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    Cell Phones, Driving, And Multitasking
    By Michael W. Taft | December 31st 2011 08:33 AM | 6 comments | Print | E-mail | Track Comments
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    Michael W. Taft is a student of evolution, psychology, and the capacities of the human brain. A professional researcher and writer for more than...

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    This December the National Transportation Safety Board of the U.S. recommended a nationwide ban on cell phone use while driving. According to NTSB member Robert Sumwalt, "This (distracted driving) is becoming the new DUI. It's becoming epidemic.” For some, the NTSB recommendation is a sign of the forces of light winning the day, and for others, proof of the impending apocalypse. Regardless of your emotional reaction to the issue, the subject cuts right to the heart of questions about the attention capacity of the human brain.
     The essence of the NTSB’s problem with cell phones is that they are too distracting. Studies show that talking while using a hands-free headset is just as likely to cause accidents as talking without a headset. Human brains appear to be optimized to focus on one thing at a time. While it is, of course, possible to attend to two or more things simultaneously, we do neither task at the level of quality that is possible if it we were to do it on its own. fMRI scans show that learning while multitasking engages different areas of the brain than learning while single-tasking. 

    The human brain does not do as well under multitasking situations, and driving while talking on the cell phone involves a particularly difficult sort of multitasking: doing a visual task (like driving) and doing an auditory task (like talking on the phone) at the same time. This sort of multitasking requires the use of two separate brain regions simultaneously. And a 2001 study by Marcel Just at Carnegie Mellon showed that when volunteers did one task at a time, they used 37 voxels (small brain regions), but when they did both a visual and an auditory task simultaneously, they only used 42 voxels—far less than double. The brain has only so much processing capacity, and adding new tasks bogs all of them down. As Just commented, “You can't just keep piping new things through, and expect the brain to keep up. With practice, the brain can become more efficient at carrying out multiple tasks, but performance is never as good as when the tasks are carried out independently.” 

    But is talking on a cell phone fundamentally worse or different from talking to another passenger? At least a conversational passenger is also scanning the road and could help alert drivers to oncoming dangers—something a cell phone conversant can never do. There are plenty of other distractions to driving: children, radios, eating, even shaving or doing makeup. Though traffic fatalities are at their lowest point since 1949 (thanks to improved safety features, more seat belt usage, and safer roads), the threat of distracted driving still worries many policymakers in the wake of incidents like the Chatsworth Train Disaster, in which the engineer was texting while driving. And as more and more gadgets become available as possible sources of distraction, the level of distractedness across the board may be rising.

    In his famous definition of attention, William James noted that it “...implies withdrawal from some things in order to deal effectively with others, and is a condition which has a real opposite in the confused, dazed, scatterbrained state" (1). It appears that today human attention is at an all-time premium, yet few of us seem to have enough to go around. The brain evolved under conditions that were almost certainly far less stimulating, and we’ve created an artificial environment where the intensity, duration, and variety of stimulation is beginning to tax the upper limits of normal attention. This may have some very interesting consequences in the near future, from bans on the use of some technologies (a la the NTSB stance or the cell phone ban in many schools), to the use of attention-boosting drugs such as Modafinil, to the proliferation of attention training techniques like mindfulness practice. Or we may just learn to turn the gadgets off when needed, just as we have learned as a culture that it’s not a good idea to drink and drive.


     1. James, William. Principles of Psychology. 1890. p.403

    Comments

    SynapticNulship
    Sometimes I wonder if we are at that awkward historical stage of growing where the new tech has temporarily caused an increased demand on humans--and increased risk of messing up. Hopefully in a few years the driver assist and partial autonomy functions, etc. will be more widespread and the interfaces will have improved from a human factors point of view.

    I don't think we should try to go backwards to the old way of driving because it sucks--if you are stuck in traffic, or even waiting at a stop light for 1 minute (which aggregates into several minutes in a single commute) then you very well should want to amuse yourself and/or do some work.
    Gerhard Adam
    The problem here isn't multi-tasking nor the failure to multi-task effectively.  The problem is poor choices in managing priorities.  An airplane pilot (private pilot) has to talk on a radio, navigate, and watch for other traffic (and other hazards potentially).  So the skill of cockpit management is important.

    However, every pilot will tell you that the PRIORITY rule is "first, fly the airplane".  Similarly, if such a rule were emphasized for automobile drivers, I suspect we'd have fewer problems.  Therefore, it seems to me that most accidents are caused because the driver thinks "it can't happen to them", rather than anything else.  It isn't that distractions occur.  It's that we allow such distractions to take us away from our priority task of driving the car.
    Mundus vult decipi
    Halliday
    It's been quite a while, but I recall seeing studies that actually compared cellphone use, while driving, to driving while intoxicated, and/or to impairment with age.  The conclusions, in all cases, were that driving while using a phone, even hands-free, was very comparable to the other impairments.

    As a couple of anecdotes:  1)  I was in a (near) head-on collision with a driver that barrelled through an intersection, where all the other cars were stopped, because he was talking on a cellphone, and said he "never saw".  2) Additionally, I have been behind many a driver that drove well below the speed limit, swerved, and otherwise appeared "drunk", only to find they were talking on a cellphone.

    Not only is there a difference in talking to a passenger while driving due to the passenger also "scanning the road and could help alert drivers to oncoming dangers", but such a "conversational passenger" will recognize and be supportive of the driver taking their attention off the conversation in order to handle the "rigors of the road".  My suspicion is that many drivers who are on cellphones are "afraid" of "offending" the person they are talking to, and, therefore, don't "leave" the conversation as often as they should.

    David
    Hank
    National Geographic did a TV show on the brain a short while back ("Brain Games") where they put a legendary multitasker in a simulator with only a very mild level of distraction while driving.  Hilarity ensued. As neuroscientists know, we don't really multitask, we just switch between tasks and we think we do it well.
    I think banning cell phones didn't make a difference because Bluetooth is equally distracting. It's not the fact of holding the phone; it's the fact that someone using Bluetooth is still mentally distracted and engrossed in conversation and not on driving. That's the real problem.

    There is a big chance of having an accident while using a cell phone while driving. Many accidents have been reported related to this situation. If we can avoid using a cell phone while driving that could be better. Prevention is better than cure.