The computational and neural substrates of individual differences in impulsivity under loss framework

Area of Science:

• Neuroscience
• Cognitive Psychology
• Decision Science

Background:

• Individual differences in intertemporal choice are often linked to reward circuits, cognitive control, and prospection.
• Previous research on impulsivity mechanisms has largely focused on gains, neglecting the loss domain.

Purpose of the Study:

• To investigate the computational neural substrates of impulsivity within the loss domain.
• To extend the understanding of intertemporal choice mechanisms beyond the gain domain.

Main Methods:

• Utilized a hierarchical Bayesian drift-diffusion model (DDM) and inter-subject representational similarity analysis (IS-RSA).
• Employed a revised intertemporal task manipulating immediate versus delayed loss options across two experiments (N=155).

Main Results:

• Behavioral data showed a positive correlation between DDM drift rate and impulsivity index K, replicated across experiments.
• Neuroimaging revealed that drift rate mediated the relationship between prefrontal cortex/orbitofrontal cortex/precuneus brain properties and impulsivity.
• IS-RSA indicated drift rate variability mediates associations between neural activation patterns and individual differences in impulsivity.

Conclusions:

• Neural mechanisms, particularly drift rate, underlie individual differences in impulsivity within the loss domain.
• Similar impulsivity levels correlate with similar value processing patterns, offering a framework for understanding loss-related decision-making.