The neural mechanisms of fast versus slow decision-making

Abstract

Is more haste less speed? Decision time variability has been attributed to speed/accuracy trade-offs(1), internal mental architecture(2), and noisy evidence accumulation(3-5). However, exploring these possibilities is difficult in rodents that consistently behave impulsively. Here, we demonstrate a novel floating-platform system that allows head-fixed mice to voluntarily vary decision times, akin to observed human behavior, in combination with sensitive neuroimaging approaches. We track the activity flow from medial to lateral frontal cortex (MFC to LFC) and record sequences of single-neuron activity. Choice-selective neurons displayed divergent temporal codes between MFC and LFC, with remarkable MFC susceptibility to optogenetic inhibition. These results suggest that LFC acts as an integrative motor threshold, while MFC plays a broader cognitive role in strategy and choice-selection.