Reward Circuit Local Field Potential Modulations Precede Risk Taking.

Area of Science:

• Neuroscience
• Computational Psychiatry
• Electrophysiology

Background:

• Risk-taking behavior is a common symptom in various neuropsychiatric disorders, yet effective treatments remain limited.
• Neuroimaging studies implicate reward circuitry regions (amygdala, orbitofrontal cortex, insula, anterior cingulate) in risk-taking, but electrophysiological underpinnings in humans are not well understood.

Approach:

• Stereotactic electroencephalography (SEEG) recorded local field potentials from epilepsy patients with electrodes in key reward circuitry regions during a gambling task.
• Cluster-based permutation testing identified reward prediction error signals and compared neural activity preceding high vs. low bets in high-risk trials.
• Linear mixed-effects models and regression analyses evaluated relationships between neural signals, reward prediction errors, and impulsivity scores.

Key Points:

• Reward prediction error signals were identified in the amygdala, anterior cingulate, and orbitofrontal cortex.
• Risky decisions were associated with increased oscillatory power in the orbitofrontal cortex, anterior cingulate, and insula.
• Risk-averse and optimized decisions showed distinct patterns of decreased oscillatory power in the orbitofrontal cortex, amygdala, and insula.

Conclusions:

• Electrophysiological activity in reward circuitry, particularly the orbitofrontal cortex and insula, is predictive of human risk-taking behavior.
• Neural signals related to reward prediction error and decision-making processes were characterized.
• These findings offer potential biomarkers for developing novel therapeutic strategies, such as closed-loop neuromodulation, for disorders involving aberrant risk-taking.