Response Selection, Multitasking's Arch Enemy

During the last few weeks, I've shared several studies that suggest dual task performance--of both concurrent and switching varieties--can be improved through training, technology-based training specifically. I even wrote yesterday that I have accepted that conclusion as a fact. No sooner did I think that thought, than I stumbled upon a study describing a scenario in which training appears not to improve dual task performance. You might think I'd feel dismayed, but I'm actually pleased. You see, most of the studies I've shared so far have examined very low-level, unpractical examples of multitasking, and I haven't felt like they are sufficiently representative of complex, real-world, thought-demanding situations--"multitasking lite," so to speak. The study I will share today is very practical and sufficiently represents a complex, real-world, thought-demanding situation: Talking on a cell phone while driving.

The study, "Effects of Simulator Practice and Real-World Experience on Cell Phone-Related Driver Distraction," was conducted by Professor of Psychology David Strayer and his research assistant, Joel Cooper, at the University of Utah and published in the journal Human Factors in December of 2008. The study suggests that training does not improve one's ability to concurrently talk on the phone and drive. One of the strongest pieces of evidence in favor of their conclusion was that subjects who claimed to have extensive prior experience driving while talking on the phone performed equally as poorly as subjects who reported having little or no experience doing so. Another strong piece of evidence was that, after four days of training, the subjects did not demonstrate improved competency with talking on the phone while driving. Strayer and Cooper also observed that even when subjects practiced a driving scenario repeatedly (so all dangers were predictable), the only aspect of their driving that improved was crash avoidance, while all other factors--following distance, speed, and braking--remained unimproved; at the same time, when the subjects completed the scenario without talking on the phone, all factors did improve.

Strayer and Cooper conceded that the results of other experiments contradict theirs. They explained that the other experiments failed to mirror the unpredictable nature of driving in the real world. "(T)he findings (of other experiments) may not apply to less predictable aspects of driving, such as strategic vehicle control and response to sudden-onset events" (Strayer & Cooper, 2008, p 894). The reason those unpredictable events are important is because they require drivers to make rapid, thoughtful decisions. Decisions seem to be resistant to simultaneous processing, as Strayer and Cooper pointed out when they wrote, "Although driving and cell phone conversation are thought to be resource compatible (Horrey & Wickens, 2003), simultaneous task performance may be limited by the irascible central processing bottleneck thought to exist in response selection" (p 894). They accept the hypothesis that automatization of tasks through practice enables people to perform multiple tasks concurrently, but they believe making the decisions inherent in conversing and driving might not be automatizable.

One thing I learned from this study that was particularly enlightening is that "response selection" seems to limit the types of tasks capable of being performed concurrently. Now I wonder what other classes of tasks exist that are also resistant to concurrent performance. I think I am beginning to figure out how researchers could clinically tell the difference between dual task performance of the concurrent and switching varieties (but I'll not reveal my thoughts yet). Lastly, I hypothesize that rapid response selection is positively correlated with task switching efficiency. I wonder if there is any research related to my hypothesis.