa UK Limited
Date: 28-07-2023
DOI: 10.1080/00223891.2022.2095641
Abstract: Alexithymia refers to difficulties identifying feelings (DIF), describing feelings (DDF), and externally orientated thinking (EOT). Originally conceptualized by American psychiatrists, some researchers have since questioned the validity and application of this construct in Asian cultures. However, to date, there is little empirical work formally assessing the invariance of alexithymia across Asian and Western cultures. The present study aimed to help address this gap, by examining the psychometric properties and measurement invariance of two alexithymia measures, the Perth Alexithymia Questionnaire (PAQ) and Toronto Alexithymia Scale-20 (TAS-20), across s les from Singapore (
Publisher: Cambridge University Press (CUP)
Date: 07-03-2013
DOI: 10.1017/S1355617713000180
Abstract: The present study investigated the impact of cue type and delay interval on prospective memory performance in depressed, compared to non-depressed, in iduals using a clinically relevant measure, the Memory for Intentions Screening Test. The depressed group demonstrated impaired performance on time-based, but not event-based, prospective memory tasks relative to the nondepressed group. The depressed group also demonstrated impaired prospective memory on tasks with longer delay intervals (15 min), but not on tasks with shorter delay intervals (2 min). These data support theoretical frameworks that posit that depression is associated with deficits in cognitive initiative (i.e., reduced ability to voluntarily direct attention to relevant tasks) and thus that depressed in iduals are susceptible to poor performance on strategically demanding tasks. The results also raise multiple avenues for developing interventions (e.g., implementation intentions) to improve prospective memory performance among in iduals with depression, with potential implications for medication and other treatment adherence. ( JINS , 2013, 19 , 1–5)
Publisher: Frontiers Media SA
Date: 21-08-2020
Publisher: Human Kinetics
Date: 10-2019
Abstract: Objectives : To examine the associations between physical activity duration and intensity, cardiorespiratory fitness, and executive function in older adults. Methods : Data from 99 cognitively normal adults (age = 69.10 ± 5.1 years n = 54 females) were used in the current study. Physical activity (intensity and duration) was measured with the International Physical Activity Questionnaire, and fitness was measured by analysis of maximal aerobic capacity, VO 2 peak. Executive function was measured comprehensively, including measures of Shifting, Updating, Inhibition, Generativity, and Nonverbal Reasoning. Results : Higher levels of cardiorespiratory fitness were associated with better performance on Generativity ( B = .55 95% confidence interval [.15, .97]). No significant associations were found between self-reported physical activity intensity/duration and executive functions. Discussion : To our knowledge, this study is the first to identify an association between fitness and Generativity. Associations between physical activity duration and intensity and executive function requires further study, using objective physical activity measures and longitudinal observations.
Publisher: Frontiers Media SA
Date: 12-08-2022
DOI: 10.3389/FNAGI.2022.943823
Abstract: The residual approach to measuring cognitive reserve (using the residual reserve index) aims to capture cognitive resilience conferred by cognitive reserve, but may be confounded by factors representing brain resilience. We sought to distinguish between brain and cognitive resilience by comparing interactions between the residual reserve index and amyloid, tau, and neurodegeneration [“AT(N)”] biomarkers when predicting executive function. We hypothesized that the residual reserve index would moderate at least one path from an AT(N) biomarker to executive function (consistent with cognitive resilience), as opposed to moderating a path between two AT(N) biomarkers (suggestive of brain resilience). Participants ( N = 332) were from the Alzheimer’s Disease Neuroimaging Initiative. The residual reserve index represented the difference between observed and predicted memory performance (a positive residual reserve index suggests higher cognitive reserve). AT(N) biomarkers were: CSF β-amyloid 1–42 /β-amyloid 1–40 (A), plasma phosphorylated tau-181 (T), and FDG metabolism in AD-specific regions ([N]). AT(N) biomarkers (measured at consecutive time points) were entered in a sequential mediation model testing the indirect effects from baseline amyloid to executive function intercept (third annual follow-up) and slope (baseline to seventh follow-up), via tau and/or FDG metabolism. The baseline residual reserve index was entered as a moderator of paths between AT(N) biomarkers (e.g., amyloid-tau), and paths between AT(N) biomarkers and executive function. The residual reserve index interacted with amyloid pathology when predicting FDG metabolism: the indirect effect of amyloid → FDG metabolism → executive function intercept and slope varied as a function of the residual reserve index. With lower amyloid pathology, executive function performance was comparable at different levels of the residual reserve index, but a higher residual reserve index was associated with lower FDG metabolism. With higher amyloid pathology, a higher residual reserve index predicted better executive function via higher FDG metabolism. The effect of the residual reserve index on executive function performance via FDG metabolism was consistent with cognitive resilience. This suggests the residual reserve index captures variation in cognitive reserve specifically, neural efficiency, and neural capacity to upregulate metabolism to enhance cognitive resilience in the face of greater amyloid pathology. Implications for future research include the potential bidirectionality between neural efficiency and amyloid accumulation.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 05-2018
Publisher: Informa UK Limited
Date: 10-2003
DOI: 10.1076/JCEN.25.7.979.16481
Abstract: The Test of Memory Malingering (TOMM) has not been adequately validated in a forensic psychiatric setting. Dissimulation of cognitive impairment, as assessed by the TOMM, was evaluated in a group of 25 forensic inpatients admitted for evaluation of Competency to Stand Trial (CST/MSO group), and hypothesized to be at higher risk for feigning cognitive impairment. A comparison group of 36 patients, who were either civilly committed or adjudicated Not Guilty by Reason of Insanity (CIVIL/NGRI group), were hypothesized to be less likely to feign cognitive impairment. Groups were comparable in age, education, premorbid intelligence, and psychiatric symptom severity. Significantly more CST/MSO patients (36%) scored below a recommended TOMM cutoff score relative to CIVIL/NGRI patients (6%). Findings indicate excellent specificity and modest sensitivity, and generally support the validity of the TOMM in a forensic psychiatric population. The utility of different cutoff scores and need for multiple indicators of effort are discussed.
