ORCID Profile
0000-0003-2704-5623
Current Organisations
The University of Newcastle
,
University of Newcastle Australia
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Publisher: Elsevier BV
Date: 11-2022
DOI: 10.1016/J.EXGER.2022.111971
Abstract: People's perceptions of the mental effort required for everyday activities may drive variation in the relationships between lifestyles and cognitive ability. We asked n = 259 healthy older adults aged 60 to 70 years (90 males, 169 females) to provide a rating of the Perceived Mental Effort (PME) for each activity instance they recalled over a 48-h period as part of a time-use recall. PME was rated on a 9-point scale from "very, very low" (score of 1) to "very, very high" (score of 9). Across the entire s le, participants rated a total of 196 different activities and 17,433 activity instances. The mean PME for in idual activities was 3.50 ± 1.58. PMEs varied significantly by activity domain, with highest ratings being for Work (5.48 ± 1.72) and the lowest for Self-Care (2.89 ± 0.98). In multivariate analyses, PME ratings were higher in males than females (+0.30), PMEs were higher later in the day, increased with task duration, and decreased with age (all p < 0.0001). Time-weighted average in idual PMEs across the two days of recall ranged from 1.86 to 6.50, and were 0.3 units higher for males, but unrelated to age. Repeated intra-in idual PME ratings for the same activity were very reliable (ICC = 0.995, mean absolute difference = 0.03 ± 0.17). PMEs show promise as a reliable measure of mental effort.
Publisher: Wiley
Date: 12-01-2023
DOI: 10.1111/PSYP.14241
Abstract: In this study, we implement joint modeling of behavioral and single‐trial electroencephalography (EEG) data derived from a cued‐trials task‐switching paradigm to test the hypothesis that trial‐by‐trial adjustment of response criterion can be linked to changes in the event‐related potentials (ERPs) elicited during the cue‐target interval (CTI). Specifically, we assess whether ERP components associated with preparation to switch task and preparation of the relevant task are linked to a response criterion parameter derived from a simple diffusion decision model (DDM). Joint modeling frameworks characterize the brain‐behavior link by simultaneously modeling behavioral and neural data and implementing a linking function to bind these two submodels. We examined three joint models: The first characterized the core link between EEG and criterion, the second added a switch preparation input parameter and the third also added a task preparation input parameter. The criterion‐EEG link was strongest just before target onset. Inclusion of switch and task preparation parameters did not improve the performance of the criterion‐EEG link but was necessary to accurately model the ERP waveform morphology. While we successfully jointly modeled latent model parameters and EEG data from a task‐switching paradigm, these findings show that customized cognitive models are needed that are tailored to the multiple cognitive control processes underlying task‐switching performance. This is the first paper to implement joint modeling of behavioral measures and single‐trial electroencephalography (EEG) data derived from the cue‐target interval in a cued‐trials task‐switching paradigm. Model hyperparameters showed a strong link between response criterion and the pre‐target negativity litude. Additional parameters (switch preparation, task preparation) were necessary to model the cue‐locked ERP waveform morphology. This is consistent with multiple cognitive control processes underlying proactive control and points to the need for more nuanced models of task‐switching performance.
Publisher: Springer Science and Business Media LLC
Date: 22-05-2019
DOI: 10.3758/S13415-019-00722-2
Abstract: Neurobiological models explain increased risk-taking behaviours in adolescence and young adulthood as arising from staggered development of subcortical reward networks and prefrontal control networks. In this study, we examined whether in idual variability in impulsivity and reward-related mechanisms is associated with higher level of engagement in risky behaviours and vulnerability to maladaptive outcomes and whether this relationship is mediated by cognitive control ability. A community s le of adolescents, young adults, and adults (age = 15-35 years) completed self-report measures and behavioural tasks of cognitive control, impulsivity, and reward-related mechanisms, and self-reported level of maladaptive outcomes. Behavioural, event-related potential (ERP), and multivariate pattern analysis (MVPA) measures of proactive control were derived from a task-switching paradigm. Adolescents, but not young adults, reported higher levels of impulsivity, reward-seeking behaviours and maladaptive outcomes than adults. They also had lower cognitive control ability, as measured by both self-report and task-based measures. Consistent with models of risk-taking behaviour, self-reported level of cognitive control mediated the relationship between self-reported levels of impulsivity and psychological distress, but the effect was not moderated by age. In contrast, there was no mediation effect of behavioural or EEG-based measures of cognitive control. These findings suggest that in idual variability in cognitive control is more crucial to the relationship between risk-taking/impulsivity and outcomes than age itself. They also highlight large differences in measurement between self-report and task-based measures of cognitive control and decision-making under reward conditions, which should be considered in any studies of cognitive control.
