Neurocomputational mechanisms underlying subjective valuation of effort costs

Abstract

In everyday life, we have to decide whether it is worth exerting effort to obtain rewards. Effort can be experienced in different domains, with some tasks requiring significant cognitive demand and others being more physically effortful. The motivation to exert effort for reward is highly subjective and varies considerably across the different domains of behaviour. However, very little is known about the computational or neural basis of how different effort costs are subjectively weighed against rewards. Is there a common, domain-general system of brain areas that evaluates all costs and benefits? Here, we used computational modelling and functional magnetic resonance imaging (fMRI) to examine the mechanisms underlying value processing in both the cognitive and physical domains. Participants were trained on two novel tasks that parametrically varied either cognitive or physical effort. During fMRI, participants indicated their preferences between a fixed low-effort/low-reward option and a variable higher-effort/higher-reward offer for each effort domain. Critically, reward devaluation by both cognitive and physical effort was subserved by a common network of areas, including the dorsomedial and dorsolateral prefrontal cortex, the intraparietal sulcus, and the anterior insula. Activity within these domain-general areas also covaried negatively with reward and positively with effort, suggesting an integration of these parameters within these areas. Additionally, the amygdala appeared to play a unique, domain-specific role in processing the value of rewards associated with cognitive effort. These results are the first to reveal the neurocomputational mechanisms underlying subjective cost–benefit valuation across different domains of effort and provide insight into the multidimensional nature of motivation.

Effect of acute modafinil ingestion on cognitive and physical performance following mental exertion

“…For most participants, modafinil appeared to facilitate endurance performance. Mechanistically, this could be through altering the neuromodulatory environment related to effort and motivationally based behaviour (e.g., see Minzenberg & Carter, 2008), consistent with enhancing cognitive control processes (e.g., see Chong et al, 2017;Esposito et al, 2013) as has been previously proposed (Battleday & Brem, 2015). However, overall, we did not find significant results.…”

“…Modafinil may improve performance normally inhibited with mental fatigue thorough enhancement of cognitive control processes (see Battleday & Brem, 2015). Modafinil alters activation of front-parietal control and dorsal attentional networks (Cera, Tartaro, & Sensi, 2014;Esposito et al, 2013) implicated in the cognitive processes that coordinate the pursuit of a goal (e.g., Chong et al, 2017).…”

The Effort Paradox: Effort Is Both Costly and Valued

“…Another indication that effort is costly comes from the finding that people are often willing to accept fewer rewards to avoid effort [61,62]. That is, just as people discount rewards by their associated delays [63,64], so too do they discount rewards by the amount of cognitive or physical effort required to obtain them (i.e., effort discounting ) [21,65]. …”

Decision-Making Measured by the Iowa Gambling Task in Patients with Alcohol Use Disorders Choosing Harm Reduction versus Relapse Prevention Program

“…Of course, decision-making is linked to cognitive processes, but in a recent study, Verdejo-Garcia et al [6] showed that decisions could be impaired with preserved executive functions. To make a choice between different options, the value of each option is examined, subserved by different areas [8]. Compared to controls, alcoholics had widespread reduced gray matter volume in the ventromedial prefrontal cortex, dorsal anterior cingulate and right hippocampal formation [9,10].…”