Science solves kissing puzzle– why you shut your eyes

with our brain’s inability to process all the sensations suddenly pouring from our lips and tongues as well as visual data.

‘‘Tactile awareness depends on the level of perceptual load in a concurrent visual task,’’ said Polly Dalton and Sandra Murphy, cognitive psychologists at Royal Holloway, University of London, in the Journal of Experimental Psychology: Human Perception and Performance.

Dalton and Murphy’s research did not actually involve people kissing.

Instead they asked people to carry out visual tasks while measuring if they could simultaneously detect something touching their hands.

Their findings showed that, as the visual task became more complex, the subject’s ability to detect tactile sensations declined.

The key finding was that visual sensations overruled tactile ones, also explaining why vibrating devices used to warn drivers and pilots of imminent danger often go unnoticed.

Dalton said: ‘‘If we are focusing strongly on a visual task, this will reduce our awareness of stimuli in other senses.

‘‘It is important for designers to be aware of these effects, because auditory and tactile alerts are often used in situations of high visual demand, such as driving a car or flying an aircraft.’’

However, sometimes, said Dalton, people want to focus on tactile sensations, for example when dancing, reading braille, kissing or making love – all situations in which people often shut their eyes.

Dalton said: ‘‘These results could explain why we close our eyes when we want to focus attention on another sense. Shutting out the visual input leaves more mental resources to focus on other aspects of our experience.’’