To better understand the interactions between concurrently performed tasks, my lab is investigating the role that working memory (WM) plays in response selection and whether it accounts for the fact that overlap in the stimulus-response mappings across the tasks rather than task difficulty appears to drive dual-task costs after practice.  A key assumption is that making the appropriate response to a stimulus engages the same processes as retrieving an item in a WM task.  This assumption has been suggested by other theorists, but the implications for skill acquisition in general and response selection in particular have not been explored.  Specifically, we propose that, after practice, dual-task performance primarily reflects the ability to simultaneously retrieve items from WM.   Whether it is possible to retrieve multiple items in WM at the same time has become an active topic in the memory literature.  Thus, this research has the potential of bridging two separate literatures.

To directly test this proposal, we are conducting a series of experiments combining a response selection task and a WM task.  The logic of these experiments is akin to earlier work examining whether WM consists of separate modality-specific subsystems.  However, the present experiments isolate the components of the response selection task that interfere with different types of information in WM.  We independently manipulate the stimuli and responses in the choice reaction time task, along with the type of information in the WM task.  The results indicate that response selection interferes with maintenance in WM, depending on the stimuli and responses of the choice reaction time task, and the type of information to be held in WM.  Thus, we have initial evidence that response selection processes do engage WM (Hazeltine & Wifall, 2011).

Representative Papers