Trevor T.-J. Chong's research while affiliated with St. Vincent's Hospital Melbourne and other places

Publications (23)

Preprint
Selection bias in information-search contributes to the formation of polarized echo-chambers of beliefs. However, the role of valence in information source selection remains poorly understood. In Experiment 1, participants won financial rewards depending on the outcomes of a set of lotteries. They were not shown these outcomes, but instead could ch...
Article
Humans routinely learn the value of actions by updating their expectations based on past outcomes - a process driven by reward prediction errors (RPEs). Importantly, however, implementing a course of action also requires the investment of effort. Recent work has revealed a close link between the neural signals involved in effort exertion and those...
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Objective The inter-individual variability in cognitive changes may be early indicators of major health events. We aimed to determine whether late-life cognitive trajectories were associated with incident dementia, persistent physical disability and all-cause mortality.Methods Data came from a cohort of older community-dwelling individuals aged 70...
Article
Importance: Dual decline in gait speed and cognition has been found to be associated with increased dementia risk in previous studies. However, it is unclear if risks are conferred by a decline in domain-specific cognition and gait. Objective: To examine associations between dual decline in gait speed and cognition (ie, global, memory, processin...
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Full-text available
People with Methamphetamine Use Disorder (PwMUD) spend substantial time and resources on substance use, which hinders their ability to explore alternate reinforcers. Gold-standard behavioural treatments attempt to remedy this by encouraging action towards non-drug reinforcers, but substance use often persists. We aimed to unravel the mechanistic dr...
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Prolonging survival in good health is a fundamental societal goal. However, the leading determinants of disability-free survival in healthy older people have not been well established. Data from ASPREE, a bi-national placebo-controlled trial of aspirin with 4.7 years median follow-up, was analysed. At enrolment, participants were healthy and withou...
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There is variability in cognitive aging between individuals. This study aimed to investigate cognitive aging trajectories, the associated modifiable factors, and the association of these trajectories with dementia. Community-dwelling older adults (n=19,114) without dementia or major cognitive impairment at inclusion were followed for up to 7 years,...
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Lower gait speed and grip strength are common in older adults. However, the results of lower motor function on cognitive outcomes have been mixed. We examined the longitudinal association between baseline slow gait speed and weak grip strength, alone and in combination, with risk of incident dementia or cognitive decline in a cohort of older adults...
Preprint
Humans routinely learn the value of actions by assessing their outcomes. Actions also require effort, and increasing evidence suggests that effort and learning share common neurophysiological substrates. Here, we asked whether effort could modulate teaching signals in a reinforcement learning task. Individuals (N=140) registered their choices by ex...
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Introduction: This study aimed to investigate cognitive aging trajectories, the associated sociodemographic characteristics, and the association of these trajectories with dementia. Methods: Generally healthy older adults (n = 19,114) were followed for up to 7 years, with regular cognitive assessments. Group-based trajectory modeling identified...
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Full-text available
Curiosity pervades all aspects of human behaviour and decision-making. Recent research indicates that the value of information is determined by its propensity to reduce uncertainty, and the hedonic value of the outcomes it predicts. Previous findings also indicate a preference for options that are freely chosen, compared to equivalently valued alte...
Article
Background Anticholinergic medications may increase risk of dementia and stroke, but prospective studies in healthy older people are lacking.Objective Compare risk of incident dementia and stroke by anticholinergic burden among initially healthy older people.DesignProspective cohort study.SettingPrimary care (Australia and USA).Participants19,114 c...
Article
Contemporary theoretical accounts of metacognition propose that action-related information is used in the computation of perceptual decision confidence. We investigated whether the amount of expended physical effort, or the ‘motoric sunk cost’ of a decision, influences perceptual decision confidence judgements in humans. In particular, we examined...
Article
Background Apathy is a disorder of motivation common to Huntington's disease (HD). Recent conceptual frameworks suggest that apathy is not unitary but consists of discrete subtypes (‘dimensions’). Which of the proposed dimensions are preferentially affected in HD, and how these dimensions evolve with disease progression is unknown. Objectives The...
Article
Methamphetamine use disorder involves continued use of the drug despite negative consequences. Such ‘compulsivity’ can be measured by reversal learning tasks, which involve participants learning action‐outcome task contingencies (acquisition‐contingency) and then updating their behaviour when the contingencies change (reversal). Using these paradig...
Preprint
Contemporary theoretical accounts of metacognition propose that action-related information is used in the computation of perceptual decision confidence. We investigated whether the amount of expended physical effort, or the ‘motoric sunk cost’ of a decision, influences perceptual decision confidence judgements in humans. In particular, we examined...
Article
Objective To determine the effect of low-dose aspirin vs placebo on incident all-cause dementia, incident Alzheimer disease (AD), mild cognitive impairment (MCI), and cognitive decline in older individuals. Methods Aspirin in Reducing Events in the Elderly (ASPREE) was a double-blind, placebo-controlled trial of low-dose aspirin. In the United Sta...
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Full-text available
Objective: The Hopkins Verbal Learning Test-Revised (HVLT-R) provides a measure of verbal learning and memory. The aim of this study was to provide normative performance data on the HVLT-R for community-dwelling older individuals according to ethno-racial group, age, gender, and years of completed education, in Australia and the U.S. Method: The AS...
Article
The prefrontal cortex (PFC) is a heterogeneous area that is critical to reward-based decision-making. In particular, the dorsal anterior cingulate cortex, ventromedial PFC and orbitofrontal cortex are frequently implicated in different aspects of choice behaviour. These regions receive projections from midbrain dopamine (DA) neurons and, in turn, p...
Article
Dopaminergic medication can induce severe addictive behaviours (e.g., pathological gambling) in susceptible Parkinson's disease (PD) patients. It is still unknown which particular neurocognitive processes become exacerbated or dysfunctional in PD patients with addictive behaviours. We sought to systematically review the relevant literature to ident...
Article
Drug use is a choice with immediate positive outcomes, but long-term negative consequences. Thus, the repeated use of drugs in the face of negative consequences suggests dysfunction in the cognitive mechanisms underpinning decision-making. This cognitive dysfunction can be mapped into three stages: the formation of preferences involving valuation o...

