A bigger brain is not necessarily a better brain.
At least not a better-functioning brain in terms of memory (and certain other cognitive functions).
At least, that’s the the conclusion of a recent study from Michigan State University in which researchers used MRIs to analyze two aspects of the brain, the size of the hippocampus and the amount of white matter linking the hippocampus to the rest of the brain.
The hippocampus is that now-famous part of the brain intimately linked to memory (and other cognitive functioning), and it’s well-established that hippocampus shrinks with age (as, of course, does nearly every body part you’d like to keep staying its young-adult size), and a smaller hippocampus has been linked in many studies to poorer memories..
But according to this research, “a larger hippocampus does not always reliably predict learning and memory abilities in older adults” because a lot of how well your memory works also depends on the rest of your brain’s status, especially on how well your hippocampus is connected to the rest of the brain through white matter connections.
Bottom line: A bigger brain is not necessarily a better brain, which will come as good news of course, to the many of us who start out with smaller brains in the first place.