“Take it easy driving - the life you save may be mine.”
- James Dean
A study published in Neuroscience Letters proposed that dangerous drivers are worse at processing angry faces than are their safer driving counterparts.
This study was conducted by Yan Ge, Xinze Liu, Jing Chai, and Weina Qu at the Institute of Psychology and the University of Chinese Academy of Science in Beijing, China.
Previous research has documented that certain drivers have particularly aggressive, risky, and angry driving behaviors. These dangerous drivers more frequently acquire traffic violations and get into traffic accidents.
When an individual develops a negativity bias, they tend to register and process negative events more readily than positive and neutral events. While driving, research suggests a negative event can influence steering angles and increase deviations from the centre of the road. Negative events causing anger have been shown to produce decreased perceptions of driving risks.
The purpose of this study was to examine the differences in emotional face processing between safe and dangerous drivers. The researchers hypothesized that more dangerous drivers would show a negativity bias by processing angry faces differently than would safe drivers, and that this difference in angry-face processing would relate to the number of driving infractions they had accrued.
Study and findings
Participants were recruited based on their driving history (i.e., total kilometers driven, years of driving and amount of days driven in a week). Once the initial data was gathered, participants were divided into two groups depending on driving penalty points accumulated throughout the previous year. Individuals with six or more acquired penalty points were assigned to the dangerous driver group, whereas individuals with less than six penalty points were assigned to the safe driver group.
Additional information was collected from participants regarding their propensity for dangerous driving using scores obtained from The Dula Dangerous Driving Index (DDDI). Self-report questionnaires were administered to find out about an individual's driving experience and traffic violations.
In order to measure how individuals process emotional information, an emotional Stroop task was completed by all participants. Participants were required to name the colour (e.g., blue or red) of an angry face or a neutral face. Four different faces were used for each angry or neutral stimulus, with two female faces and two male faces. A total of forty-eight trials, with six subsequent face presentations in each trial was completed. Each trial started when a participant was presented with a colored face (e.g., blue or red) and ended with the participant naming the color.
Electroencephalogram (EEG) techniques were used to measure brain activity from certain brain regions, triggered by the event of being presented with facial stimuli, via electrodes placed on the scalp. Event-related potentials were analyzed based on the amplitude of the peaks and valleys produced by the type of facial stimuli presented.
Two specific brain waves were of particular interest to the researchers. The P200 wave which is represented by a positive amplitude (baseline to peak), at approximately 100 to 250 milliseconds after a stimulus is seen. The P200 amplitude has been related to the allocation of attention in facial emotional processing.
The N170 wave is represented by a negative deflection, at 100 to 200 milliseconds after a stimulus presentation, and reflects how one constructs facial representations during early processing of visual cues on the face. Previous research has found that angry faces tend to produce larger amplitudes (of N170 waves) than fearful or happy faces.
The results revealed that dangerous drivers produce smaller P200 amplitudes when presented with angry and neutral faces compared to safe drivers and smaller N170 amplitudes when processing angry faces, suggesting that dangerous drivers take longer to process emotional stimuli. These findings support the researchers’ hypothesis because reduced amplitudes observed in dangerous drivers’ EEG results can be linked to insufficient categorization of emotional stimuli.
Dangerous drivers can be recognized by their aggressive and risky driving behaviors. These drivers seem to have a hampered ability to process emotional faces suggestive of a negativity bias that leads them to fail to take in relevant information in emotionally-charged driving situations.