Psychological trait differences between ultrarunners (completing more than a standard 42.195 km marathon) and sub-ultrarunners (≤42.195 km) have been assumed, but not robustly examined.
View Article and Find Full Text PDFBackground: Multiple sclerosis (MS) is a chronic neurological condition and the leading cause of non-traumatic disability in young adults. MS pathogenesis leads to the death of oligodendrocytes, demyelination, and progressive central nervous system neurodegeneration. Endogenous remyelination occurs in people with MS (PwMS) but is insufficient to repair the damage.
View Article and Find Full Text PDFThe ability to inhibit movements is an essential component of a healthy executive control system. Two distinct but commonly used tasks to assess motor inhibition are the stop signal task (SST) and the anticipated response inhibition (ARI) task. The SST and ARI tasks are similar in that they both require cancelation of a prepotent movement; however, the SST involves cancelation of a speeded reaction to a temporally unpredictable signal, while the ARI task involves cancelation of an anticipated response that the participant has prepared to enact at a wholly predictable time.
View Article and Find Full Text PDFPast research has found that the speed of the action cancellation process is influenced by the sensory modality of the environmental change that triggers it. However, the effect on selective stopping processes (where participants must cancel only one component of a multicomponent movement) remains unknown, despite these complex movements often being required as we navigate our busy modern world. Thirty healthy adults (mean age = 31.
View Article and Find Full Text PDFIn everyday life, we constantly make decisions about actions to be performed subsequently. Research on motor decision making has provided empirical evidence for an influence of decision uncertainty on movement execution in young adults. Further, decision uncertainty was suggested to be increased in older adults due to limited cognitive resources for the integration of information and the prediction of the decision outcomes.
View Article and Find Full Text PDFThe prefrontal cortex (PFC) governs the ability to rapidly cancel planned movements when no longer appropriate (motor inhibition) and ignore distracting stimuli (perceptual inhibition). It is unclear to what extent these processes interact, and how they are impacted by age. The interplay between perceptual and motor inhibition was investigated using a Flanker Task, a Stop Signal Task and a combined Stop Signal Flanker Task in healthy young (n = 33, Mean = 24 years) and older adults (n = 32, Mean = 71 years).
View Article and Find Full Text PDFResponse inhibition is a key attribute of human executive control. Standard stop-signal tasks require countermanding a single response; the speed at which that response can be inhibited indexes the efficacy of the inhibitory control networks. However, more complex stopping tasks, where one or more components of a multi-component action are cancelled (i.
View Article and Find Full Text PDFThe efficacy of transcranial alternating current stimulation (tACS) is thought to be brain state-dependent, such that tACS during task performance would be hypothesised to offer greater potential for improving performance compared to tACS at rest. However, to date, no empirical study has tested this postulation. The current study compared the effects of dual-site beta tACS applied during a stop signal task (online) to the effects of the same tACS protocol applied prior to the task (offline) and a sham control stimulation in 53 young, healthy adults (32 female; 18-35 yrs).
View Article and Find Full Text PDFThe ability to stop simple ongoing actions has been extensively studied using the stop signal task, but less is known about inhibition in more complex scenarios. Here we used a task requiring bimanual responses to go stimuli, but selective inhibition of only one of those responses following a stop signal. We assessed how proactive cues affect the nature of both the responding and stopping processes, and the well-documented stopping delay (interference effect) in the continuing action following successful stopping.
View Article and Find Full Text PDFRapid-choice decision-making is biased by prior probability of response alternatives. Conventionally, prior probability effects are assumed to selectively affect, response threshold, which determines the amount of evidence required to trigger a decision. However, there may also be effects on the rate at which evidence is accumulated and the time required for non-decision processes (e.
View Article and Find Full Text PDFInhibiting ongoing responses when environmental demands change is a critical component of motor control. Experimentally, the stop signal task (SST) represents the gold standard response inhibition paradigm. However, an emerging body of evidence suggests that the SST conflates two dissociable sources of inhibition, namely an involuntarily pause associated with attentional capture and the (subsequent) voluntary cancellation of action.
View Article and Find Full Text PDFCogn Affect Behav Neurosci
February 2023
Response-selective stopping requires cancellation of only one component of a multicomponent action. While research has investigated how delays to the continuing action components ("stopping interference") can be attenuated by way of contextual cues of the specific stopping demands ("foreknowledge"), little is known of the underlying neural mechanisms. Twenty-seven, healthy, young adults undertook a multicomponent stop-signal task.