Publisher: Elsevier BV
Date: 04-2019
Publisher: Cold Spring Harbor Laboratory
Date: 31-07-2021
DOI: 10.1101/2021.07.28.21261299
Abstract: Approximately 40% of late-life dementia may be prevented by addressing modifiable risk factors, including physical activity and diet. Yet, it is currently unknown how multiple lifestyle factors interact to influence cognition. The ACTIVate Study aims to 1) Explore associations between 24-hour time-use and diet compositions with changes in cognition and brain function and 2) Identify durations of time-use behaviours and the dietary compositions to optimise cognition and brain function. This three-year prospective longitudinal cohort study will recruit 448 adults aged 60-70 years across Adelaide and Newcastle, Australia. Time-use data will be collected through wrist-worn activity monitors and the Multimedia Activity Recall for Children and Adults (MARCA). Dietary intake will be assessed using the Australian Eating Survey food frequency questionnaire. The primary outcome will be cognitive function, assessed using the Addenbrooke’s Cognitive Examination-III (ACE-III). Secondary outcomes include structural and functional brain measures using Magnetic Resonance Imaging (MRI), cerebral arterial pulse measured with Diffuse Optical Tomography (Pulse-DOT), neuroplasticity using simultaneous Transcranial Magnetic Stimulation (TMS) and Electroencephalography (EEG), and electrophysiological markers of cognitive control using event-related potential (ERP) and time-frequency analyses. Compositional data analysis, testing for interactions between time-point and compositions, will assess longitudinal associations between dependent (cognition, brain function) and independent (time-use and diet compositions) variables. The ACTIVate Study will be the first to examine associations between time-use and diet compositions, cognition and brain function. Our findings will inform new avenues for multidomain interventions that may more effectively account for the co-dependence between activity and diet behaviours for dementia prevention. Ethics approval has been obtained from University of South Australia’s Human Research Ethics committee (202639). Findings will be disseminated through peer reviewed manuscripts, conference presentations, targeted media releases and community engagement events. Australia New Zealand Clinical Trials Registry (ACTRN12619001659190). The ACTIVate Study will collect comprehensive measures of lifestyle behaviours and dementia risk over time in 448 older adults aged 60-70 years. Using newly developed Compositional Data Analysis (CoDA) techniques we will examine the associations between time-use and diet compositions, cognition and brain function. Data will inform the development of a digital tool to help older adults obtain personalised information about how to reduce their risk of cognitive decline based on changes to time use and diet. Recruitment will be focussed on older adults to maximise the potential of making an impact on dementia prevention in the next 10 years. Findings may not be generalisable to younger adults.
Publisher: Frontiers Media SA
Date: 24-11-2022
DOI: 10.3389/FNHUM.2022.1051793
Abstract: Physical activity, sedentary behaviour and sleep are associated with cognitive function in older adults. However, these behaviours are not independent, but instead make up exclusive and exhaustive components of the 24-h day. Few studies have investigated associations between 24-h time-use composition and cognitive function in older adults. Of these, none have considered how the quality of sleep, or the context of physical activity and sedentary behaviour may impact these relationships. This study aims to understand how 24-h time-use composition is associated with cognitive function across a range of domains in healthy older adults, and whether the level of recreational physical activity, amount of television (TV) watching, or the quality of sleep impact these potential associations. 384 healthy older adults (age 65.5 ± 3.0 years, 68% female, 63% non-smokers, mean education = 16.5 ± 3.2 years) participated in this study across two Australian sites (Adelaide, n = 207 Newcastle, n = 177). Twenty-four-hour time-use composition was captured using triaxial accelerometry, measured continuously across 7 days. Total time spent watching TV per day was used to capture the context of sedentary behaviours, whilst total time spent in recreational physical activity was used to capture the context of physical activity (i.e., recreational accumulation of physical activity vs. other contexts). Sleep quality was measured using a single item extracted from the Pittsburgh Sleep Quality Index. Cognitive function was measured using a global cognition index (Addenbrooke’s Cognitive Examination III) and four cognitive domain composite scores (derived from five tests of the Cambridge Neuropsychological Test Automated Battery: Paired Associates Learning One Touch Stockings of Cambridge Multitasking Reaction Time Verbal Recognition Memory). Pairwise correlations were used to describe independent relationships between time use variables and cognitive outcomes. Then, compositional data analysis regression methods were used to quantify associations between cognition and 24-h time-use composition. After adjusting for covariates and false discovery rate there were no significant associations between time-use composition and global cognition, long-term memory, short-term memory, executive function, or processing speed outcomes, and no significant interactions between TV watching time, recreational physical activity engagement or sleep quality and time-use composition for any cognitive outcomes. The findings highlight the importance of considering all activities across the 24-h day against cognitive function in older adults. Future studies should consider investigating these relationships longitudinally to uncover temporal effects.
