Instructed delay activity in the human prefrontal cortex is modulated by monetary reward expectation

Area of Science:

• Neuroscience
• Cognitive Psychology
• Decision Science

Background:

• Goal-directed actions are more efficient when their outcomes are rewarded.
• Reward expectation is known to influence action planning and motor control.
• The neural mechanisms underlying reward's influence on action preparation in primates remain largely unknown.

Purpose of the Study:

• To investigate how reward expectation influences manual performance in humans.
• To identify the neural correlates of reward-modulated action preparation and selection using functional magnetic resonance imaging (fMRI).

Main Methods:

• Human subjects performed visually cued manual actions with monetary rewards.
• Event-related functional magnetic resonance imaging (fMRI) was employed to measure brain activity.
• Analysis focused on identifying brain regions showing interaction between reward value and action preparation.

Main Results:

• Manual performance was significantly enhanced when action goals were associated with monetary rewards.
• Three brain regions exhibited significant interaction between reward expectation and action preparation: prestriate visual cortex, premotor cortex, and lateral prefrontal cortex.
• The premotor and lateral prefrontal cortices were identified as key frontal systems integrating reward expectation with action selection and preparation.

Conclusions:

• Reward expectation plays a crucial role in enhancing the efficiency of goal-directed manual actions.
• Specific frontal brain regions, including the premotor and lateral prefrontal cortex, are critical for integrating reward information into action planning and motor control.
• This study provides novel insights into the neural basis of reward-guided behavior in humans.