Publisher: SAGE Publications
Date: 05-10-2021
DOI: 10.1177/17470218211048986
Abstract: Research has consistently shown that misinformation can continue to affect inferential reasoning after a correction. This phenomenon is known as the continued influence effect (CIE). Recent studies have demonstrated that CIE susceptibility can be predicted by in idual differences in stable cognitive abilities. Based on this, it was reasoned that CIE susceptibility ought to have some degree of stability itself however, this has never been tested. The current study aimed to investigate the temporal stability of retraction sensitivity, arguably a major determinant of CIE susceptibility. Participants were given parallel forms of a standard CIE task 4 weeks apart, and the association between testing points was assessed with an intra-class correlation coefficient and confirmatory factor analysis. Results suggested that retraction sensitivity is relatively stable and can be predicted as an in idual-differences variable. These results encourage continued in idual-differences research on the CIE and have implications for real-world CIE intervention.
Publisher: Springer Science and Business Media LLC
Date: 26-04-2021
Publisher: Springer Science and Business Media LLC
Date: 23-03-2021
DOI: 10.1007/S11065-021-09501-8
Abstract: Apathy and depression are common sequelae of acquired brain injury (ABI). Apathy is a syndrome characterized by diminished motivation and purposeful behaviours. Depression is a mood disorder featuring sadness, worthlessness, anhedonia and suicidal ideation. Both are associated negatively with activities of daily living (ADL), the skills required to fulfil basic and complex physical needs. However, the current literature's results are inconsistent and based on relatively small s le sizes. Furthermore, the unique and combined effects of apathy and depression as predictors of ADL have not yet been estimated. This is important, as both may have implications for planning rehabilitation after an ABI. Consequently, we aimed to estimate the association between apathy, depression and ADL in the stroke and traumatic brain injured population via meta-analysis and meta-analytic path-analysis. Based on the meta-analyses (N = 1,166 to N = 1,389), we estimated the following statistically significant bivariate effects: depression and apathy (r = .53, 95% CI: .42/.63), depression and ADL (r = -.27, 95% CI: -.43/-.11), apathy and ADL (r = -.41, 95% CI: -.51/-.31). A meta-analytic mediation model found that depression had a significant indirect effect onto ADL (β = -.17, 95% CI: -.26/-.09), while apathy had a significant direct effect (β = -.34, 95% CI: -.48/-.19) onto ADL (model R
Publisher: Elsevier BV
Date: 05-2016
DOI: 10.1016/J.NEUBIOREV.2016.01.004
Abstract: Traumatic brain injury (TBI) increases the risk of neurodegenerative disorders many years post-injury. However, molecular mechanisms underlying the relationship between TBI and neurodegenerative diseases, such as Alzheimer's disease (AD), remain to be elucidated. Nevertheless, previous studies have demonstrated a link between TBI and increased amyloid-β (Aβ), a protein involved in AD pathogenesis. Here, we review animal studies that measured Aβ levels following TBI. In addition, from a pool of initially identified 1209 published papers, we examined data from 19 eligible animal model studies using a meta-analytic approach. We found an acute increase in cerebral Aβ levels ranging from 24h to one month following TBI (overall log OR=2.97 ± 0.40, p<0.001). These findings may contribute to further understanding the relationship between TBI and future dementia risk. The methodological inconsistencies of the studies discussed in this review suggest the need for improved and more standardised data collection and study design, in order to properly elucidate the role of TBI in the expression and accumulation of Aβ.
Publisher: Elsevier BV
Date: 04-2022
DOI: 10.1016/J.JAD.2022.01.091
Abstract: Alexithymia is a multidimensional personality trait comprised of difficulty identifying feelings, difficulty describing feelings, and externally orientated thinking. The assessment of alexithymia in people with acquired brain injury (ABI) is of clinical interest because alexithymia is linked to poor psychosocial functioning and community reintegration after ABI. To date, alexithymia measures have not been psychometrically investigated/validated in an ABI s le, restricting confident empirical work in this area. We aimed to fill this gap by assessing the psychometric properties of the Perth Alexithymia Questionnaire (PAQ) in adults with ABI and determining whether the alexithymia construct manifests similarly in ABI s les compared to the general community. The PAQ and Depression Anxiety Stress Scales-21 were administered to an ABI s le (N = 350) and a community s le (N = 1012). Factor structure, measurement invariance, internal consistency reliability, and concurrent/discriminant validity were explored. Our confirmatory factor analysis of the PAQ supported the intended five-factor correlated model as the best solution, where items loaded well onto the five intended subscales. This factor structure was invariant across ABI and community s les. Good reliability and concurrent and discriminant validity were also established. The PAQ is a self-report measure and may be impacted by insight deficits known to occur after ABI. Our data suggests that the PAQ has good validity and reliability as a measure of alexithymia. The latent structure of alexithymia manifests similarly in ABI and community s les. This study provides the first psychometric foundation for confident assessment of alexithymia in ABI.
