Modulation of ventral striatal activity by cognitive effort

Area of Science:

• Neuroscience
• Cognitive Psychology
• Decision Science

Background:

• Effort discounting theory posits decreased reward value with increased effort.
• Contrast theory suggests increased reward value due to the effort-reward contrast.

Purpose of the Study:

• To investigate the neural mechanisms underlying reward valuation under varying cognitive effort levels.
• To differentiate between effort discounting and contrast theory predictions using fMRI.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was employed.
• Participants undertook a feedback-based learning task with manipulated cognitive effort (low vs. high).
• Ventral striatum activity was analyzed in relation to positive feedback acquisition.

Main Results:

• Cognitive effort significantly impacted task accuracy and perceived difficulty.
• Ventral striatum activation increased with higher cognitive effort for positive feedback.
• Results align with contrast theory, showing enhanced reward signaling for effortful gains.

Conclusions:

• Cognitive effort amplifies reward-related neural activity in the ventral striatum.
• Contrast theory provides a better framework for understanding effort-based reward valuation.
• Hard-earned intrinsic rewards may particularly enhance brain activity associated with reward.