What if you are not certain? A common computation underlying action selection, reaction time and confidence judgment

Abstract

From what to wear to a friends party, to whether to stay in academia or pursue a career in industry, nearly all of our decisions are accompanied by a degree of confidence that provides an assessment of the expected outcome. Although significant progress has been made in understanding the computations underlying confidence judgment, the preponderance of studies focuses on perceptual decisions, in which individuals sequentially sample noisy information and accumulate it as evidence until a threshold is exceeded. Once a decision is made, they initiate an action to implement the choice. However, we often have to make decisions during ongoing actions in dynamic environments where the value and the availability of the alternative options can change with time and previous actions. The current study aims to decipher the computations underlying confidence judgment in action decisions that are made in a dynamic environment. Using a reaching task in which movements are initiated to multiple potential targets, we show that action selection, reaction time and choice confidence all emerge from a common computation in which parallel prepared actions compete based on the overall desirability of targets and action plans.