Publisher: Oxford University Press (OUP)
Date: 10-2019
Abstract: To prospectively examine 8-year risk of clinical disease progression to mild cognitive impairment (MCI)/dementia in older adults ≥60 with superior episodic memory (SuperAgers) compared to those cognitively normal for their age (CNFA). Additionally, to determine the extent to which SuperAgers were resilient to the negative effects of elevated amyloid-beta (Aβ+) on cognition. Participants were classified as SuperAgers based on episodic memory performance consistent with younger adults aged 30–44 and no impairment on non-memory tests (n = 179), and were matched with CNFA on age, sex, education, and follow-up time (n = 179). Subdistribution hazard models examined risk of clinical progression to MCI/dementia. Linear mixed models assessed the effect of Aβ on cognition over time. Prevalence of Aβ+ and APOE ε4 was equivalent between SuperAgers and CNFA. SuperAgers had 69%–73% reduced risk of clinical progression to MCI/dementia compared to CNFA (HR: 0.27–0.31, 95% CI: 0.11–0.73, p & .001). Aβ+ was associated with cognitive decline in verbal memory and executive function, regardless of SuperAger/CNFA classification. In the absence of Aβ+, equivalent age-related changes in cognition were observed between SuperAgers and CNFA. SuperAgers displayed resilience against clinical progression to MCI/dementia compared to CNFA despite equivalent risk for Alzheimer’s disease (AD) however, SuperAgers had no greater protection from Aβ+ than CNFA. The deleterious effects of Aβ on cognition persist regardless of baseline cognitive ability. Thus, superior cognitive performance does not reflect resistance against the neuropathological processes associated with AD, and the observed resilience for SuperAgers may instead reflect neuropsychological criteria for cognitive impairment.
Publisher: Oxford University Press (OUP)
Date: 05-2016
DOI: 10.5665/SLEEP.5756
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 11-2016
Publisher: Wiley
Date: 19-10-2017
Publisher: Cambridge University Press (CUP)
Date: 18-07-2013
DOI: 10.1017/S1041610213001087
Abstract: To date evidence of the relationship between cognition and Aβ amyloid during the early stages of Alzheimer's Disease (AD) has been inconsistent. This study aimed to describe the nature and magnitude of the relationship between Aβ amyloid and cognitive performance of in iduals without dementia. Composite cognitive measures were developed from the Australian Imaging Biomarkers and Lifestyle study neuropsychological test battery using data from 768 healthy older adults and 133 adults with mild cognitive impairment (MCI). A subgroup of this s le (174 healthy, 53 MCI) underwent neuroimaging for Aβ amyloid. Within the MCI group in iduals with high Aβ amyloid showed selective impairment for memory compared with those with low Aβ amyloid however, this difference was not evident in the healthy group. The current findings provide further evidence of the relationship between Aβ amyloid and cognition, with memory impairment being the primary symptom of the underlying disease during the prodromal phases of AD.
Publisher: INPLASY - International Platform of Registered Systematic Review and Meta-analysis Protocols
Date: 25-11-2022
DOI: 10.37766/INPLASY2022.11.0125
Abstract: Review question / Objective: This review aims to determine the prevalence and characteristics of empathic functioning in adults with an acquired brain injury (ABI). Specifically, the review will aim to answer the following questions: 1. What is the prevalence of empathy deficits after ABI? 2. To what extent does self-reported total, cognitive and affective empathy differ between participants with ABI and neurotypical controls? 3. Are there any gender differences in self-reported empathic functioning after ABI? Information sources: Ovid MEDLINE, ProQuest, PsycINFO, Scopus, and Web of Science. Additional studies may be identified by hand-searching, included scanning the reference list of included studies. Unpublished studies will be sought.
