Cognitive processes are often classified as either automatic or under attentional control. Automatic processes are an important component of ongoing behavior, because they free us from having to deliberate about every task that faces us. But this very automaticity creates a problem for many ongoing behaviors. Many of the stimuli we encounter and many of the tasks we face are ones in which an automatic process is not the one that is most appropriate to the present context. This is so for encoding, when attention is often drawn by salient stimuli in the environment that should not be the targets of processing. It is so for working memory, where we often have information stored that is irrelevant to the task at hand. And it is so for responding, when we often must overcome pre-potent responses to respond correctly in some situation. It is critical to understand how humans are able to overcome their automatic behaviors and engage in more controlled processing. For over 100 years, psychological experimentation and theory have grappled with understanding how interference is controlled and resolved in perceptual and memory tasks. For a time, the predominant view of interference-resolution rested on the assumption that there is a single mechanism responsible for inhibition of irrelevant or distracting information across a variety of circumstances. However, other research has led to the view that inhibitory mechanisms may vary from one task to another. How might the mechanisms of interference-resolution be similar to or different from task to task? That is the question that motivates the present application. With funding from the National Science Foundation, John Jonides is investigating two alternative dimensions to partition interference-resolution mechanisms. One rests on the proposal that different stages in the information-processing stream demand different mechanisms of interference-resolution. The hypothesis is being tested that encoding, maintenance in working memory, response selection, and response execution stages of processing have partially non-overlapping mechanisms that are engaged when there is interference that needs to be controlled. The second dimension concerns the type of information that is involved. There is evidence that verbal and spatial information are processed by different brain mechanisms in many tasks, and that interference may be resolved differently for the two types of information. The hypothesis will be tested that when there is verbal and spatial information involved in tasks for which interference must be controlled, different mechanisms are engaged.
The broader impacts of this research program will be felt in five areas. First, there will be a research seminar including graduate and undergraduate students that meets weekly to discuss ongoing research concerned with interference-resolution. Second, the research will be conducted with the participation of underrepresented students chosen from the Undergraduate Research Opportunity Program. Third, the research program will make use of an NSF-funded neuroimaging facility that will serve as a vehicle to educate students about neuroimaging methods. Fourth, the proposed research will result in published papers and conference presentations that will disseminate the empirical findings and document the development of the underlying theory. Finally, in that interference-resolution processes are critical to everyday cognitive functioning, the proposed program could lead to a prescription for training regimens that may strengthen some of these processes.
