Spark

by John J. Ratey

There was a nun named Sister Bernadette who died of a heart attack at age eighty-five in the mid-1990s. Along with more than six hundred other nuns, she donated her brain to science as part of an ongoing study conducted by epidemiologist David Snowdon, who memorialized the School Sisters of Notre Dame, in Mankato, Minnesota, in his inspiring book, Aging with Grace. The nuns constantly challenge their minds, with vocabulary quizzes, mental puzzles, and debates about public issues, and many of them live to be one hundred or more. The interesting thing about Sister Bernadette is that she scored in the ninetieth percentile on cognitive tests right up until she died, but when her brain was examined postmortem, it showed massive damage from Alzheimer’s disease. Tissue from her hippocampus to her cortex was riddled with plaque and neurofibrillary tangles to the most extensive degree, and she also carried the ApoE4 gene variant. In other words, she should have been utterly lost to the ravages of dementia. Yet despite the damage in her brain, she remained mentally sharp. Snowdon points to the notion of cognitive reserve as a possible explanation. This is the brain’s ability to adapt and compensate for damage by recruiting other areas to help with tasks. By teaching until a late age and staying mentally active, Sister Bernadette almost certainly trained her brain to work around the genetic hand she was dealt. Her example, like that of my mother, is one to live by.