View Article and Find Full Text PDFBackground: The worldwide prevalence of dementia is rapidly rising. Alzheimer's disease (AD), accounts for 70% of cases and has a 10-20-year preclinical period, when brain pathology covertly progresses before cognitive symptoms appear. The 2020 Lancet Commission estimates that 40% of dementia cases could be prevented by modifying lifestyle/medical risk factors.
View Article and Find Full Text PDFBackground: Prior work suggests there may be greater reliance on executive function for walking in older people. The pre-frontal cortex (PFC), which controls aspects of executive function, is known to be active during dual-task walking (DTW). However, there is debate on how PFC activity during DTW is impacted by ageing and the requirements of the cognitive task.
View Article and Find Full Text PDFHuman movement is influenced by various cognitive processes, such as bias, that dynamically shape competing movement representations. However, the neurophysiological mechanisms underlying the effects of bias on movement selection across the lifespan remains poorly understood. Healthy young (n = 21) and older (n = 20) adults completed a choice reaction-time task necessitating left- or right-hand responses to imperative stimuli (IS).
View Article and Find Full Text PDFBackground: Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive tool commonly used to drive neural plasticity in the young adult and aged brain. Recent data from mouse models have shown that even at subthreshold intensities (0.12 T), rTMS can drive neuronal and glial plasticity in the motor cortex.
View Article and Find Full Text PDFA wide body of literature suggests that transcranial direct current stimulation (tDCS) administered over the prefrontal cortex can improve executive function - including decision-making and inhibitory control - in healthy young adults. However, the effects of tDCS in older adults are largely unknown. Here, using a double-blind, sham-controlled approach, changes in a combined perceptual decision-making and inhibitory control task were assessed before and after the application of tDCS (1 mA, 20 minute) targeting the right inferior frontal gyrus (rIFG) or pre-supplementary motor area (preSMA) in 42 young (18-34 years) and 41 older (60-80 years) healthy adults.
View Article and Find Full Text PDFWhile upper limb reaches are often made in a feed-forward manner, visual feedback during the movement can be used to guide the reaching hand towards a target. In Parkinson's disease (PD), there is evidence that the utilisation of this visual feedback is increased. However, it is unclear if this is due solely to the characteristic slowness of movements in PD providing more opportunity for incorporating visual feedback to modify reach trajectories, or whether it is due to cognitive decline impacting (feed-forward) movement planning ability.
View Article and Find Full Text PDFRecent evidence suggests increased activity of the pre-frontal cortex (PFC) is associated with sensorimotor disturbances of standing balance. Here we manipulate sensorimotor inputs and concurrently load cognitive resources in order to investigate the functional role of PFC activity during standing balance, and how this changes with healthy ageing. Healthy younger (n = 24; mean age = 20.
View Article and Find Full Text PDFA lack of diversity limits progression of science. Thus, there is an urgent demand in science and the wider community for approaches that increase diversity, including gender diversity. We developed a novel, data-driven approach to conference speaker selection that identifies potential speakers based on scientific impact metrics that are frequently used by researchers, hiring committees, and funding bodies, to convincingly demonstrate parity in the quality of peer-reviewed science between men and women.
View Article and Find Full Text PDFBase-rate neglect is a failure to sufficiently bias decisions toward a priori more likely options. Given cognitive and neurocognitive model-based evidence indicating that, in speeded choice tasks, (a) age-related slowing is associated with higher and less flexible overall evidence thresholds (response caution) and (b) gains in speed and accuracy in relation to base-rate bias require flexible control of choice-specific evidence thresholds (response bias), it was hypothesized that base-rate neglect might increase with age due to compromised flexibility, and so optimality, of response bias. We administered a computer-based perceptual discrimination task to 20 healthy older (63-78 years) and 20 younger (18-28 years) adults where base-rate direction was either variable or constant over trials and so required more or less flexible bias control.
View Article and Find Full Text PDFResponse inhibition, the ability to withhold a dominant and prepotent response following a change in circumstance or sensory stimuli, declines with advancing age. While non-invasive brain stimulation (NiBS) has shown promise in alleviating some cognitive and motor functions in healthy older individuals, NiBS research focusing on response inhibition has mostly been conducted on younger adults. These extant studies have primarily focused on modulating the activity of distinct neural regions known to be critical for response inhibition, including the right inferior frontal gyrus (rIFG) and the pre-supplementary motor area (pre-SMA).
View Article and Find Full Text PDFRepetitive transcranial magnetic stimulation (rTMS) is commonly used to modulate cortical plasticity in clinical and non-clinical populations. Clinically, rTMS is delivered to targeted regions of the cortex at high intensities (>1 T). We have previously shown that even at low intensities, rTMS induces structural and molecular plasticity in the rodent cortex.
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