Many simple decisions allow us to trade o between speed and accuracy. When time is critical, decisions can be made quickly but accuracy su ers. Conversely, one may spend more time making a decision which often results in more accurate decisions. Speed-accuracy tradeo s have been studied in a number of domains including motor control (Fitts, 1954), perception (Usher & McClelland, 2001), and higher order reasoning (Kahneman & Frederick, 2002).

Recent research has examined a set of normative models for how one should trade o speed and accuracy (Bogacz, Brown, Moehlis, Holmes, & Cohen, 2006); that is, how long someone should spend deliberating prior to action in order to maximize some reward. However, empirical work has shown haphazard adherence to these normative models (e.g., Zacksenhouse, Bogacz, & Holmes, 2010). While some subjects behave optimally, many do not.

In two experiments, several factors that a ect speed-accuracy tradeo s in a perceptual decision-making task are investigated. In one experiment, it was found that feedback and shorter blocks not only improved participants’ task ability, but also resulted in more optimal speed-accuracy tradeo s. In a second experiment, manipulating trial di culty and subjects’ awareness of di culty level a ected task performance. However, despite predictions from a normative theory, participants did not engage in an optimal speed-accuracy tradeo policy.