Worth working for: The influence of effort costs on teens' choices during a novel decision making game

Abstract

Decision making requires consideration of both the benefits of a given choice and the costs, which can include risk, delay, and effort. Previous research has examined the developmental trajectory of adolescent decision making regarding risk and delay; however, the effects of effort on adolescent decision making remain largely unexplored. In the present study, we pilot tested a novel, developmentally-appropriate task designed to examine developmental differences in the willingness to expend effort during goal pursuit in adolescents (ages 13-16, n = 23) versus young adults (ages 18-23, n = 25). Self-reported reward responsivity correlated with task-related parameter estimates for effort and reward, providing evidence of task validity. Adolescents exhibited reduced sensitivity to physical effort costs compared to adults, effects which did not appear to be driven by differences in subjective task motivation or awareness of the effort requirements. These findings provide preliminary evidence that adolescence may be a time of increased willingness to expend effort during goal pursuit. Effort-based decision making is an understudied but exciting avenue for developmental research, as the willingness to engage in effortful pursuit of new experiences during adolescence may help to facilitate the path to independence.

Keywords: Adolescence; Adolescent; Cost-benefit; Decision making; Development; Dual systems; Effort; Effort-based decision making; Effort-discounting; Effortful; Goal pursuit; Motivation; Physical effort; Reward; Reward response; Young adult.

Copyright © 2019 The Authors. Published by Elsevier Ltd.. All rights reserved.

Figures

Fig. 1

Blaster properties. Conditions were counterbalanced across colors. Increasing effort was required to attain greater reward, such that low effort was always paired with low reward, medium effort with low or medium reward, high effort with medium or high reward, and extreme effort only with high reward.

Fig. 2

Task Schematic for Choice Trials. Participants completed five blocks of trials, in which they pressed “1” or “2” to pick up a blaster and pressed “x” rapidly to charge each blaster (A). During choice blocks (14 trials/block), trials presented an opportunity to choose between two blasters. The time limit for charging was individually calibrated based on performance during a pre-task calibration phase: time limit = r(pt)(1.1) + (rt)(1.1), where r = current number of press repetitions required, pt = average press rate during calibration, and rt = average response latency to begin charging during calibration. After participants successfully charged a blaster (B), they saw a feedback screen showing 1, 2, or 3 “blasted” aliens with an “x” on their foreheads, paired with the sound of one, two, or three blaster sounds, as well as “+1,” “+2,” or “+3″ to indicate the reward level (C, top). When they did not succeed, they saw an image of three aliens teasing them with tongues stuck out (C, bottom).

Fig. 3

Perceived Effort Category Rating for each Effort Level. Post-task ratings of perceived blaster effort category indicated that participants in both age groups were able to accurately differentiate between blasters from different effort categories.

Fig. 4

Effect of Effort on Adjusted Preferences. Adjusted preferences represent the degree to which game play increased participants’ preferences for each blaster. Whereas adults consistently preferred the relatively lower-effort options (shown in purple with dashed lines) compared to the relatively higher-effort (shown in green with solid lines), adolescents only differentiated between high and extreme effort levels, which were associated with the highest level of reward. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article).