(NaturalNews) Emotionally charged billboards actually hamper people's ability to drive, according to a study conducted by researchers from the University of Alberta and published in the journal Accident Analysis and Prevention.
Driver distraction is one of the primary causes of motor vehicle accidents, the researchers noted.
"Studies have shown that when subjects see an emotional stimulus as opposed to a neutral one, they're slower in making reaction time responses and they're slower when doing a visual search," lead author Michelle Chan said. "I wanted to see whether the results would carry over in driving - would we also find more distracted performance in driving? - and we did see that."
30 college students took part in a simulation of driving past 20 billboards, each one containing a series of words that were either emotionally positive, negative or neutral. Positive words included cash, excitement, fame, happy, love, sex and win, while negative words included abuse, cancer, prison, stress and war.
In addition to observing the effect of each billboard on the participants' driving, the researchers also instructed participants to push a button on the steering wheel whenever they encountered a particular word. This provided an extra test of participants' awareness and reaction time.
Veering and speeding
The researchers found that when exposed to positive words, participants had a tendency to speed up, although typically not into the range of dangerous speeds. Other driving skills did not seem to be affected.
"With the positive [words], they actually drive pretty well," Chan said.
When encountering negative words; however, participants slowed down, lost focus and tended to drift and veer between lanes. Some of them actually crashed into (simulated) trees, vehicles or even pedestrians.
"There have been studies showing that when you're positively stimulated, your attention broadens, so you perform better when you're in a happy mood," said Chan. "In my results, we also saw that ... participants actually responded faster in the positive block than in the negative block."
Age and gender did not influence the results, but Chan noted that participants with less driving experience were more likely to be distracted.
The study supports the idea that billboards can be dangerously distracting road hazards, Chan said, particularly those designed to appeal to emotions.
"Any kind of distraction is risky when you're driving. But there would appear to be a larger risk when it comes to emotional stimuli."
While some distractions, such as cell phones and radios, are primarily under the drivers' control, billboards are an external factor that they cannot choose to avoid.
"In Australia they have really strict billboard criteria, but in the United States it's less so," Chan said. "When you're driving in Las Vegas, you'll see a bunch of profane billboards. There are also some really graphic anti-smoking billboards around."
The researchers are planning a follow-up study, using a more advanced simulation device, to test participants' response to emotionally charged billboard images, such as those found on anti-smoking ads.
"They tend to capture more attention, so drivers tend to look at them longer and pay less attention to the driving task," Chan said.