Brain's codes for noun meanings

Identifying thoughts through brain codes leads to deciphering the brain's dictionary

Two hundred years ago, archaeologists used the Rosetta Stone to understand the ancient Egyptian hieroglyphs. Now, a team of Carnegie Mellon University scientists has discovered the beginnings of a neural Rosetta Stone. By combining brain imaging and machine learning techniques, neuroscientists Marcel Just and Vladimir Cherkassky and computer scientists Tom Mitchell and Sandesh Aryal determined how the brain arranges noun representations.

Understanding how the brain codes nouns is important for treating psychiatric and neurological illnesses.

"In effect, we discovered how the brain's dictionary is organised," said Just, the D O Hebb professor of psychology and director of the Center for Cognitive Brain Imaging. "It isn't alphabetical or ordered by the sizes of objects or their colours. It's through the three basic features that the brain uses to define common nouns like apartment, hammer and carrot."

As the researchers report today in the journal PLoS One, the three codes or factors concern basic human fundamentals: (1) how you physically interact with the object (how you hold it, kick it, twist it, etc.); (2) how it is related to eating (biting, sipping, tasting, swallowing); and (3) how it is related to shelter or enclosure. The three factors, each coded in three to five different locations in the brain, were found by a computer algorithm that searched for commonalities among brain areas in how participants responded to 60 different nouns describing physical objects.

For example, the word apartment evoked high activation in the five areas that code shelter-related words.