AUSTIN—Strokes are common in old age, but these devastating events also strike babies. That’s likely because birth is stressful and particularly hard on the body’s blood vessels and circulation. But unlike adults, babies who suffer a stroke in the area of the brain that deals with language retain the ability to communicate. In new work presented here yesterday at the annual meeting of AAAS, which publishes Science, researchers found that as teenagers, individuals who experienced strokes around the time of birth are able to understand language as well as their healthy siblings. To find out how adults who had strokes as infants compensated for such severe brain damage, the team imaged their brains while they listened to sentences read forward and backward. In healthy adults, the test causes language processing areas on the left side of the brain to light up with activity (pictured above on the left). In the stroke survivors, who had lost brain tissue in this region, the activity had shifted to an area in the right hemisphere that’s the mirror image of the normal language region (above, right). This right hemisphere region is almost never used for understanding language in healthy people, and adults who have had a stroke do not enlist it for speech processing. The researchers suspect that the infants benefit from a unique window during development when the brain is flexible enough to make these accommodations. Figuring out what allows for that elasticity may one day help adult stroke survivors regain the ability to speak and understand language, the researchers say.
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