Separate and overlapping brain areas encode subjective value during delay and effort discounting.

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Decision Science

Background:

• Decision-making under uncertainty involves integrating reward value with costs like delay or effort.
• Neural mechanisms for delay discounting are well-studied, but less is known about integrating cognitive effort costs.
• Previous research primarily focused on physical effort, leaving cognitive effort integration under-explored.

Purpose of the Study:

• To investigate how the brain integrates cognitive effort costs into value signals for decision-making.
• To identify brain regions involved in discounting rewards based on cognitive effort.
• To compare neural representations of effort discounting with delay discounting.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used to monitor brain activity.
• Participants performed a task involving discounting the value of delayed and effortful rewards.
• Analysis focused on identifying brain regions representing reward value and chosen options under different cost conditions.

Main Results:

• The anterior inferior frontal gyrus and dorsolateral prefrontal cortex encoded the value of cognitively effortful rewards.
• The anterior cingulate cortex (ACC), caudate, and cerebellum encoded the value of the chosen option.
• The ACC showed significantly greater activation during effort discounting compared to delay discounting.
• Overlapping regions in the orbitofrontal cortex, temporal, and parietal cortices encoded chosen value in both conditions.

Conclusions:

• Encoding of rewards discounted by cognitive effort and delay involves partially distinct brain areas.
• Common neural representations for chosen value exist in the orbitofrontal, temporal, and parietal cortices.
• These findings elucidate the neural basis of integrating cognitive effort into value-based decision-making.