Biology subjects

Dyson, B.

Publications and source records attributed to Dyson, B..

3 recordsLinked to original sources

bioRxiv2022

Fleeting Effects of Incentives: Adult Age Differences in ERP Measures of Motivated Attention

Reward-based motivation is associated with transient and sustained dopaminergic activity and with modulatory effects on attention and cognitive control. Age-related changes in the dopamine system are well documented, but little is known about age differences in the temporal dynamics of motivational influences on cognitive functions. The current study examined the effects of financial incentives on visual attention using event-related potentials (ERPs). Participants (26 younger, aged 18-33; 24 older, aged 65-95) completed an incentivized flanker task in which trial-level incentive cues signaled the availability of performance-contingent reward, and subsequent alerting cues signaled the onset of the flanker target. ERP components of interest included incentive-cue P2 and CNV, alerting-cue N1, target N1, and target P3. Transient effects of incentives were assessed by comparing ERP amplitudes across incentive and non-incentive trials from mixed-incentive blocks. Younger adults showed transient effects of incentives on all components, whereas older adults showed effects for incentive-cue P2 and alerting-cue N1 only. Sustained effects of incentives were assessed by comparing ERP amplitudes across non-incentive trials from mixed-incentive blocks and non-incentive trials from pure non-incentive blocks. Both age groups showed sustained effects of incentives on cue-locked ERPs, but only younger adults showed sustained effects on target-locked ERPs. Reaction-time patterns mirrored the ERP findings, in that younger adults showed greater incentive-based modulation than older adults. Overall, these findings suggest that both transient and sustained effects of incentives on visual attention are more fleeting for older than younger adults, consistent with widespread alterations in dopaminergic neuromodulation in aging.

neuroscience↗

bioRxiv2019

Behavioural and neural interactions between objective and subjective performance in a Matching Pennies game

To examine the behavioural and neural interactions between objective and subjective performance during competitive decision-making, participants completed a Matching Pennies game where win-rates were fixed within three conditions (win > lose, win = lose, win < lose) and outcomes were predicted at each trial. Using random behaviour as the hallmark of optimal performance, we observed item (heads), contingency (win-stay, lose-shift) and combinatorial (HH, HT, TH, TT) biases across all conditions. Higher-quality behaviour represented by a reduction in combinatorial bias was observed during high win-rate exposure. In contrast, over-optimism biases were observed only in conditions where win rates were equal to, or less than, loss rates. At a group level, a neural measure of outcome evaluation (feedback-related negativity; FRN) indexed the binary distinction between positive and negative outcome. At an individual level, increased belief in successful performance accentuated FRN amplitude differences between wins and losses. Taken together, the data suggest that objective experiences of, or, subjective beliefs in, the predominance of positive outcomes are mutual attempts to self-regulate performance during competition. In this way, increased exposure to positive outcomes (real or imagined) help to weight the output of the more diligent and analytic System 2, relative to the impulsive and intuitive System 1.

neuroscience↗

bioRxiv2019

Behavioural and neural limits in competitive decision making: The roles of outcome, opponency and observation

To understand the boundaries we set for ourselves in terms of environmental responsibility during competition, we examined a neural index of outcome valence (feedback-related negativity; FRN) in relation to earlier indices of visual attention (N1), later indices of motivational significance (P3), and, eventual behaviour. In Experiment 1 (n=36), participants either were (play) or were not (observe) responsible for action selection. In Experiment 2 (n=36), opponents additionally either could (exploitable) or could not (unexploitable) be beaten. Various failures in reinforcement learning expression were revealed including large-scale approximations of random behaviour. Against unexploitable opponents, N1 determined the extent to which negative and positive outcomes were perceived as distinct categories by FRN. Against exploitable opponents, FRN determined the extent to which P3 generated neural gain for future events. Differential activation of the N1 - FRN - P3 processing chain provides a framework for understanding the behavioural dynamism observed during competitive decision making.

neuroscience↗