Brain shrinkage not related to memory capacity

Brain shrinkage, a common symptom of ageing when people enter their 60s, appears to have no impact on an individual's capacity of thinking or learning, according to a research conducted by Australian National University (NAU) scientists, calling for a revision on the long-standing views about the influence of aging on the brain.

It is a common belief that the brain shrinks with age and that this shrinkage is linked to poorer memory and thinking. Another common belief is that greater education, or continued, sustained intellectual activity might allow people to better accommodate the effects of brain ageing.

"Our findings do not support these beliefs," said Professor Helen Christensen, the director of the Centre of Mental Health Research (CMHR) at NAU. "It is known that the brain shrinks over the course of a person's life, although the exact trajectory is not well understood, and there are huge individual differences."

As part of a 20-year study called PATH Through Life initiated in 1999, scientists at CMHR conducted a combination of MRI scans and surveys of 446 people in their 60s in Canberra and Queanbeyan. They found that on average men aged 64 had smaller brains than men aged 60, but despite the shrinkage, cognitive functions such as memory, attention and speed of processing were not affected.

In addition, no evidence was found to support the role of education in protecting against either brain change or cognitive performance.

"These findings are good news for the large proportion of baby boomers out there " and probably better news for the baby boomer women who show no evidence of brain shrinkage over this short period of time," said Professor Christensen.