Listening to the radio and driving might be more dangerous than once thought.
Driving is an activity that quickly becomes second nature, with more than 75 percent of adult American workers driving to their jobs daily.
Because driving an automobile is common across society, it is easy to forget the inherent dangers associated with controlling a lump of metal as it careers along asphalt at 50 km/h.
The current research reminds us that what we do while we are behind the wheel can still be dangerous, regardless of how confident a driver we are.
Researchers, led by Gillian Murphy from University College Cork, Ireland, and Ciara Greene, PhD, from University College Dublin, Ireland, show us how important it is to keep our attention firmly on the road.
The team designed a study to investigate the so-called perceptual load theory of attention. This theory states that we only have a finite quantity of attention at our disposal. Once we reach that maximum, we can not process any other information.
Could audio interfere with visual information?
The perceptual load theory was first penned by Prof. Nilli Lavie in the mid-1990s and has since received a great deal of research and discussion. The latest study set out to investigate whether information being delivered to one sense (hearing) could affect the awareness levels in a different sensory modality (sight).
Using a full-size driving simulator, the researchers measured whether listening to a traffic report on the radio would impact their ability to take in and process visual information.
In total, 36 drivers took part in the experiment. Half of the participants were asked to listen out for when the traffic reporter changed from a male to a female voice - a low attentional load. The other half were told to listen out for updates on a specific road, the N248 - a high attentional load task.
Would you miss an elephant on the side of the road?
While the participants drove their vehicle, the researchers measured a number of aspects of their driving performance and also threw in the occasional, visual surprise. Every so often, the simulator would insert an elephant or gorilla by the side of the road.
Common sense says that, whether you are listening out for information about the N248 or not, you would notice a giant mammal on the sidewalk. The results of the study show otherwise.
Of the participants in the low-load group, 71 percent registered the presence of an animal; in the high-load group, only 23 percent noticed the elephant in the room.
Additionally, the investigators noted that the high-load group performed less well when it came to obeying yield signals, recalling what vehicles had just passed and other driving performance measures such as lane position, speed and reaction time to hazards.
"Anything that draws our attention away from driving can be problematic, even if it's auditory like listening to the radio or having a hands-free phone conversation. That doesn't mean that we should ban radios in cars, but that we should all be aware of the limits of our attention."
The results were clear and perhaps surprising, considering that listening to a traffic update is a real-world common occurrence. The researchers conclude that perceptual loads can have cross-modal effects. In other words, paying attention with one sense can prevent other senses from paying as much attention as they normally might.
Comprising just 36 drivers, the study is only small-scale, so future research will be necessary to firm up the findings. However, if the results are confirmed, it will demonstrate that attentional load could be a significant contributor to driver inattention and distraction.
"Road safety campaigns are so focused on telling us to keep our eyes on the road, and this is certainly important, but this research tells us that it's simply not enough. We should focus on keeping our brains on the road."