The medial prefrontal cortex exhibits money illusion

Area of Science:

• Neuroscience
• Behavioral Economics
• Cognitive Science

Background:

• Standard economic theory assumes rationality, where individuals evaluate money based on its real value (purchasing power).
• Behavioral economics proposes 'money illusion,' a deviation where nominal value influences decisions, explaining economic phenomena.
• This study investigates the neural basis of money illusion within the brain's reward system.

Purpose of the Study:

• To investigate whether the brain's reward circuitry exhibits money illusion using functional magnetic resonance imaging (fMRI).
• To determine if neural activity in reward-related areas differs when monetary rewards are identical in real terms but differ in nominal terms.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was employed to measure brain activity.
• Participants were presented with monetary prizes under two experimental conditions with identical real economic value but differing nominal values.
• Brain activation in reward circuitry was compared between the two conditions.

Main Results:

• The ventromedial prefrontal cortex (vmPFC), associated with reward processing and valuation, showed significant activation differences consistent with money illusion.
• These vmPFC activation patterns directly correlated with the degree of money illusion observed in participants' economic evaluations.
• This suggests a neural basis for the deviation from purely rational economic decision-making.

Conclusions:

• The brain's reward circuitry, specifically the vmPFC, demonstrates money illusion.
• This neural evidence supports the behavioral economic concept that nominal value influences decision-making beyond real economic worth.
• Money illusion has a demonstrable neurological foundation affecting economic valuation and behavior.