Citations

... Recent meta-analyses concluded that such use is associated with relatively large performance deficits on tests of psychomotor functioning, complex information processing speed, episodic memory, and executive function (EF), with smaller deficits on tests of attention and working memory, simple processing speed, visuospatial abilities, learning, and language Robinson et al., 2021;Scott et al., 2007). With regard to broadly defined EF, methamphetamine use is associated with impaired cognitive flexibility, decision making, and reward-or impulse-related functions, and with difficulty maintaining goal-oriented choices (Hekmat et al., 2011;Verdejo-Garcia and Chong, 2021). Hence, individuals with impaired EF may fail to anticipate the consequences of their actions, with detrimental social, medical, and financial outcomes (Mizoguchi and Yamada, 2019). ...
... In contrast, some individuals sustain a high level of cognitive function even with advanced age (3). The diversity of late-life cognitive trajectories delineates a spectrum with multiple subgroups having heterogeneous patterns of cognitive aging including high cognitive function over time, average cognitive aging, and low cognitive performance (4,5). ...
... Our findings are in line with recent evidence that autonomy boosts curiosity: Participants who watched a video of their choice (from a given set) self-reported higher interest in the topic than those who watched a video without a choice (Schutte & Malouff, 2019), and participants bid larger amounts for lotteries they chose than those they had not chosen ( Jiwa et al., 2021). However, in these recent studies, autonomy was confounded with preference. ...
... This is a troubling result given the associations between anticholinergic burden, including cumulative burden, and limitations in cognitive and physical function [3,4,10]. Studies have also revealed longitudinal impacts on dementia and poor physical functioning [28][29][30]. However, many of these studies examine the overall burden of anticholinergics and sedative CNS medications, but the individual impact of target medications is not known. ...
... In the 19th century, apathy entered the medical lexicon to describe indifference or inability to feel emotions (1). Other definitions such as loss of motivation, reduced goal-directed behavior, or a decrease in self-initiation of actions were proposed and subsequently added to the definition (2). The concept of apathy as a neuropsychiatric syndrome was first proposed by Marin in 1990 in an attempt to differentiate apathy from other clinical disorders. ...
... amphetamine addictions (57). Studies of methamphetamine use disorder also find these individuals to have altered learning with associated hyperactivation of striatal regions while performing reinforcement learning tasks in patients who have relapsed vs. those who have maintained abstinence (58,59). The conceptual link between reinforcement learning and addiction has been expanded to include the entire addiction spectrum, including behavioral addictions (BAs) (33). ...
... One possibility is that the amount of effort required in recognition test might affect retrospective confidence ratings. For example, in the study by Turner et al., (2021), participants gave higher retrospective confidence in perceptual decision making task when they invested more motor effort in reporting the decision. Turner et al. suggest that high level of effort invested into the decision might be interpreted post-hoc as a signal that the decision is likely to be correct. ...
... Recent studies by the ASPREE group show that daily low-dose aspirin did not reduce the risk of dementia, mild cognitive impairment, or cognitive decline. 27 This may partially explain why this trial found no protective effect of aspirin on fall risk. The increase in serious fall risk was not accompanied by an increase in fractures, in keeping with a previous report suggesting that only 10% to 15% of falls in older people are accompanied by fractures. ...
... Cognitive function was assessed at baseline and annually over follow-up, at up to six waves. The battery included 1) 3MS for global cognitive function (18), 2) single-letter (F) Controlled Oral Word Association Test (COWAT-F) for verbal fluency (19), 3) Hopkins Verbal Learning Test-Revised delayed recall task (HVLT-R) for episodic memory (20), and 4) Symbol-Digit Modalities Test (SDMT) for psychomotor speed (21). In addition, an overall score was generated by adding up the z-scores of the four cognitive tests (6,22). ...
... Dopaminergic neurons project to several brain regions, such as the prefrontal cortex (PFC), striatum, and hippocampus, and participate in high-level neural functions such as attention allocation, motor control, learning, and memory [40][41][42]. Distinct structural and functional cerebral abnormalities in the PFC, hippocampus, and striatum have been found in patients with ADHD [43,44]. e PFC and striatum have an important role in attention regulation, hyperactivity impulsivity, working memory, and emotional control [45]. ...