Dissociable Effects of Monetary, Liquid, and Social Incentives on Motivation and Cognitive Control

Abstract

Humans are social creatures and, as such, can be motivated by aspects of social life (e.g., approval from others) to guide decision-making in everyday contexts. Indeed, a common view is that people may have stronger orientation toward social goals or incentives relative to other incentive modalities, such as food or money. However, current studies have only rarely addressed how social incentives compare to other types of rewards in motivating goal-directed behavior. The current study tested this claim; across two separate experiments, the effects of liquid and social incentives were compared in terms of their subsequent impact on task performance and self-reported affect and motivation. Critically, valenced social incentives offered both ecological validity (short video clips-Experiment 1) and continuity with prior stimuli used in the social reward and motivation literature (static images-Experiment 2) when examining their effect on behavior. Across both studies, the results replicate and extend prior work, demonstrating robust effects of liquid incentives on task performance and self-reported affect and motivation, while also supporting an interpretation of weaker motivational and affective effects for social incentives. These patterns of results highlight the complex and wide-ranging effects of social incentives and call into question the effectiveness of social incentives, relative to other incentive modalities, in motivating behavior.

Dorsal Anterior Cingulate Cortex Encodes the Integrated Incentive Motivational Value of Cognitive Task Performance

“…We found that different types of motivational incentives are integrated to modulate cognitive task performance. Specifically, we estimated a general linear mixed model with contrast coded monetary reward (Low = -1, Medium = 0, High = 1) and liquid valence (Saltwater = -1, Neutral = 0, Juice = 1) as fixed effects with participant as a random effect [Reward Rate ~ Money Thus, the liquid effects on reward rates were primarily driven by impaired performance when saltwater was offered as incentive feedback (Figure 1B; although note that in our prior behavioral studies, we observed both performance facilitation effects due to juice, as well as performance impairments due to saltwater (Crawford et al, 2020;Yee et al, 2016Yee et al, , 2019). It is noteworthy that we did not detect an interaction between monetary rewards and liquid incentives, suggesting the presence of pure additive effects.…”

Dorsal Anterior Cingulate Cortex Encodes the Integrated Incentive Motivational Value of Cognitive Task Performance

“…Post-hoc analyses further revealed a significant difference between neutral and saltwater [b=.03 t=2.12, p=.034], but no significant effects between juice and neutral [b=.00, t=.08, p=.936]. Thus, the liquid effects on reward rates were primarily driven by impaired performance when saltwater was offered as incentive feedback (Figure 1B; although note that in our prior behavioral studies, we observed both performance facilitation effects due to juice, as well as performance impairments due to saltwater (Yee et al ., 2016, 2019; Crawford et al ., 2020)). Critically, the lack of interaction between incentives suggests a combined, additive effect on liquid incentives and monetary rewards on performance.…”

“…We found that different types of motivational incentives are integrated to modulate cognitive task performance. Specifically, we estimated a general linear mixed model with contrast coded monetary reward (Low = -1, Medium = 0, High = 1) and liquid valence (Saltwater = -1, Thus, the liquid effects on reward rates were primarily driven by impaired performance when saltwater was offered as incentive feedback ( Figure 1B; although note that in our prior behavioral studies, we observed both performance facilitation effects due to juice, as well as performance impairments due to saltwater (Crawford et al, 2020;Yee et al, 2016Yee et al, , 2019 were dummy coded (switch=1, repeat=0), money and liquid were contrast coded same as in previous models. This lack of effect is not particularly surprising, given that switch costs were overall quite small under incentive conditions (~20 ms), and so likely did not have sufficient dynamic range to exhibit sensitivity to the more subtle parametric incentive manipulations.…”

“…Broadly, given the diversity of incentives that people encounter on a daily basis (e.g., social rewards), an open question relates to the challenge of how people evaluate and integrate multiple diverse types of incentives in the real world (Lehner et al ., 2017). Thus, our innovative approach lays the critical foundation for more careful study of real-world effort allocation, through which incentives vary along several types (e.g., monetary, liquid, social) and dimensions (e.g., appetitive, aversive), and are seamlessly integrated (e.g., consideration of both monetary rewards and social praise (Park et al ., 2018; Crawford et al ., 2020)). Importantly, such insight into the neural mechanisms underpinning how motivational incentives are integrated to modulate effortful tasks can also provide a mechanistic framework that can advance understanding of how such mechanisms become maladaptive in clinical disorders associated with motivational or cognitive deficits.…”

A practical guide for studying human behavior in the lab

“…In our experience, a bonus up to 50-100% of the show-up fee is a good compromise. Alternatively, social incentives, such as the challenge to beat a previous score, can be effective in increasing the motivation of your subjects (Crawford et al, 2020) . If you plan to run an online experiment, be aware that your subjects might be more vulnerable to exploitation than subjects in your local participant pool (Semuels, 2018) .…”