Publisher: Informa UK Limited
Date: 26-12-2019
DOI: 10.1080/09602011.2019.1704421
Abstract: Pronounced difficulties in functional outcomes often follow acquired brain injury (ABI), and may be due, in part, to deficits in metacognitive knowledge (being unaware of one's cognitive strengths and limitations). A meta-analytic review of the literature investigating the relationship between metacognitive knowledge and functional outcomes in ABI is timely, particularly given the presence of apparently inconsistent findings. Twenty-two articles revealed two distinct methods of measuring metacognitive knowledge: (1)
Publisher: American Psychological Association (APA)
Date: 10-2021
DOI: 10.1037/NEU0000746
Publisher: Cambridge University Press (CUP)
Date: 14-01-2013
DOI: 10.1017/S1355617712001361
Abstract: Deficits in prospective memory (PM i.e., enacting previously learned actions at the right occasion) and risky decision-making (i.e., making choices with a high chance of undesirable/dangerous outcomes) are both common among in iduals with substance use disorders (SUD). Previous research has raised the possibility of a specific relationship between PM and risk-taking, and the present study aimed to systematically study if PM provides unique variance in the prediction of risky decision-making. Two s les were included: (1) a group of 45 in iduals with SUD currently in treatment, and (2) a nonclinical group of 59 university students with high-risk drinking and/or substance use. Regression analyses indicated that time-based, but not event-based, PM predicted increased risky behavior (e.g., risky sexual practices and criminal behaviors) in both groups after controlling for demographic, psychiatric, and substance use variables, as well as other neuropsychological functions. The current findings contribute to the growing literature supporting the role of PM as a predictor of everyday functioning, and suggest that cognitive rehabilitation may be an important avenue of research as an adjunct to traditional substance use treatment, particularly in addressing the potential adverse effects of PM deficits in the implementation of treatment-related homework activities and risk management strategies. ( JINS , 2013, 19 , 1–11)
Publisher: Elsevier BV
Date: 05-2021
Publisher: Oxford University Press (OUP)
Date: 24-07-2022
Abstract: The Western Australia Olfactory Memory Test (WAOMT) is a newly developed test designed to meet a need for a comprehensive measure of olfactory episodic memory (OEM) for clinical and research applications. This study aimed to establish the psychometric properties of the WAOMT in a s le of 209 community-dwelling older adults. An independent s le of 27 test-naïve participants were recruited to assess test retest reliability (between 7 and 28 days). Scale psychometric properties were examined using item response theory methods, combined s les (final N = 241). Convergent validity was assessed by comparing performance on the WAOMT with a comprehensive neuropsychological battery of domains (verbal and visual episodic memory, and odor identification), as well as other neuropsychological skills. Based on previous literature, it was predicted that the WAOMT would be positively correlated with conceptually similar cognitive domains. The WAOMT is a psychometrically sound test with adequate reliability properties and demonstrated convergent validity with tests of verbal and episodic memory and smell identification. Patterns of performance highlight learning and memory characteristics unique to OEM (e.g., learning curves, cued and free recall). Clinical and research implications include streamlining future versions of the WAOMT to ease patient and administrative burden, and the potential to reliably detect early neuropathological changes in healthy older adults with nonimpaired OEM abilities.
Publisher: Oxford University Press (OUP)
Date: 04-01-2019
Abstract: Provide updated older adult (ages 60+) normative data for the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), Form A, using regression techniques, and corrected for education, age, and gender. Participants (aged 60–93 years N = 415) were recruited through the Healthy Ageing Research Program (HARP), University of Western Australia, and completed Form A of the RBANS as part of a wider neuropsychological test battery. Regression-based techniques were used to generate normative data rather than means-based methods. This methodology allows for the control of demographic variables using continuous data. To develop norms, the data were assessed for: (1) normality (2) associations between each subtest score and age, education, and gender (3) the effect of age, education, and gender on subtest scores and (4) residual scores which were converted to percentile distributions. Differences were noted between the three s les, some of which were small and may not represent a clinically meaningful difference. Younger age, more years of education, and female gender were associated with better scores on most subtests. Frequency distributions, means, and standard deviations were produced using unstandardized residual scores to remove the effects of age, education, and gender. These normative data expand upon past work by using regression-based techniques to generate norms, presenting percentiles, as well as means and standard deviations, correcting for the effect of gender, and providing a free-to-use Excel macro to calculate percentiles.
Publisher: Springer Science and Business Media LLC
Date: 27-04-2020
Publisher: Springer Science and Business Media LLC
Date: 28-08-2015
DOI: 10.1038/EYE.2015.157
Publisher: Cambridge University Press (CUP)
Date: 15-12-2021
DOI: 10.1017/S1355617720001186
Abstract: Sleep quantity and quality are associated with executive function (EF) in experimental studies, and in in iduals with sleep disorders. With advancing age, sleep quantity and quality decline, as does the ability to perform EF tasks, suggesting that sleep disruption may contribute to age-related EF declines. This cross-sectional cohort study tested the hypothesis that poorer sleep quality (i.e., the frequency and duration of awakenings) and/or quantity may partly account for age-related EF deficits. Community-dwelling older adults ( N = 184) completed actigraphic sleep monitoring then a range of EF tasks. Two EF factors were extracted using exploratory structural equation modeling. Sleep variables did not mediate the relationship between age and EF factors. Post hoc moderated mediation analyses were conducted to test whether cognitive reserve compensates for sleep-related EF deficits, using years of education as a proxy measure of cognitive reserve. We found a significant interaction between cognitive reserve and the number and frequency of awakenings, explaining a small (approximately 3%), but significant amount of variance in EF. Specifically, in in iduals with fewer than 11 years of education, greater sleep disturbance was associated with poorer EF, but sleep did not impact EF in those with more education. There was no association between age and sleep quantity. This study highlights the role of cognitive reserve in the sleep–EF relationship, suggesting in iduals with greater cognitive reserve may be able to counter the impact of disturbed sleep on EF. Therefore, improving sleep may confer some protection against EF deficits in vulnerable older adults.
