By Clara Colombatto

The fact that “different people speak language differently” is one of the major challenges in uncovering the neural basis of language. Brain structure and function differ highly among individuals, and this is the core of the new discipline of cognitive neurolinguistics. Duke professor Edna Andrews explained the fascinating complexity of language research at the Regulator Bookshop on Tuesday, March 4.

Edna Andrews gives an overview of the new field of cognitive neurolinguistics at the Regulator Bookshop for Brain Awareness Week Credit: Clara Colombatto

Edna Andrews gives an overview of the new field of cognitive neurolinguistics at the Regulator Bookshop for Brain Awareness Week (Photo: Clara Colombatto)

A linguist by training, Edna Andrews is the Nancy & Jeffrey Marcus Distinguished Professor of Slavic & Eurasian Studies, Chair of the Linguistics Program and holds appointments in Cultural Anthropology and the Duke Institute for Brain Sciences. Over time, Andrews’s research interests led her to neuroscience — so she went back to the classroom, studied as a beginning student with neurobiologist Gillian Einstein and shadowed a team of neurosurgeons at Duke Hospital.

This range of disciplines is fundamental for Andrews’ pioneering work in the field of cognitive neurolinguistics. Observations of brain-damaged patients led to a 19th century model that held that language centers are mainly in the left hemisphere of the brain. In particular, language was thought to be dependent on grey matter, the part of the brain that contains mostly cell bodies and is responsible for information processing, as opposed to white matter, which contains mainly long-range connection tracts (axons) and is responsible for information communication. Researchers realized this understanding was an oversimplification when surgeons started to notice that cutting white matter tracts alone significantly impaired linguistic abilities. New methods, such as electrical stimulation of the brain during surgeries in awake patients, led to the realization that the whole brain is involved in language.

White matter fiber tracts of a human brain visualized with a Tensor Imaging technique. The U-shaped fibers connect the two hemispheres. The finding that these tracts are essential for language revolutionized the field of neurolinguistics because language was previously thought to be localized to gray matter in the left hemisphere. Credit: Thomas Schultz via Wikimedia Commons

White matter fiber tracts visualized with a tensor imaging technique. Findings that the fibers  connecting the two hemispheres are essential for language revolutionized the field of neurolinguistics.
(Photo: Thomas Schultz via Wikimedia Commons)

When theoretical linguists such as Andrews joined the conversation, they merged empirical data with theory to answer questions such as, is language learned or innate? Are there specific structures and localized circuits in the brain responsible for language? And are there critical periods where our brain is particularly sensitive to changes?

The picture is complicated by the fact that “most of the world population is bi or multilingual,” and “one could argue that in fact there are no monolinguals.” In our daily lives, we use different languages at school, at work and at home (Learn more about this hypothesis here). Andrews’ current work addresses these complexities by looking at changes in neural activity as individual speakers acquire Russian as a second or third language. Her latest book “Neuroscience and Multilingualism,” coming out at the end of the year from Cambridge University Press, is an exploration of the neuroscientific modeling of multilingualism.

The lecture was part of Brain Awareness Week, a global campaign to encourage public interest in the progress and benefits of brain research. Not to miss: Michele Diaz on “Language and the Aging Brain” on Thursday, 3/5 at 7:30pm, and Richard Mooney on “Music and the Brain” on Friday, 3/6 at 6 pm at Motorco Music Hall.