Dialing for Dullards

We do this exercise during our unit about perception. It springs from David Myers’s adaptation of Rozin and Jonides’s classic demonstration of the nature of neural connections in the brain, which we did during an earlier unit.

In that exercise, students stand up, form a line, and place their arms on the shoulders of the person in front of them. The professor stands at the back of the line and unobtrusively squeezes a shoulder of the next person. As quickly as possible, that student then squeezes a shoulder of the following student, and so on. The instructor times how long it takes to get from one end of the line to the other. Variations can illustrate the strengthening of neural connections through practice or the effect of increasingly complex information processing.

During the perception unit, students are assigned several brief articles reporting on research showing that cell phone use significantly impairs one’s attention while driving. It occurred to me that I could adapt the exercise to actively illustrate that effect, which ought to be more effective than simply discussing it in class.

I briefly mention the cell phone research and how at 68 mph an attention-related delay in reaction time of even a tenth of a second increases stopping distance by 10 feet. After the inevitable comments and discussion, I propose that we do our own research, using a variation of the shoulder-squeezing method.

I ask for volunteers to arrange for a friend or family member to be available for a phone conversation at a specified time during our next class session. If some students want to participate but have no one available to call, I pair them up to call each other. Most of my students carry cell phones, and most are eager to participate, so I’ve never had any difficulty obtaining sufficient volunteers, even in a small class section.

Next class, a minute or two before the designated time, the participating students do two or three nontalking run-throughs, for a baseline measure and to minimize any practice effect. For this part, students keep both hands on their lap, holding the phone in their preferred hand. I start the shoulder squeeze, then when a student feels his or her shoulder get squeezed, the student squeezes the next shoulder using the nonphone hand (e.g., left hand squeezes left shoulder). I tell them that this is exactly what they’ll be doing again, except this time they’ll be talking on the phone.

Students then call their talking partners and start conversing. As before, the nonphone hand is kept in the lap. (Noncallers usually are amused by the spectacle. I also ask them for their observations later on.) After two to three minutes, I do the first squeeze and time the process as usual. (I had one occasion in which an extraordinarily absorbed student didn’t even notice her shoulder being squeezed. We discussed that later, of course, but I did need to start the timing again.)

After we evaluate the inevitable results we discuss what exactly it might be about cell phone use that could account for the additional processing time.

In a larger class, one could extend the study’s design by having a two other groups, each with different students — one doing the reaction time tests while talking on a headset (e.g., a Bluetooth) and the other sitting next to and conversing with a “passenger” rather than talking on a cell phone.