Noninvasive Brain Stimulation over the Frontopolar Cortex Promotes Willingness to Exert Cognitive Effort in a...

Area of Science:

• Neuroscience
• Cognitive Psychology
• Decision Science

Background:

• Cognitive effort is avoided unless rewards justify costs.
• Frontopolar cortex (FPC) involvement in effort-based decision-making is suggested by prior research.
• The role of FPC in motivating effort needs examination in complex, sequential choices.

Purpose of the Study:

• To investigate if the FPC's role in effort motivation extends to sequential decision-making with variable task demands and rewards.
• To explore the causal involvement of the FPC in effort-based choices using transcranial direct current stimulation (tDCS).

Main Methods:

• A double-blind, within-subject design with 46 participants.
• Anodal or sham tDCS applied to the right FPC during an Effort Foraging Task.
• The task involved choices between resource harvesting and cognitive effort for rewards, with environment-specific difficulty.

Main Results:

• Participants showed higher exit thresholds (stayed longer in patches) when travel effort was high, indicating increased perceived travel costs.
• Anodal tDCS to the FPC significantly reduced the difference in exit thresholds between high- and low-effort environments compared to sham stimulation.
• Individual differences revealed that reduced motivation correlated with greater travel cost reduction under tDCS.

Conclusions:

• Findings support the FPC's causal role in motivating cognitively effortful behavior.
• The FPC's function extends to ecologically valid, serial decision-making scenarios.
• tDCS targeting the FPC shows potential for enhancing motivation, with possible clinical applications.