Researchers have captured the way the meaning of language is organized across the brain by monitoring the neural activity of human subjects while listening stories.
According to The Globe And Mail, the result of this study could help understanding how people can bounce back from brain-related injuries that affect language, such as strokes. The research also shows more broadly how mental processes in virtually every region of the brain are engaged by our capacity to understand speech.
Alex Huth, lead author of the study and a postdoctoral researcher at the University of California, Berkeley, said that this for the first time a team of scientists was able to create this type of "semantic map" of the human cerebral cortex. The mind map is showing where different concepts are represented. The new study was published in the scientific journal Nature.
Previous studies have already shown that particular ideas or words light up certain brain areas. But the new map goes much further by showing that many words are associated with multiple regions and presenting in detail the activity within these regions.
Data from seven individuals who each spent about 6 hours listening to real-life stories from a public radio program called "The Moth Radio Hour" was used by the research team to create the map. The researchers monitored the brain responses to the stories using functional magnetic resonance imaging (fMRI).
This is a technique that subdivides the brain into "voxels," many thousands of tiny compartments. The blood oxygen levels in each one of these "voxels" are monitored and used as a measure on how hard the brain cells located within each of the compartments are working.
A map of the brain was created in order to help researchers decode people's inner thoughts. The "semantic atlas" shows in multiple dimensions and vivid colors how the human brain organizes language.
According to Science Daily, study senior author Jack Gallant, a UC Berkeley neuroscientist, explained that these brain maps are broadly consistent across individuals, but "there are also substantial individual differences." In order to map these individual differences in detail, scientists will need to conduct further studies across a larger and more diverse sample of people.