Activation patterns of the dorsal medial prefrontal cortex and frontal pole predict individual differences in decision impulsivity.

ABSTRACT

Intertemporal choice refers to decisions that need to weigh different rewards at different time points in the future. Decision impulsivity manifests in the tendency of choosing smaller immediate options rather than larger later ones. Previous studies have suggested that decision impulsivity in intertemporal decision-making shares similar cognitive and neural mechanisms with risky decision-making. The present study theorizes on and examines whether the activation patterns of the dorsal medial prefrontal cortex (DMPFC) and the frontal pole (FP) during the risk-taking "cups task", as captured in the scanner, can predict the delay discounting rate (k) based on an intertemporal decision task performed outside the scanner. To this end, we scanned with functional magnetic resonance imaging (fMRI) techniques a sample of 257 college students (N = 257) while performing the cups task. Univariate analyses showed that activation levels of the DMPFC and the FP were inversely correlated with risk preference, but not with the delay discounting rate k. Multivariate pattern analysis, which can overcome key limitations of the univariate analyses, showed that activation patterns of these two regions predict the delay discounting rate k. These results confirmed the important roles of DMPFC and FP in decision impulsivity and the utility of using multivariate pattern analysis with fMRI data involving decision making tasks.