The intrinsic cost of cognitive control: Behavioral Phenomenology and Neural Correlates

Abstract

Psychological theories have long maintained that tasks are chosen so as to minimize demands for cognitive exertion. This principle, known as the law of least mental effort, had, until recently, not been subjected to a direct test. However, a recent of studies has shown that people tend to avoid cognitive effort. The current work builds on this finding.

An initial set of experiments shows that demand avoidance does not merely reflect a tendency to maximize reward rate, or minimize the time needed to accurately reach task goals. In addition, they provide evidence for an important secondary prediction from the hypothesis that cognitive effort is associated with intrinsic disutility, namely that countervailing incentives increased the propensity to exert mental effort.

Daily life rarely offers a categorical choice between cognitive exertion and rest. Instead, most real life decisions involving effort are time-based, requiring an allocation decision between profitable but mentally demanding activities and activities that are undemanding but also unproductive. Results from four economic-choice experiments indicate that such decisions are guided by a motivation to strike an optimal balance between income and leisure, a principle derived from economic theories of labor supply.

Demands for cognitive control are ubiquitous in every day life, and therefore it is important to consider whether the intrinsic disutility of its exertion affects decisions studied in the broader field of psychological science. An individual difference experiment takes some of the first steps in this endeavor, probing a relationship between the avoidance of demands for mental effort and the capacity for self-controlled behavior.

Earlier research has revealed an important role for the prefrontal cortex in the registration of effort costs, but the role of neuromodulation in this process is less clear. We report a genotyping study that reveals a role for dopaminergic functioning in the representation of mental effort costs, analogous to findings in the animal literature on physical effort-based decision making.

This work reports initial progress in the understanding of the theoretical, behavioral, and neural implications for the intrinsic cost of cognitive control.