‘Hands Free’ Is Not Brain Free
I’m slow to post on this, but I’ve finally gotten around to reading a new cell-phone driving study from the indefatigable David Strayer and colleagues from the University of Utah’s Applied Cognition Laboratory, via The Journal of Experimental Psychology: Applied.
With all the usual caveats (a small sample of student-aged drivers in a simulated driving environment), this study is of particular interest for addressing a question one often hears: How is talking on a phone while driving any different than talking to a passenger?
Among other things, test drivers were asked to exit a highway at a rest stop area under different conditions — while on the phone, while a passenger was present, etc. The researchers found that “drivers in the cell phone condition were four times more likely to fail task completion than drivers in the passenger condition.” (these were the socially sanctioned, but arguably no less distracting, ‘hands free’ phones, by the way).
They write: “On the strategic level of performance, cell phone drivers performed poorly at the navigation task. Two nonmutually exclusive explanations can be provided for this deficit: First, drivers conversing on a cell phone may experience problems with keeping the intention of exiting at the rest area in working memory, or second, drivers may not sufficiently process information from the driving environment (exit signs). Some support for the latter hypothesis comes from studies demonstrating inattention blindness in cell phone drivers (Strayer et al., 2003).”
What’s particularly interesting here is the way the conversation also changed with the cell-phone. Drivers made fewer references to traffic on the cell phone (because the person on the other end isn’t sharing the experience, or presumably interested in sharing it), and what’s more, actually started to speed up their conversation, even as it grew less multi-syllabic: “Also, quite surprisingly drivers conversing on the cell phone increased their production rate when talking on the cell phone, which is contrary to the predictions of the modulation hypothesis. More interesting, this happened even as those drivers in the passenger condition tended to reduce their production rate.”
The speech was getting simpler, in other words, even as it grew faster.
Drivers on cell phones, the author speculated, “may have attempted to dominate the conversation to avoid having to engage in speech comprehension, whereas with in-vehicle partners, it may be easier to relinquish control, given that the partner can be relied on to accommodate with his or her contributions.” (I’ve overheard quite a few cell-phone conversations where it seemed the caller was trying to dominate the conversation).
As study co-author Frank Drews told the Salt Lake City Tribune:
“It’s crazy. They talk faster. It’s quite counterproductive for driving safely,” Drews said. “There is an obviously malevolent influence.”
And, of course, it depends on who the passenger is: “For example a passenger who is too ‘supportive’ by constantly commenting and directing attention in an overcontrolling fashion has a potentially negative impact on performance.” (what I call the ‘Hyacinth Bucket syndrome’).
See the video here.
This entry was posted on Thursday, December 4th, 2008 at 4:33 pm and is filed under Drivers, Traffic Psychology, Uncategorized. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.