There are some movies that have showed that a special class of drugs can switch on unused circuits in the brain. As per long-held belief, average humans are not capable of using more than 10% of their brains. However, researchers have dispelled the 10% brain myth, claiming there are no functionless regions in the average healthy brain. Yes, smart drugs can provide a boost to some brain functions, like memory or attention, but they must not be mistaken to have the potential of activating unused circuitry.

The 10% myth is attributable to early experiments on brains, wherein researchers used electrodes on different parts of the brain and found only 10% of the cortex was twitched by muscles because of the jolts. This was the main reason scientists believed that the other 90% was the silent cortex. Now, scientists have figured out that cognitive functioning depends upon those large areas.

Also, researchers have been trying to explain junk DNA, which is a human genome known to comprise long strings of genetic code, but do contribute in building proteins. An international gene-mapping effort known as Project ENCODE found two years ago that non-coding DNA played a vital role in controlling the expression of genes. After discovering this, scientists claimed that specific biochemical activity was produced by 80% of the genome.

A study published in Genome Biology has revealed that development of brain tumors is associated with an activity in non-coding DNA and RNA.

"We cannot simply ignore the remaining 90% of the genome that is not evolutionarily conserved. Evolution can tell you whether something is important or not important, but it doesn't tell you what that something actually does", said Manolis Kellis, a computational biologist at MIT.