Neuronal population biomarkers of temporal difference learning in human impulsive choices

Impulsive choice is a facet of impulsivity that may lead to one to choose smaller, more immediate rewards over larger, delayed rewards. Impulsive choice is a kind of maladaptive decision making that is a fundamental element of relapse in substance use disorder. Despite its essential role in relapse, there is currently little understanding of the neural basis of impulsive choices. Better understanding of the neural correlates of impulsivity could lead to improved diagnosis and treatment of psychiatric disorders in which impulsive choice plays a role. In this work, we examined impulsive choice behavior in humans undergoing intracranial seizure monitoring by fitting temporal difference learning models to behavior and broadband high frequency (70–150 Hz) local field potentials. We found neural and behavioral differences between more and less impulsive choosers, informing the neural underpinnings of impulsive choices and describing a biomarker for reward expectation and surprise in the human brain.