Publisher: Cambridge University Press (CUP)
Date: 28-10-2011
DOI: 10.1017/S1355617711001263
Abstract: Moderate declines in prospective memory (PM) are common among older adults, but whether such decrements are associated with everyday functioning problems is not well established. To examine this issue, we administered the Memory for Intentions Screening Test (MIST), Prospective and Retrospective Memory Questionnaire (PRMQ), and Activities of Daily Living Questionnaire (ADLQ) to 50 healthy older Australian adults as part of a broader neuropsychological battery. In a series of hierarchical regressions controlling for demographics, medical sychiatric factors, and other neurocognitive functions, the MIST event-based PM score and PRMQ PM scale were significantly associated with the total number of instrumental ADL (IADL) domains in which participants reported needing assistance. Extending prior findings in clinical populations, results indicate that lower PM functioning is uniquely associated with mild, concurrent IADL problems in healthy older adults. Future investigation of the potentially moderating effects of cognitive and behavioral compensatory strategies may be beneficial. ( JINS , 2012, 18 , 134–138)
Publisher: Wiley
Date: 13-12-2019
Publisher: Elsevier BV
Date: 04-2016
DOI: 10.1016/J.OPHTHA.2015.11.009
Abstract: To derive macular thickness measures and their associations by performing rapid, automated segmentation of spectral-domain optical coherence tomography (SD OCT) images collected and stored as part of the UK Biobank (UKBB) study. Large, multisite cohort study in the United Kingdom. Analysis of cross-sectional data. Adults from the United Kingdom aged 40 to 69 years. Participants had nonmydriatic SD OCT (Topcon 3D OCT-1000 Mark II Topcon GB, Newberry, Berkshire, UK) performed as part of the ocular assessment module. Rapid, remote, automated segmentation of the images was performed using custom optical coherence tomography (OCT) image analysis software (Topcon Advanced Boundary Segmentation [TABS] Topcon GB) to generate macular thickness values. We excluded people with a history of ocular or systemic disease (diabetes or neurodegenerative diseases) and eyes with reduced vision (<0.1 logarithm of the minimum angle of resolution) or with low SD OCT signal-to-noise ratio and low segmentation success certainty. Macular thickness values across 9 Early Treatment of Diabetic Retinopathy Study (ETDRS) subfields. The SD OCT scans of 67 321 subjects were available for analysis, with 32 062 people with at least 1 eye meeting the inclusion criteria. There were 17 274 women and 14 788 men, with a mean (standard deviation [SD]) age of 55.2 (8.2) years. The mean (SD) logarithm of the minimum angle of resolution visual acuity was -0.075 (0.087), and the refractive error was -0.071 (+1.91) diopters (D). The mean (SD) central macular thickness (CMT) in the central 1-mm ETDRS subfield was 264.5 (22.9) μm, with 95% confidence limits of 220.8 and 311.5 μm. After adjusting for covariates, CMT was positively correlated with older age, female gender, greater myopia, smoking, body mass index (BMI), and white ethnicity (all P < 0.001). Of note, macular thickness in other subfields was negatively correlated with older age and greater myopia. We report macular thickness data derived from SD OCT images collected as part of the UKBB study and found novel associations among older age, ethnicity, BMI, smoking, and macular thickness.
Publisher: Cambridge University Press (CUP)
Date: 30-08-2022
DOI: 10.1017/S1355617722000546
Abstract: Brain reserve, cognitive reserve, and education are thought to protect against late-life cognitive decline, but these variables have not been directly compared to one another in the same model, using future cognitive and functional decline as outcomes. We sought to determine whether the influence of these protective factors on executive function (EF) and daily function decline was dependent upon Alzheimer’s disease (AD) pathology severity, as measured by the total tau to beta-amyloid (T-τ/Aβ 1-42 ) ratio in cerebrospinal fluid (CSF). Participants were 1201 older adult volunteers in the Alzheimer’s Disease Neuroimaging Initiative (ADNI) study. Brain reserve was defined using a composite index of structural brain volumes (total brain matter, hippoc us, and white matter hyperintensity). Cognitive reserve was defined as the variance in episodic memory performance not explained by brain integrity and demographics. At higher levels of T-τ/Aβ 1-42 , brain and cognitive reserve predicted slower decline in EF. Only brain reserve attenuated decline at lower levels of T-τ/Aβ 1-42 . Education had no independent association with cognitive decline. These results point to a hierarchy of protection against aging- and disease-associated cognitive decline. When pathology is low, only structural brain integrity predicts rate of future EF decline. The ability of cognitive reserve to predict future EF decline becomes stronger as CSF biomarker evidence of AD increases. Although education is typically thought of as a proxy for cognitive reserve, it did not show any protective effects on cognition after accounting for brain integrity and the residual cognitive reserve index.
