London, Jul 12 (IANS): Due to a combination of genetic factors and individual life experiences, no two people, including twins, share the same brain anatomy, finds a study that suggests the use of MRI scans over fingerprints for personal identification.

Like fingerprints are unique in every individual, so is the central switchboard inside our heads, said Lutz Jancke, Professor at the University of Zurich.

"The combination of genetic and non-genetic influences clearly affects not only the functioning of the brain, but also its anatomy," Jancke said.

Professional musicians, golfers or chess players, for example, have particular characteristics in the regions of the brain which they use the most for their skilled activity.

However, events of shorter duration can also leave behind traces in the brain: if, for example, the right arm is kept still for two weeks, the thickness of the brain's cortex in the areas responsible for controlling the immobilised arm is reduced.

"We suspected that those experiences having an effect on the brain interact with the genetic make-up so that over the course of years every person develops a completely individual brain anatomy," Jancke explained.

To investigate the hypothesis, the team examined the brains of nearly 200 healthy older people using magnetic resonance imaging three times over a period of two years.

Over 450 brain anatomical features were assessed, including very general ones such as total volume of the brain, thickness of the cortex, and volumes of grey and white matter.

The researchers were able to identify an individual combination of specific brain anatomical characteristics for each, whereby the identification accuracy, even for the very general brain anatomical characteristics, was over 90 per cent.

"With our study we were able to confirm that the structure of people's brains is very individual.

"Just 30 years ago we thought that the human brain had few or no individual characteristics. Personal identification through brain anatomical characteristics was unimaginable. Personal identification through brain anatomical characteristics was unimaginable," Jancke said.

However, the replacement of fingerprint sensors with MRI scans in the future is unlikely, as MRIs are too expensive and time-consuming in comparison to the proven and simple method of taking fingerprints, he noted.