The Cost of Accumulating Evidence in Perceptual Decision Making

Decision making often involves the accumulation of information over time, but acquiring information typically comes at a cost. Little is known about the cost incurred by animals and humans for acquiring additional information from sensory variables due, for instance, to attentional efforts. Through a novel integration of diffusion models and dynamic programming, we were able to estimate the cost of making additional observations per unit of time from two monkeys and six humans in a reaction time (RT) random-dot motion discrimination task. Surprisingly, we find that the cost is neither zero nor constant over time, but for the animals and humans features a brief period in which it is constant but increases…

• NS
  National Science Foundation

  Award: BCS0446730
• JS
  James S. McDonnell Foundation
• MU
  Multidisciplinary University Research Initiative

  Award: N00014-07-1-0937