Washington (Agencies): Connectivity is very important for the human brain's processing speed—and old age destroys it, raising hopes for a cure for cognitive declines, claimed a group of Indian-origin scientists.

A team led by Perminder Sachdev of University of New South Wales has discovered that the brain operates as a highly interconnected small-world network, and not as a collection of discrete regions as previously believed, with important implications for why many have cognitive declines in old age.

In their research, the scientists have mapped human brain's neural networks and connected them to specific cognitive functions such as information processing and language, the 'Journal of Neuroscience' reported.

They are now examining what factors may influence the competence of these networks in the hope that they can be manipulated to reduce age-related decline.

"While particular brain regions are crucial for specific functions, the ability of information flow within and between regions is also crucial. We all know what happens when road or phone networks get clogged or interrupted.

"It's much the same in the brain. With age, the brain network deteriorates and this leads to slowing of the speed of information processing, which has the potential to impact on other cognitive functions," informed Prof Sachdev.

The advent of new MRI technology and increased computational power had allowed the growth of the neural maps, resulting in a paradigm change in the way scientists view the brain, say the scientists.

"In the past when people looked at the brain they focused on the grey matter in specific regions because they thought that was where the activity was. White matter was the poor cousin. But white matter is what connects one brain region to another and without the connections grey matter is useless," added Prof Sachdev.