Fluctuations in the Time Required for Elementary Decisions

Abstract

The nature of reaction time variability is analyzed in a suite of four experiments involving tasks, methodologies, and types of perceptual judgment commonly encountered in cognitive psychology In every case, a substantial fraction of the trial-by-trial variability in reaction time latency is shown to be well described by a particular type of fluctuation known as IA noise These results suggest that the time it takes to make and register a speeded decision reflects a kind of dynamic complexity that is seen in natural systems that self-organize at the boundary between order and chaos.