Publisher: Informa UK Limited
Date: 02-2011
Publisher: Informa UK Limited
Date: 21-05-2014
DOI: 10.1080/13803395.2014.918090
Abstract: Depression has been found to be related to neurocognitive deficits in areas important to successful prospective memory (PM) performance, including executive function, attention, and retrospective memory. However, research specific to depression and PM has produced a mixed pattern of results. The current study further examined the task conditions in which event-based PM deficits may emerge in in iduals with high depressive symptomatology (HDS) relative to in iduals with low depressive symptomatology (LDS) and the capacity of HDS in iduals to allocate attentional resources to event-based PM tasks. Sixty-four participants (32 HDS, 32 LDS) were required to make a PM response when target words were presented during an ongoing lexical decision task. When the importance of the ongoing task was emphasized, response time costs to the ongoing task, and PM accuracy, did not differ between the HDS and LDS groups. This finding is consistent with previous research demonstrating that event-based PM task accuracy is not always impaired by depression, even when the PM task is resource demanding. When the importance of the PM task was emphasized, costs to the ongoing task further increased for both groups, indicating an increased allocation of attentional resources to the PM task. Crucially, while a corresponding improvement in PM accuracy was observed in the LDS group when the importance of the PM task was emphasized, this was not true for the HDS group. The lack of improved PM accuracy in the HDS group compared with the LDS group despite evidence of increased cognitive resources allocated to PM tasks may have been due to inefficiency in the application of the allocated attention, a dimension likely related to executive function difficulties in depression. Qualitatively different resource allocation patterns may underlie PM monitoring in HDS versus LDS in iduals.
Publisher: Oxford University Press (OUP)
Date: 08-07-2020
Abstract: Older adults experience hallucinations in a variety of social, physical, and mental health contexts. Not everyone is open about these experiences, as hallucinations are surrounded with stigma. Hence, hallucinatory experiences in older in iduals are often under-recognized. They are also commonly misunderstood by service providers, suggesting that there is significant scope for improvement in the training and practice of professionals working with this age group. The aim of the present article is to increase knowledge about hallucinations in older adults and provide a practical resource for the health and aged-care workforce. Specifically, we provide a concise narrative review and critique of (1) workforce competency and training issues, (2) assessment tools, and (3) current treatments and management guidelines. We conclude with a brief summary including suggestions for service and training providers and future research.
Publisher: Frontiers Media SA
Date: 18-02-2015
Publisher: Informa UK Limited
Date: 11-05-2023
Publisher: American Psychiatric Association Publishing
Date: 04-2005
Publisher: Springer Science and Business Media LLC
Date: 26-02-2018
DOI: 10.1038/S41398-018-0094-X
Abstract: The glymphatic system is postulated to be a mechanism of brain Aβ-amyloid clearance and to be most effective during sleep. Ablation of the astrocytic end-feet expressed water-channel protein, Aquaporin-4, in mice, results in impairment of this clearance mechanism and increased brain Aβ-amyloid deposition, suggesting that Aquaporin-4 plays a pivotal role in glymphatic function. Currently there is a paucity of literature regarding the impact of AQP4 genetic variation on sleep, brain Aβ-amyloid burden and their relationship to each other in humans. To address this a cross-sectional observational study was undertaken in cognitively normal older adults from the Australian Imaging, Biomarkers and Lifestyle (AIBL) study. Genetic variants in AQP4 were investigated with respect to self-reported Pittsburgh Sleep Quality Index sleep parameters, positron emission tomography derived brain Aβ-amyloid burden and whether these genetic variants moderated the sleep-Aβ-amyloid burden relationship. One AQP4 variant, rs72878776, was associated with poorer overall sleep quality, while several SNPs moderated the effect of sleep latency (rs491148, rs9951307, rs7135406, rs3875089, rs151246) and duration (rs72878776, rs491148 and rs2339214) on brain Aβ-amyloid burden. This study suggests that AQP4 genetic variation moderates the relationship between sleep and brain Aβ-amyloid burden, which adds weight to the proposed glymphatic system being a potential Aβ-amyloid clearance mechanism and suggests that AQP4 genetic variation may impair this function. Further, AQP4 genetic variation should be considered when interpreting sleep-Aβ relationships.
