Endogenous fluctuations in the dopaminergic midbrain drive behavioral choice variability

Area of Science:

• Neuroscience
• Cognitive Science
• Decision Science

Background:

• Human behavior exhibits significant variability, particularly in risky decision-making, which challenges existing economic theories.
• Previous research suggests endogenous brain activity fluctuations affect low-level processes, but their impact on high-level cognition like decision-making is unclear.

Purpose of the Study:

• To investigate whether endogenous fluctuations in brain activity influence complex cognitive processes, specifically risky decision-making in humans.
• To examine the role of the dopaminergic midbrain, including the ventral tegmental area and substantia nigra, in modulating risk-taking behavior.

Main Methods:

• Utilized real-time functional magnetic resonance imaging (fMRI) to monitor blood oxygenation level-dependent (BOLD) activity.
• Measured prestimulus BOLD activity in the dopaminergic midbrain during a risky decision-making task.
• Employed computational modeling to analyze the neural mechanisms underlying risk-taking behavior.

Main Results:

• Found that lower prestimulus brain activity in the dopaminergic midbrain was associated with an increased tendency towards risky choices.
• Computational modeling revealed that heightened risk-taking is mediated by amplified phasic responses to offers within the brain's decision network.

Conclusions:

• Endogenous fluctuations in brain activity, specifically in the dopaminergic midbrain, provide a physiological basis for variability in human risky decision-making.
• This study bridges the gap between neural activity and complex behavioral variability, offering new insights into decision-making processes.