Modeling response time with power-law distributions

Abstract: Understanding the properties of response time distributions is a long-standing problem in cognitive science. We provide a tutorial overview of several contemporary models that assume power law scaling is a plausible description of the skewed heavy tails that are typically expressed in response time distributions. We discuss several properties and markers of these distribution functions that have implications for cognitive and neurophysiological organization supporting a given cognitive activity. We illustrate how a power law assumption suggests that collecting larger samples, and combining individual subjects' data into a single set for a distribution-function analysis allows for a better comparison of a group of interest to a control group. We demonstrate our techniques in contrasts of response time measurements of children with and without dyslexia.