Poster F106, Tuesday, March 27, 8:00-10:00 am, Exhibit Hall C
The influence of expected reward and efficacy on cognitive effort allocation
Carolyn K. Dean Wolf1, Elizabeth V. Cory1, Amitai Shenhav1; 1Brown University
To achieve most high-level goals, people must utilize cognitive control. However, cognitive control is effortful, and individuals vary in their ability and/or desire to exert such cognitive effort. We have recently developed a computational model that describes how people decide how much cognitive effort to invest at a particular time (Shenhav et al., 2013). This model posits two key factors that are critical for deciding how much effort to invest in a task: (1) the reward one expects for succeeding at the task; (2) how likely they think they are to succeed given a particular level of cognitive effort (the perceived efficacy of that effort investment). Here we sought to validate these predictions by testing whether participants would change their level of cognitive effort depending on the expected levels of reward and efficacy, and to examine how people vary in their sensitivity to these two factors (which could provide insight into the basis of clinical impairments in motivation). Participants performed a Stroop task, and were cued on each trial with (1) the amount of reward available and (2) the degree to which reward attainment was determined by performance (efficacy). Across two studies, we find that participants exert more effort (measured by speed of correct responses) when reward is higher and when efficacy is higher. Importantly, we also find that participants’ sensitivity to reward is uncorrelated with their sensitivity to efficacy, consistent with the prediction that these two factors arise from separate mechanisms and might, therefore, separately contribute to motivational deficits.
Topic Area: THINKING: Decision making