Biology subjects

Hanzal, S.

Publications and source records attributed to Hanzal, S..

4 recordsLinked to original sources

bioRxiv2025

Age differences in motivation drive performance during the sustained attention to response task

Young and older adults prioritise speed and accuracy differently during sustained attention tasks. While older adults generally show a preference of accuracy over speed, this is not always the case. The underlying factor behind this inconsistency may be motivational differences, with older participants compensating for a speed disadvantage with increased intrinsic motivation to perform well. We investigated this in a pre-registered study, using the Sustained aAttention to Response Task (SART) in young (n = 25, mean age = 19) and older adults (n = 25, mean age = 69.5). We matched participant accuracy by titrating response window length. Both groups achieved similar performance and strategy during the titration, enabling a comparison without confounds resulting from differences in default age-specific strategies. All participants were then monetarily encouraged to perform better in terms of accuracy. Both groups responded with an adaptive strategy of slowed reaction times and enhanced accuracy, but the young participants improved much more, outperforming older adults, and reversing the speed-accuracy strategies that are typically observed. In addition, older participants reported higher baseline levels of motivation alongside a reduced motivation to alter performance for money. So, while the older participants could match young participant performance in titration due to their higher baseline motivational levels, the young participants improved much more than older adults in response to the monetary incentive. From these findings we argue that older adults are intrinsically motivated to do well on tasks whereas younger age groups perform optimally only after incentivisation.

neuroscience↗

bioRxiv2024

EEG markers of vigilance, task-induced fatigue and motivation during sustained attention: Evidence for decoupled alpha- and beta-signatures

Reduced vigilance can be captured in measures of attentional lapses in sustained attention tasks, but just how these lapses relate to task-induced fatigue and motivation to maintain optimal performance is unclear. We used the sustained attention to response task (SART) to induce fatigue, and manipulated motivation levels for the last block of the task in young and older participants (N = 34), while recording EEG to track electrophysiological markers of vigilance change, fatigue and motivation. Despite significant increases in subjective fatigue and mind wandering over 45 minutes, no vigilance decline was observed. However, the age groups differed markedly in their response strategies from the outset (adopting distinct speed-accuracy trade-off strategies) with faster/more erroneous responses in the younger and slower/more accurate responses in the older participants. The subjective rises in fatigue/mind wandering were coupled with an increase in pre-stimulus alpha-power, whereas the post-stimulus activity revealed two distinguishable beta signatures: a fronto-central topography as a marker of response strategy and a fronto-parietal distribution modulated by motivation per se. Our results thus show three distinct neural patterns underpinning the effects of fatigue, response strategy and motivation and suggest a (motivational) cognitive control mechanism behind resetting of performance decrement, independent of persistent fatigue.

neuroscience↗

bioRxiv2023

Probing sustained attention and fatigue across the lifespan

Trait fatigues reflects tiredness that persists throughout a prolonged period, whereas state fatigue is defined to be short term after "intense and/or prolonged effort". We investigated the impact of prolonged sustained attention (using the SART task) on both trait and state fatigue levels in the general population. A JsPsych online version of the SART task was undertaken by 115 participants, stratified across the whole adult lifespan. While pre-task trait fatigue was a strong indicator of the initial state fatigue levels, undergoing the task itself induced an increase in reported subjective state fatigue, as well as reduced energy. Consistent with this finding, greater subjective state fatigue levels were associated with reduced accuracy. In addition, age was the best predictor of inter-participant accuracy (the older the participants, the greater the accuracy), and learning (i.e., task duration reducing reaction times). Moreover, a ceiling effect occurred where participants with higher trait fatigue did not experience greater state fatigue changes relative to those with low trait scores. In summary, we found improved accuracy in older adults, as well as a tight coupling between state fatigue and SART performance decline (in an online environment). The findings warrant further investigation into fatigue as a dynamic, task-dependent state and into SART task performance as an objective measure and inducer of fatigue.

neuroscience↗

bioRxiv2023

Developmental changes in individual alpha frequency: Recording EEG data during public engagement events

Statistical power in cognitive neuroimaging experiments is often very low. Low sample size can reduce the likelihood of detecting real effects (false negatives) and increase the risk of detecting non-existing effects by chance (false positives). Here we document our experience of leveraging a relatively unexplored method of collecting a large sample size for simple electroencephalography (EEG) studies: by recording EEG in the community during public engagement and outreach events. We collected data from 346 participants (189 females, age range 6-76 years) over 6 days, totalling 29 hours, at local science festivals. Alpha activity (6-15 Hz) was filtered from 30 seconds of signal, recorded from a single electrode placed between the occipital midline (Oz) and inion (Iz) while participants rested with their eyes closed. A total of 289 good quality datasets were obtained. Using this community-based approach, we were able to replicate controlled, lab-based findings: IAF increased during childhood, reaching a peak frequency of 10.28 Hz at 28.1 years old, and slowed again in middle and older age. Total alpha power decreased linearly, but the aperiodic-adjusted alpha power did not change over the lifespan. Aperiodic slopes and intercepts were highest in the youngest participants. There were no associations between these EEG indexes and self-reported fatigue, measured by the Multidimensional Fatigue Inventory. Finally, we present a set of important considerations for researchers who wish to collect EEG data within public engagement and outreach environments.

neuroscience↗