Executive control of visual attention in dual-task situations

A theory of executive control is presented that proposes that executive pro cesses control subordinate processes by manipulating their parameters, reco nfiguring them to respond in accord with the current task set. It adopts C. Bundesen's (1990) theory of visual attention (TVA) and R. M. Nosofsky and T. J. Palmeri's (1997) exemplar-based random walk (EBRW) as the theory of s ubordinate processes. It assumes that a task set is a set of TVA and EBRW p arameters sufficient to perform a task and that set switching involves chan ging those parameters. The theory solves 2 computational problems that emer ge in dual-task situations: the binding problem and the serial order proble m. It can perform dual tasks in series or in parallel but prefers the seria l strategy because it is faster and it solves the binding problem naturally . The theory accounts for concurrence cost, set-switching cost, crosstalk b etween tasks, and the modulation of crosstalk by task set.