Modern Life May Be Shrinking the Hippocampus. Here's How to Grow It
Locked away within the recesses of your brain is the seahorse-sized hippocampus. Its two interlocking parts are small relative to the rest of the brain, but they perform outsized roles in cognitive function. Decades of research have revealed the hippocampus to regulate impulses and self-control, memory of times, places, and associated emotions, as well as spatial memory and navigation. Put more simply, the hippocampus is a pivotal determinant in how we interact with and remember the world around us. Moreover, it's extremely plastic, meaning that it changes throughout life depending on factors like environmental stimuli, damage, learning, and use.
That's why Véronique Bohbot, a researcher at the Douglas Mental Health University Institute and an associate professor in the department of Psychiatry at McGill University, is mildly concerned with what she sees as a growing trend of hippocampal disuse. As Bohbot told journalist M.R. O'Connor for O'Connor's new book Wayfinding: The Science and Mystery of How Humans Navigate the World , "the sedentary, habitual, and technology-dependent conditions of modern living today are changing how children and adults use their brains."
"People who have shrunk hippocampus are more at risk for PTSD, Alzheimer's, schizophrenia, and depression. For a long time we thought the disease causes shrinkage in the hippocampus. But studies show that the shrunk hippocampus can be there before the disease."
At this time, Bohbot's hypothesis is more intriguing than cause for actual alarm, but it does raise a key, two-part question: What about modern life can cause the hippocampus to shrink, and how can people prevent or even reverse the decline?
While the brain isn't actually a muscle, like muscle, it does require exercise to stay in shape – mental exercise. In particular, the hippocampus seems to be flexed by spatial navigation, something Bohbot says we're doing less and less of.
"Maybe in the past we never had to go on autopilot," she told O'Connor. "Having jobs in one location and lives being more habitual is new. Industrialization learned to capitalize on the habit-memory-learning system."
"Compounding these societal changes is the fact that chronic stress, untreated depression, insomnia, and alcohol abuse can all shrink hippocampal volume," O'Connor added. Indeed, compared to other brain regions, the hippocampus seems uniquely prone to atrophy.
But fret not, research has identified a number of potential ways to maintain your hippocampus and even grow it. Video games that challenge spatial navigation, like Super Mario 64 or Portal, may be beneficial. Habitual physicial exercise helps. Regular meditation seems to work. Even simple things like exploring your environment, taking weekend trips to unseen places, and incorporating new activities into your daily life could be a boon. And of course, getting plenty of sleep works wonders, as well.
There are signs that the hippocampus is shrinking on average as human life grows increasingly automated, but it's still more than possible to stave off this decline with a few, focused actions.