The Brain's Reward Response Occurs Even Without Actual Reward!

Variability in competitive decision-making speed and quality against exploiting and exploitative opponents

A presumption in previous work has been that sub-optimality in competitive performance following loss is the result of a reduction in decision-making time (i.e., post-error speeding). The main goal of this paper is to test the relationship between decision-making speed and quality, with the hypothesis that slowing down decision-making should increase the likelihood of successful performance in cases where a model of opponent domination can be implemented. Across Experiments 1–3, the speed and quality of competitive decision-making was examined in a zero-sum game as a function of the nature of the opponent (unexploitable, exploiting, exploitable). Performance was also examined against the nature of a credit (or token) system used as a within-experimental manipulation (no credit, fixed credit, variable credit). To compliment reaction time variation as a function of outcome, both the fixed credit and variable credit conditions were designed to slow down decision-making, relative to a no credit condition where the game could be played in quick succession and without interruption. The data confirmed that (a) self-imposed reductions in processing time following losses (post-error speeding) were causal factors in determining poorer-quality behaviour, (b) the expression of lose-shift was less flexible than the expression of win-stay, and, (c) the use of a variable credit system may enhance the perceived control participants have against exploitable opponents. Future work should seek to disentangle temporal delay and response interruption as determinants of decision-making quality against numerous styles of opponency.

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 may be mutual attempts to self-regulate performance during competition. In this way, increased exposure to positive outcomes (real or imagined) may help to weight the output of the more diligent and analytic System 2, relative to the impulsive and intuitive System 1.

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 an early index of visual attention (N1), a later index 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.

Event-Related Potentials in Relation to Risk-Taking: A Systematic Review

Event-related potentials (ERPs) have been used to investigate neural mechanisms underlying risk-related decisions over the last 16 years. We aimed to systematically evaluate associations between risk-taking and ERP components elicited during decisions and following feedback. A total of 79 articles identified from PsychINFO and PubMed databases met the inclusion criteria. Selected articles assessed early ERP components (feedback-related negativity/FRN, error-related negativity/ERN, and medial frontal negativity/MFN) and the mid-latency P3 component, all using gambling paradigms that involved selecting between choices of varying risk (e.g., Iowa Gambling Task, Balloon Analogue Risk Task, and two-choice gambling tasks). The P3 component was consistently enhanced to the selection of risky options and when positive feedback (as compared to negative feedback) was provided. Also consistently, the early negative components were found to be larger following feedback indicating monetary losses as compared to gains. In the majority of studies reviewed here, risk was conceptualized in the context of simple economical decisions in gambling tasks. As such, this narrow concept of risk might not capture the diversity of risky decisions made in other areas of everyday experience, for example, social, health, and recreational risk-related decisions. It therefore remains to be seen whether the risk-sensitivity of the ERP components reviewed here generalizes to other domains of life.