Publisher: Elsevier BV
Date: 04-2011
Publisher: Cambridge University Press (CUP)
Date: 10-2014
DOI: 10.1017/S135561771400085X
Abstract: Bigler (2012) and Larrabee (2012) recently addressed the state of the science surrounding performance validity tests (PVTs) in a dialogue highlighting evidence for the valid and increased use of PVTs, but also for unresolved problems. Specifically, Bigler criticized the lack of guidance from neurocognitive processing theory in the PVT literature. For ex le, in idual PVTs have applied the simultaneous forced-choice methodology using a variety of test characteristics (e.g., word vs . picture stimuli) with known neurocognitive processing implications (e.g., the “picture superiority effect”). However, the influence of such variations on classification accuracy has been inadequately evaluated, particularly among cognitively impaired in iduals. The current review places the PVT literature in the context of neurocognitive processing theory, and identifies potential methodological factors to account for the significant variability we identified in classification accuracy across current PVTs. We subsequently evaluated the utility of a well-known cognitive manipulation to provide a Clinical Analogue Methodology (CAM), that is, to alter the PVT performance of healthy in iduals to be similar to that of a cognitively impaired group. Initial support was found, suggesting the CAM may be useful alongside other approaches (analogue malingering methodology) for the systematic evaluation of PVTs, particularly the influence of specific neurocognitive processing components on performance. ( JINS , 2014, 20 , 873–886)
Publisher: Informa UK Limited
Date: 05-09-2008
Publisher: Cambridge University Press (CUP)
Date: 22-09-2022
DOI: 10.1017/S1355617721001132
Abstract: Exercise has been found to be important in maintaining neurocognitive health. However, the effect of exercise intensity level remains relatively underexplored. Thus, to test the hypothesis that self-paced high-intensity exercise and cardiorespiratory fitness (peak aerobic capacity VO 2peak ) increase grey matter (GM) volume, we examined the effect of a 6-month exercise intervention on frontal lobe GM regions that support the executive functions in older adults. Ninety-eight cognitively normal participants (age = 69.06 ± 5.2 years n = 54 female) were randomised into either a self-paced high- or moderate-intensity cycle-based exercise intervention group, or a no-intervention control group. Participants underwent magnetic resonance imaging and fitness assessment pre-intervention, immediately post-intervention, and 12-months post-intervention. The intervention was found to increase fitness in the exercise groups, as compared with the control group ( F = 9.88, p = .001). Changes in pre-to-post-intervention fitness were associated with increased volume in the right frontal lobe ( β = 0.29, p = 0.036, r = 0.27), right supplementary motor area ( β = 0.30, p = 0.031, r = 0.29), and both right ( β = 0.32, p = 0.034, r = 0.30) and left gyrus rectus ( β = 0.30, p = 0.037, r = 0.29) for intervention, but not control participants. No differences in volume were observed across groups. At an aggregate level, six months of self-paced high- or moderate-intensity exercise did not increase frontal GM volume. However, experimentally-induced changes in in idual cardiorespiratory fitness was positively associated with frontal GM volume in our s le of older adults. These results provide evidence of in idual variability in exercise-induced fitness on brain structure.
Publisher: Elsevier BV
Date: 04-2020
DOI: 10.1016/J.NEUROBIOLAGING.2019.12.022
Abstract: Cognitive reserve has been described as offering protection against Alzheimer's disease (AD) and other neurodegenerative conditions, but also against age-associated brain changes. Using data from the Alzheimer's Disease Neuroimaging Initiative, we defined cognitive reserve using the residual reserve index: episodic memory performance residualized for 3T MRI-derived brain volumes and demographics. We examined whether cognitive reserve predicted executive function (EF) decline equally across 2 groups of older adults-AD biomarker-positive (n = 468) and -negative (n = 402)-defined by the tau-to-amyloid ratio in cerebrospinal fluid. A significant interaction between the residual reserve index and biomarker group revealed that the effect of cognitive reserve on EF decline was dependent on pathology status. In the biomarker-positive group, higher cognitive reserve predicted EF decline over five years. However, cognitive reserve did not predict EF decline in the biomarker-negative group. These results suggest a certain level of AD pathology may be needed before cognitive reserve exerts its protective effects on future cognition however, further research that tracks cognitive reserve longitudinally is needed.
Publisher: Informa UK Limited
Date: 15-11-2020
Publisher: Informa UK Limited
Date: 03-11-2011
Publisher: Elsevier BV
Date: 07-2007
Publisher: Wiley
Date: 07-2014
Publisher: Wiley
Date: 11-05-2019
Publisher: Elsevier BV
Date: 10-2018
Publisher: Informa UK Limited
Date: 06-02-2023
Publisher: Wiley
Date: 12-08-2019
Publisher: Informa UK Limited
Date: 30-08-2019
DOI: 10.1080/13825585.2018.1513449
Abstract: The high prevalence of sleep disruption among older adults may have implications for cognitive aging, particularly for higher-order aspects of cognition. One domain where sleep disruption may contribute to age-related deficits is prospective memory-the ability to remember to perform deferred actions at the appropriate time in the future. Community-dwelling older adults (55-93 years, N = 133) undertook assessment of sleep using actigraphy and participated in a laboratory-based prospective memory task. After controlling for education, sleep disruption (longer awakenings) was associated with poorer prospective memory. Additionally, longer awakenings mediated the relationship between older age and poorer prospective memory. Other metrics of sleep disruption, including sleep efficiency and wake after sleep onset, were not related to prospective memory, suggesting that examining the features of in idual wake episodes rather than total wake time may help clarify relationships between sleep and cognition. The mediating role of awakening length was partially a function of greater depression and poorer executive function (shifting) but not retrospective memory. This study is among the first to examine the association between objectively measured sleep and prospective memory in older adults. Furthermore, this study is novel in suggesting sleep disruption might contribute to age-related prospective memory deficits perhaps, with implications for cognitive aging more broadly. Our results suggest that there may be opportunities to prevent prospective memory decline by treating sleep problems.
Publisher: Public Library of Science (PLoS)
Date: 05-04-2023
DOI: 10.1371/JOURNAL.PONE.0283951
Abstract: Misinformation can continue to influence reasoning after correction this is known as the continued influence effect (CIE). Theoretical accounts of the CIE suggest failure of two cognitive processes to be causal, namely memory updating and suppression of misinformation reliance. Both processes can also be conceptualised as subcomponents of contemporary executive function (EF) models specifically, working-memory updating and prepotent-response inhibition. EF may thus predict susceptibility to the CIE. The current study investigated whether in idual differences in EF could predict in idual differences in CIE susceptibility. Participants completed several measures of EF subcomponents, including those of updating and inhibition, as well as set shifting, and a standard CIE task. The relationship between EF and CIE was then assessed using a correlation analysis of the EF and CIE measures, as well as structural equation modelling of the EF-subcomponent latent variable and CIE latent variable. Results showed that EF can predict susceptibility to the CIE, especially the factor of working-memory updating. These results further our understanding of the CIE’s cognitive antecedents and provide potential directions for real-world CIE intervention.