Publisher: Elsevier
Date: 2021
Publisher: Wiley
Date: 05-2020
DOI: 10.1111/PSYP.13533
Abstract: Event-related potentials (ERPs) and total time-frequency power analyses have shown that performance costs during task switching are related to differential preparation to switch tasks (switch cost) and repeat the same task (mixing cost) during both proactive control (cue-to-target interval CTI) and reactive control (post-target). The time-frequency EEG signal is comprised of both phase-locked activity (associated with stimulus-specific processes) and nonphase-locked activity (represents processes thought to persist over longer timeframes and do not contribute to the average ERP). In the present study, we used a cued task-switching paradigm to examine whether phase-locked and nonphase-locked power are differentially modulated by switch and mixing effects in intervals associated with the need for proactive control (CTI) and reactive control (post-target interval). Phase-locked activity was observed in the theta and alpha bands, closely resembled that seen for total power, and was consistent with switch and mixing ERP positivities. Nonphase-locked analyses showed theta and alpha power effects for both switch and mixing effects early in the CTI and as well as more sustained alpha and beta activity around cue onset, and extending from mid-CTI into the post-target interval. Nonphase-locked activity in pretarget alpha and posttarget theta power were both correlated with response time mixing cost. These findings provide novel insight into phase-locked and nonphase-locked activity associated with switch and mixing costs that are not evident with ERP or total time-frequency analyses.
Publisher: BMJ
Date: 2022
DOI: 10.1136/BMJOPEN-2020-047888
Abstract: Approximately 40% of late-life dementia may be prevented by addressing modifiable risk factors, including physical activity and diet. Yet, it is currently unknown how multiple lifestyle factors interact to influence cognition. The ACTIVate Study aims to (1) explore associations between 24-hour time-use and diet compositions with changes in cognition and brain function and (2) identify duration of time-use behaviours and the dietary compositions to optimise cognition and brain function. This 3-year prospective longitudinal cohort study will recruit 448 adults aged 60–70 years across Adelaide and Newcastle, Australia. Time-use data will be collected through wrist-worn activity monitors and the Multimedia Activity Recall for Children and Adults. Dietary intake will be assessed using the Australian Eating Survey food frequency questionnaire. The primary outcome will be cognitive function, assessed using the Addenbrooke’s Cognitive Examination-III. Secondary outcomes include structural and functional brain measures using MRI, cerebral arterial pulse measured with diffuse optical tomography, neuroplasticity using simultaneous transcranial magnetic stimulation and electroencephalography, and electrophysiological markers of cognitive control using event-related potential and time frequency analyses. Compositional data analysis, testing for interactions between time point and compositions, will assess longitudinal associations between dependent (cognition, brain function) and independent (time-use and diet compositions) variables. The ACTIVate Study will be the first to examine associations between time-use and diet compositions, cognition and brain function. Our findings will inform new avenues for multidomain interventions that may more effectively account for the co-dependence between activity and diet behaviours for dementia prevention. Ethics approval has been obtained from the University of South Australia’s Human Research Ethics committee (202639). Findings will be disseminated through peer-reviewed manuscripts, conference presentations, targeted media releases and community engagement events. Australia New Zealand Clinical Trials Registry (ACTRN12619001659190).
Publisher: Wiley
Date: 29-06-2021
DOI: 10.1002/HBM.25573
Abstract: During task‐switching paradigms, both event‐related potentials and time‐frequency analyses show switch and mixing effects at frontal and parietal sites. Switch and mixing effects are associated with increased power in broad frontoparietal networks, typically stronger in the theta band (~4–8 Hz). However, it is not yet known whether mixing and switch costs rely upon common or distinct networks. In this study, we examine proactive and reactive control networks linked to task switching and mixing effects, and whether strength of connectivity in these networks is associated with behavioural outcomes. Participants ( n = 197) completed a cued‐trials task‐switching paradigm with concurrent electroencephalography, after substantial task practice to establish strong cue‐stimulus–response representations. We used inter‐site phase clustering, a measure of functional connectivity across electrode sites, to establish cross‐site connectivity from a frontal and a parietal seed. Distinct theta networks were activated during proactive and reactive control periods. During the preparation interval, mixing effects were associated with connectivity from the frontal seed to parietal sites, and switch effects with connectivity from the parietal seed to occipital sites. Lateralised occipital connectivity was common to both switch and mixing effects. After target onset, frontal and parietal seeds showed a similar pattern of connectivity across trial types. These findings are consistent with distinct and common proactive control networks and common reactive networks in highly practised task‐switching performers.
No related grants have been discovered for Montana Hunter.