Cohen, A. & Israel, M.
The Hebrew University, Department of Psychology, Jerusalem, Israel
Although it has been known for a long time that dual task performance is affected by strategic processes, research in recent decades focused on structural causes for dual task deficit. Consequently, dual task costs in paradigms such as the Psychological Refractory Period (PRP) paradigm have been attributed to structural causes. We present experiments that show that there exist powerful task-based strategic processes. Some such strategies are executed intentionally, but some strategies are triggered exogenously (i.e., without intention) and may cause costs even in situations where the two tasks could be performed without costs. We show that such exogenous strategies rather than structural reasons may lead to the PRP effect. We end with a discussion on the dual nature of strategic (flexible) processes that are performed exogenously (inflexibly).