Rational Analysis in Task Switching
Michael Schwemmer (Mathematical Biosciences Institute, The Ohio State University)
(October 11, 2012 10:20 AM - 11:15 AM)
Task switching has been used as an experimental index of limitations on human cognitive flexibility. When switching from one task to another, participants exhibit increased reaction time, even when given ample time to prepare for the switch. Classical explanations of this "residual switch cost" typically presuppose that participants are fully motivated to perform the experimental task. This leads to interpretations of the residual switch cost in terms of structural cognitive factors. More recently, alternative explanations have proposed a role for motivational factors, arguing that preparation for task switches requires effort that participants are typically unwilling to expend, leading to only partial preparation (and residual switch costs) on average. In order to formalize the competing motivational and structural hypotheses of the residual switch cost into two alternative models, we employ a formal rational analysis of task switching experiments. This analysis shows that it is difficult to adjudicate between motivation and structural interpretations given existing data. We then conduct two new experiments to more conclusively test these ideas. Both experiments provide evidence for motivation-insensitive preparatory processes. Overall, this work casts doubt on the motivational interpretations of the residual switch cost, and provides a rigorous and principled framework for specifying and testing future hypotheses about motivational effects in the task switching paradigm.