London: Face and voice are the two features by which people recognise other people. Now, researchers have discovered what they claim is a direct link between the areas of human brain responsible for voice and face recognition.

A team at Max Planck Institute in Germany says that the exchange of information -- assumed to take place between these areas via this direct connection consisting of fibre pathways -- may help in quickly identifying familiar people in everyday situations and also under adverse conditions.

Theories differ as to what happens in the brain when we recognise familiar persons. Conventionally, it is assumed that voice and face recognition are separate processes which are only combined on a higher processing level.

However, recent findings indicate that voice and face recognition are much more closely related. The team earlier found that areas of brain responsible for the identification of faces also become active when people hear a familiar voice.

"We now assume that areas in the brain which are involved in voice and face recognition interact directly and influence each other," said team member Helen Blank.

In the latest research, the researchers could show that a structural connection between voice and face recognition areas exists. They used diffusion-weighted magnetic resonance imaging, a method with which the course of white matter tracts in brain can be reconstructed when combined with tractography, a mathematical modelling technique.

The team had located the areas responsible for voice and face recognition in her study participants by measuring the reactions of the brain to different voices and faces using magnetic resonance imaging.

They discovered a direct connection consisting of fibre pathways between the voice and face recognition area.

"It is particularly interesting that the face recognition area appears to be more strongly connected with the areas involved in voice identification, despite the fact that these areas are further away than areas which process information from voices on a more general level.

"The finding is of interest for research on unusual neurological conditions, such as prosopagnosia and phonagnosia, which prevent people from being able to recognise others from their faces or voices," Blank said.