Eye movements reveal dynamics of task control.

With the goal to determine the cognitive architecture that underlies flexible changes of control settings, we assessed within-trial and across-trial dynamics of attentional selection by tracking of eye movements in the context of a cued task-switching paradigm. Within-trial dynamics revealed a switch-induced, discrete delay in onset of task-congruent fixations, a result that is consistent with a higher level configuration process. Next, we derived predictions about the trial-to-trial dynamic coupling of control settings from competing models, assuming that control is achieved either through task-level competition or through higher level configuration processes. Empirical coupling dynamics between trial n-1 eye movements and trial n response times--estimated through mixed linear modeling--revealed a pattern that was consistent with the higher level configuration model. The results indicate that a combination of eye movement data and mixed modeling methods can yield new constraints on models of flexible control. This general approach can be useful in any domain in which theoretical progress depends on high-resolution information about dynamic relationships within individuals.