Hard to swallow: April 2005

Research by the French Laboratory of Neurobiology and Cognition has shown that the old adage 'time flies when you're having fun' could be more than mere conjecture.

In a study where 12 volunteers watched an image - concentrating either on its duration, colour or both - while researchers monitored their brain activity using MRI scans, results showed that a network of brain regions called the corticostriatal loop increased their activity when the subject paid attention to the duration of the image.

Translated into real terms, this means that if the brain has to focus on many aspects of a task it will be forced to spread its resources thinly, and will therefore pay less attention to the passing of time, meaning that it will seem to pass faster. Conversely, if the brain is not highly stimulated it will concentrate its full energies on monitoring the passing of time, meaning that it will seem to take longer to pass. Unfortunately for some, this latter state of affairs also proves to give the most accurate perception of time.

Lead researcher Dr Jennifer Coull said: 'many areas of the brain involved in estimating time also play a key role in controlling movement and preparing for action. It is because of this overlap that we think that the brain may make sense of time as intervals between movements in much the same way as a musician marks time with his foot, or an athlete anticipates the sound of a starter's pistol.'