One Brain's journey

With the new mobile phone law coming into effect in Ontario (many jurisdictions in North America already have similar laws in force) distractions while fiddling with the phones should be severely reduced but a new study shows that most of the distraction is still present while using hands-free devices.  The problem has to do with working memory or rather the way it works talking to someone in the car versus someone who is not.  There have been a number of studies to show you can be just as distracted while holding a mobile phone as you are using a hands-free device but a new study speculates on why this is so. Working memory may be quite taxed in a conversation and some of it needs to be freed up to cope with an emergency situation such as a road hazard.  Working memory is one aspect of the human brain that has a limit on how well it will work and an earlier post on this blog suggests this is somewhere between seven and nine items–such as numbers, words or visual relationships for everyone.  The study used a driving simulator while the test subjects held conversations with passengers who were in the car and with others who were not.  Those who had conversations with others who were not in the car demonstrated slow reaction times in speed of braking responses and hazard avoidance.  What the researchers found was that when the other party was in the car they demonstrated “conversation suppression”.  In other words their speech slowed down in reaction to hazards they could see being in the car with the driver and this allowed the driver to free up working memory and shift focus to the road.  Of course other parties in conversations with the driver who were not in the car demonstrated no such conversation suppression because they could not see the hazards.  As an end-note the researchers say that talking to an in-car passenger might actually improve driver performance because both parties are able to see any hazard on the road that might present itself and the passenger can provide a verbal warning to the driver and even point to the hazard focusing the driver even more.