Dorsolateral prefrontal cortex plays causal role in probability weighting during risky choice

Abstract

In this study, we provide causal evidence that the dorsolateral prefrontal cortex (DLPFC) supports the computation of subjective value in choices under risk via its involvement in probability weighting. Following offline continuous theta-burst transcranial magnetic stimulation (cTBS) of the DLPFC subjects (N = 30, mean age 23.6, 56% females) completed a computerized task consisting of 96 binary lottery choice questions presented in random order. Using the hierarchical Bayesian modeling approach, we then estimated the structural parameters of risk preferences (the degree of risk aversion and the curvature of the probability weighting function) and analyzed the obtained posterior distributions to determine the effect of stimulation on model parameters. On a behavioral level, temporary downregulation of the left DLPFC excitability through cTBS decreased the likelihood of choosing an option with higher expected reward while the probability of choosing a riskier lottery did not significantly change. Modeling the stimulation effects on risk preference parameters showed anecdotal evidence as assessed by Bayes factors that probability weighting parameter increased after the left DLPFC TMS compared to sham.

A Causal Role of the Right Dorsolateral Prefrontal Cortex in Random Exploration

“…At first glance, these studies seem at odds with our observation. However, the effect of cTBS in risk-taking behavior and increasing dopamine release seems to be limited to the left DLPFC (and not the right DLPFC) [Ko et al, 2008, Ott et al, 2011, Panidi et al, 2022]. A recent meta-analysis of fMRI studies related to exploration-exploitation-related tasks (e.g., armed bandit and foraging tasks) showed that rDLPFC activation is specific for exploration and not risk [Zhen et al, 2022].…”

Posterior parietal cortex is causally involved in reward valuation but not probability weighting during risky choice

“…The experimental protocol closely follows the one used in a previous TMS study on the role of the DLPFC in risky choice (Panidi et al, 2022). The experimental task consisted of 85 selfpaced binary lottery choice questions.…”

Motor Decision-Making as a Common Denominator in Motor Pathology and a Possible Rehabilitation Target

“…According to the results of invasive animal studies, a number of areas critical for movement preparation and execution are also encoding MDM parameters. 10,52-55 Recently it has been suggested that prefrontal cortical areas such as DLPFC, responsible for goal valuation during decision-making under risk, 56 also modulates motor output, speeding up movement execution. 57 Some evidence suggests the orbitofrontal cortex involvement in encoding values for the movements’ endpoints.…”