Publisher: Cambridge University Press (CUP)
Date: 05-09-2023
Publisher: Elsevier BV
Date: 10-2012
DOI: 10.1016/J.BIOPSYCHO.2012.06.005
Abstract: Electrophysiological studies have shown that obsessive-compulsive disorder (OCD) is associated with hyperactive performance monitoring, as indexed by the error-related negativity (ERN). The aim of the present study was to determine whether feedback monitoring is enhanced in addition to error monitoring among young adults with obsessive-compulsive symptomatology during performance of a learning task. The ERN was equivalent in litude for low and high OC groups. The feedback-related negativity (FRN) was more negative following presentation of incorrect feedback relative to correct feedback for the low OC group. For the high OC group, the FRN was equivalent in litude for correct and incorrect feedback. Young adults with high levels of obsessive-compulsive symptoms demonstrate aberrant feedback monitoring characterised by a lack of differentiation to the valence of feedback. This pattern of results may be indicative of a cognitive bias in outcome prediction associated with obsessive-compulsive symptomatology.
Publisher: Springer Science and Business Media LLC
Date: 02-2021
DOI: 10.1186/S13195-021-00774-Y
Abstract: Physical inactivity has been consistently linked to increased risk of cognitive decline however, studies examining the impact of exercise interventions on cognition have produced inconsistent findings. Some observational studies suggest exercise intensity may be important for inducing cognitive improvements however, this has yet to be thoroughly examined in older adult cohorts. The objective of the current study was to evaluate the effect of systematically manipulated high-intensity and moderate-intensity exercise interventions on cognition. This multi-arm pilot randomised clinical trial investigated the effects of 6 months of high-intensity exercise and moderate-intensity exercise, compared with an inactive control, on cognition. Outcome measures were assessed at pre- (baseline), post- (6 months), and 12 months post-intervention. Ninety-nine cognitively normal men and women (aged 60–80 years) were enrolled from October 2016 to November 2017. Participants that were allocated to an exercise group (i.e. high-intensity or moderate-intensity) engaged in cycle-based exercise two times per week for 6 months. Cognition was assessed using a comprehensive neuropsychological test battery. Cardiorespiratory fitness was evaluated by a graded exercise test. There was a dose-dependent effect of exercise intensity on cardiorespiratory fitness, whereby the high-intensity group experienced greater increases in fitness than the moderate-intensity and control groups. However, there was no direct effect of exercise on cognition. We did not observe a direct effect of exercise on cognition. Future work in this field should be appropriately designed and powered to examine factors that may contribute to in idual variability in response to intervention. This study is registered with the Australian New Zealand Clinical Trials Registry (ACTRN12617000643370). Registered on 3 May 2017—retrospectively registered. www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=372780
Publisher: Wiley
Date: 07-2015
Publisher: Informa UK Limited
Date: 03-11-2023
Publisher: Elsevier BV
Date: 2018
Publisher: Informa UK Limited
Date: 23-02-2016
Publisher: Informa UK Limited
Date: 31-01-2021
Publisher: Springer Science and Business Media LLC
Date: 02-12-2014
DOI: 10.1038/TP.2014.122
Publisher: Springer Science and Business Media LLC
Date: 22-05-2012
DOI: 10.1038/TP.2012.43
Publisher: Springer Science and Business Media LLC
Date: 31-03-2015
DOI: 10.1038/TP.2015.39
Abstract: In idual biological differences may contribute to the variability of outcomes, including cognitive effects, observed following electroconvulsive treatment (ECT). A narrative review of the research literature on carriage of the apolipoprotein E ɛ4 allele ( APOE-ɛ4 ) and the protein biomarker beta amyloid (Aβ) with ECT cognitive outcome was undertaken. ECT induces repeated brain seizures and there is debate as to whether this causes brain injury and long-term cognitive disruption. The majority of ECT is administered to the elderly (over age 65 years) with drug-resistant depression. Depression in the elderly may be a symptom of the prodromal stage of Alzheimer’s disease (AD). Carriage of the APOE-ɛ4 allele and raised cerebral Aβ are consistently implicated in AD, but inconsistently implicated in brain injury (and related syndromes) recovery rates. A paucity of brain-related recovery, genetic and biomarker research in ECT responses in the elderly was found: three studies have examined the effect of APOE-ɛ4 allele carriage on cognition in the depressed elderly receiving ECT, and two have examined Aβ changes after ECT, with contradictory findings. Cognitive changes in all studies of ECT effects were measured by a variety of psychological tests, making comparisons of such changes between studies problematic. Further, psychological test data-validity measures were not routinely administered, counter to current testing recommendations. The methodological issues of the currently available literature as well as the need for well-designed, hypothesis driven, longitudinal studies are discussed.
Location: Australia
No related grants have been discovered for Michael Weinborn.