MIT and Boston University researchers found that activity in the human brain's language processing network remains nearly identical in younger and older adults, according to a study published in Nature Communications.
Brain scans showed that while language areas remained stable, the multiple demand network—a system responsible for executive control, problem-solving, and working memory—showed measurable decline with age. Older participants exhibited reduced synchronization, smaller activated brain regions, and weaker overall activation magnitude during spatial memory tests.
The team evaluated two cohorts spanning ages 17 to 39 and 41 to 80. Participants completed reading and listening tasks to locate language networks, alongside spatial grid-memory exercises to pinpoint executive demand regions.
Older subjects exhibited the same neural sensitivity as younger subjects when encountering unfamiliar words or complex grammatical structures. Senior co-author Evelina Fedorenko, an associate professor at MIT's McGovern Institute for Brain Research, noted that activity rose in response to linguistic difficulty across both age brackets.
Anne Billot, who co-led the study during her doctorate at BU before moving to Harvard University, reported that language networks showed no sign of blurring into the multiple demand network with age. Former MIT research assistant Niharika Jhingan served as co-lead author, and Swathi Kiran of BU was senior co-author.
Vocabulary accumulation over decades may support this preservation. Fedorenko observed that sustained exposure to text and speech allows language processing to stay robust, comparing the effect to a language model trained on continuously expanding data.
The National Institute on Deafness and Other Communication Disorders funded the research. Additional support came from the Simons Center for the Social Brain, the Poitras Center for Psychiatric Disorders Research, the Quest for Intelligence, and the McGovern Institute.
