The Brain-Road Link: New Evidence on Cell Phones and Driving

Neuroscience_Neurology2.jpgLaw enforcers now have all the proof they need for tougher anti-cell phone measures for drivers, as the latest published neurological study shows that there is a 37% reduction in parietal cortex activity with driving. Arguments that there are many among us who can multi-task well have taken a back seat in recent studies involving driving and mobile phone listening.

An University of Oregon Study in 2005 found that complex skills like driving do not only include motor skills, but also staying receptive of visual and spatial cues from minute to minute. It estimated that conversing on the cell phone can increase a driver’s response time by up to 800 milliseconds, and at 60 miles per hour that could mean a significantly higher risk to drivers responding to road hazards.

This new study from Carnegie Mellon, reported in a recent issue of Brain Research however takes it a step further. It suggests that it just might not be enough to use voice-activated systems or hands-free kits for road safety — we have to put our brains too on the road. Carried out on 29 volunteers, the study measured changes in brain blood flow patterns using functional MRI (fMRI) as they simulated driving realistically in the laboratory.

There was a 37% reduction in blood flow through the parietal cortex as a result of driving, which is the seat of spatial sensation and navigation in the brain. For drivers a reduction in spatial awareness could prove fatal, as their ability to carry out defensive and avoidance maneuvers at high speeds could be seriously compromised. In fact, a significant deterioration in the quality of driving was noticed in the study — even though the participants were only “listening”. Listening and driving depend on so different parts of the brain, that the neuronal circuits are bound to experience a “clash of interests” so to speak, when it comes to blood flows and activity. The study also found significant deficits in the occipital cortex, which could be linked to visual inattention of the road ahead — another potentially dangerous factor.

Well, not much of an argument over this study I believe, even if you are an excellent, proven multi-tasker.


Lien, M., McCann, R.S., Ruthruff, E., Proctor, R.W. (2005). Dual-Task Performance With Ideomotor-Compatible Tasks: Is the Central Processing Bottleneck Intact, Bypassed, or Shifted in Locus?. Journal of Experimental Psychology: Human Perception and Performance, 31(1), 122-144. DOI: 10.1037/0096-1523.31.1.122

Carnegie Mellon Study Shows Just Listening To Cell Phones Significantly Impairs Drivers. Carnegie Mellon University – Press Release.

Sudip Ghosh, MD

Sudip Ghosh, MD, is a surgeon at the University of Manchester, UK and a medical writer.
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