Hidden images can affect your driving speed

The speed you drive at is often presented as purely a conscious and purposeful choice. However recent research from the University of Groningen published in the journal PLoS ONE suggests that speed choice is not purely conscious, for instance, emotions you may not even know you are having, may impact on the speed at which you drive.

Driving is a well learnt and highly automatic task, and as such many of your decisions are affected by influences outside of what would be considered consciousness. One such influence could be physiological emotions which can occur without becoming consciously experienced feelings. The upshot being that while you may not know it, your emotional reactions to the world around you may impact on the way you drive without your full conscious control.

Traffic research scientists at the University of Groningen had 85 participants drive in a simulator while emotionally negative or neutral images were shown very quickly in the upper centre of the screen. These emotional images were ‘masked’ by other images which were shown for longer time periods. This effectively hides the faster images from conscious perception.

The result is that the female participants drove almost 3 km/h slower on average when the negative images were being presented. This occurred despite the participants being unable to report seeing any of the emotionally negative images and without any clear changes in their conscious feelings. Researcher Ben Lewis-Evans says “Furthermore, if the heart rate of the participants is examined, what you can see is that they generally relax over the period of the drive. However the negative images seem to have suppressed this normal relaxation process contributing to slower driving speeds on average”. Ben adds “That we found any effect at all is interesting, given that previous research in this area has mainly been carried out in highly controlled and relatively simple experimental conditions and not with complex real world tasks like driving”.

The male participants did not show any clear reaction to the masked images. This could be related to gender differences in reactions to emotionally charged images or simply due to issues with sample size (26 male, 59 female).

Ben admits that while you are not going to start showing masked images to people to slow them down, this research is important as it shows that the processes behind speed choice are more than what you can see on the surface. This has implications for how we design the environments in which people drive, and the campaigns that we use to ensure they are driving safely.

The research is published today in the open access journal PLoS ONE. Reference: Lewis-Evans, de Waard, Jolij, & Brookhuis (2011) What you may not see might slow you down anyway: Masked images and driving. PloS ONE, http://dx.plos.org/10.1371/journal.pone.0029857

Note to editors

For further information please contact Mr Ben Lewis-Evans, b.lewis.evans rug.nl , +(0)50-363 3190/7601 (secr)