Researchers map brain areas vital to understanding language

Researchers compared the discourse comprehension abilities of patients with damage to specific brain regions relative to patients without damage to those regions. Each image here represents one slice of the brain and the highlighted areas are those that are important for discourse comprehension. Credit: Aron Barbey

When reading text or listening to someone speak, we construct rich mental models that allow us to draw conclusions about other people, objects, actions, events, mental states and contexts. This ability to understand written or spoken language, called "discourse comprehension," is a hallmark of the human mind and central to everyday social life. In a new study, researchers uncovered the brain mechanisms that underlie discourse comprehension.

The study appears in Brain: A Journal of Neurology.

With his team, study leader Aron Barbey, a professor of neuroscience, of psychology, and of speech and hearing science at the University of Illinois, previously had mapped general intelligence, emotional intelligence and a host of other high-level cognitive functions. Barbey is the director of the Decision Neuroscience Laboratory at the Beckman Institute for Advanced Science and Technology at Illinois.

To investigate the regions that underlie discourse comprehension, the researchers studied a group of 145 American male Vietnam War veterans who sustained penetrating head injuries during combat. Barbey said these shrapnel-induced injuries typically produced focal brain damage, unlike injuries caused by stroke or other neurological disorders that affect multiple regions. These focal injuries allowed the researchers to pinpoint the structures that are critically important to discourse comprehension.

"Neuropsychological patients with focal brain lesions provide a valuable opportunity to study how different brain structures contribute to discourse comprehension," Barbey said.

A technique called voxel-based lesion-symptom mapping allowed the team to pool data from the veterans' CT scans to create a collective, three-dimensional map of the cerebral cortex. They divided this composite brain into units called voxels (the three-dimensional counterparts of two-dimensional pixels). This allowed them to compare the discourse comprehension abilities of patients with damage to a particular voxel or cluster of voxels with those of patients without injuries to those brain regions.

The researchers identified a network of brain areas in the frontal and parietal cortex that are essential to discourse comprehension.

"Rather than engaging brain regions that are classically involved in language processing, our results indicate that discourse comprehension depends on an executive control network that helps integrate incoming language with prior knowledge and experience," Barbey said.

Executive control, also known as executive function, refers to the ability to plan, organize and regulate one's behavior.

"The findings help us understand the neural foundations of discourse comprehension, and suggest that core elements of discourse processing emerge from a network of that support language processing and executive functions. The findings offer new insights into basic questions about the nature of discourse comprehension," Barbey said, "and could offer new targets for clinical interventions to help patients with cognitive-communication disorders.

"Discourse comprehension is a hallmark of human social behavior," Barbey said.

"By studying the mechanisms that underlie these abilities, we're able to advance our understanding of the remarkable cognitive and neural architecture from which emerges."

More information: "Neural mechanisms of discourse comprehension: a human lesion study," www.researchgate.net/publication/256573942_Neural_mechanisms_of_discourse_comprehension_A_human_lesion_study

add to favorites email to friend print save as pdf

Related Stories

Researchers map emotional intelligence in the brain

Jan 22, 2013

A new study of 152 Vietnam veterans with combat-related brain injuries offers the first detailed map of the brain regions that contribute to emotional intelligence – the ability to process emotional information ...

Neuroscientists map intelligence in the brain

Mar 11, 2009

(PhysOrg.com) -- Neuroscientists at the California Institute of Technology (Caltech) have conducted the most comprehensive brain mapping to date of the cognitive abilities measured by the Wechsler Adult Intelligence ...

How do we understand written language?

Dec 16, 2009

How do we know that certain combinations of letters have certain meanings? Reading and spelling are complex processes, involving several different areas of the brain, but researchers from Johns Hopkins University in the ...

Recommended for you

Conceptual representation in the brain: Towards mind-reading

53 minutes ago

Your measured brain signals can reveal whether you are thinking about an animal or a tool. That's what neuroscientist Irina Simanova discovered during her PhD at Radboud University, where she investigated the conceptual representation ...

Researchers track down cause of eye mobility disorder

16 hours ago

Imagine you cannot move your eyes up, and you cannot lift your upper eyelid. You walk through life with your head tilted upward so that your eyes look straight when they are rolled down in the eye socket. ...

How kids' brain structures grow as memory develops

18 hours ago

Our ability to store memories improves during childhood, associated with structural changes in the hippocampus and its connections with prefrontal and parietal cortices. New research from UC Davis is exploring ...

User comments