Intricate visual tasks may lead to loss of touch

Have you ever failed to notice your phone vibrating or have been pick-pocketed while searching for a friend's face in a crowded place? It is because you were so much engrossed in the visual task that you actually lost the ability to notice that your own wallet was being picked.

According to a new study, people's ability to notice the sense of touch is reduced when they are carrying out a demanding visual task.

The study pointed out an example of cars that now come fixed with tactile alerts and signals the driver when it begins to drift across lanes.

However, the researchers said that the drivers are less likely to notice these alerts when engaging in demanding visual tasks such as searching for directions at a busy junction.

"Our research is particularly important given the growing use of tactile information in warning systems," said Sandra Murphy of Royal Holloway, University of London, in a paper detailed in the Journal of Experimental Psychology: Human Perception and Performance.

For the study, the team asked volunteers to perform a letter search task of either low or high difficulty, as well as respond to the presence or absence of a brief vibration delivered simultaneously to either the left or the right hand.

Their sensitivity to the clearly noticeable tactile stimulus was reduced when they carried out the more taxing visual search task, the authors reported.