Highlights of the middle-aged brain

A while back I read a review paper, ‘Age-associated cognitive decline’, by Deary et al. (2009). The paper is really useful but the title speaks volumes and certainly influenced my thinking about the topic of ageing and cognition. So, it was with a great deal of pleasure that I read Barbara Strauch’s book, ‘The Secret Life of the Grown-Up Brain’, (Strauch, 2011a). (Actually, I heard her speak about the book to the RSA (Strauch, 2011b) so I knew the general thrust of the argument.) The book is written with a popular reader in mind but is grounded in a lot of references – the backlog of papers that I really ought to read is certainly longer than it was before I started this book.

So, the basic point is – middle age is not all bad and actually there are some developments in middle age that are actually quite positive and worth celebrating. (I should note that she defines middle age as running from 40 – 65, which puts me just inside this bracket and therefore with a vested interest.) But, for this project of understanding object handling, understanding how the brain changes across this period is potentially really helpful when trying to understand reminiscence sessions.

So, the highlights…

(1) Older people clearly show a preference in memory and attention for the positive over the negative (p.34ff). The researchers interviewed had no pinned down why this was so and posited that older brains deliberately select positive information out of the environment because it suits their purposes. They suggest that, because we’re that bit nearer to death, we need to make the most of the time available to us, so it is more important to maintain emotional stability and this is reinforced through focusing on the positive.

(2) (My favourite.) There are, apparently, cognitive mechanisms seemingly in the frontal lobes that help us stay focused on task and inhibit any distracting or irrelevant input – these become less effective with age, i.e. we become more distracted (p.79ff). (Although, oddly, it also becomes harder for us to switch tasks.) Anyway, and this is the bit I like, Strauch suggests that the same increase in distraction can also lead to a broader, less focused attention span (p.88) which may be of value when in an information-rich environment and may also prove to be an element within creativity.

(3) Education and cognitively stimulating activities can help develop cognitive reserve which, in turn, can help to create a buffer against the effect of the plaques and tangles formed as part of Alzheimer’s Disease (p.116ff). She quotes a researcher, Nick Scarmeas, as saying “Overall, the accumulated data seems to make a case for a protective effect of physical, intellectual and social activities for cognitive decline and dementia”. Whilst Strauch acknowledges that this is a contentious area, she is clearly supportive of the idea and raises the subsequent question – at what point do you have to start engaging in these activities for them to have an effect?

(4) Researchers have observed new neurons being formed in adult mice in a region of the hippocampus called the dentate gyrus. The researchers suggest that the formation of these neurons is linked to the formation of associations between different aspects of the memory (p.136). What underpins this is a model of memory wherein the different aspects of a single memory are stored across the brain and then integrated within the hippocampus. An interesting observation: “Our memories are notoriously unreliable, in part because we are constantly pulling up old memories and ‘re-tagging’ them with new information, then restoring the memory in a modified form”.

(5) Aerobic exercise is good for your brains.

(6) Put simply, neurons have an input-end and an output-end; the link between the main neuron body and the output-end is called the axon; in many neurons, axons have a fatty sheath called myelin; myelin acts as an insulator resulting in increased signal transmission speed along the axon and improved integrity of the signal. When people talk about brains they sometimes talk about the ‘grey matter’, which is comprised of the neuron cell-bodies, and the ‘white matter’, which is comprised of the myelinated axons. The volume of white matter increases as we age, into our fifties or sixties. Myelin may get damaged but it can also be repaired. At some point, the repair processes break-down (p.158ff). Some researchers suggest that middle age represents a cusp between effective repair and the beginnings of decline.

(7) Socialising is a form of exercise for the brain. Engaging in social interaction is cognitively demanding on many areas of the brain – from recognising faces to participating in meaningful conversation (p. 188). Tasks or workshops that involve a significant social element may well prove valuable in the extent to which they gently tax the brain and encourage it to work.

(8) Throughout the book there is a repeated observation that diversity in the condition of people brains (when looking across a population) becomes much greater in middle age than in any life-period before or after.

Although I noted at the outset, that the book was relevant to thinking about reminiscence. I’m beginning to wonder whether it says more about the role of social and physical engagement earlier in life as a preventative measure. There is almost certainly a role for cultural heritage within that.

References

Deary, I.J. (2009) ‘Age-associated cognitive decline’, British Medical Bulletin, 92, 135–152

Strauch, B. (2011a) The Secret Life of the Grown-Up Brain: Discover the Surprising Talents of the Middle-Aged Mind, London: Penguin Books

Strauch, B. (2011b) The Secret Life of the Grown-Up Brain, Lecture given at the RSA on 6th April, 2011. Available at http://www.thersa.org/events/audio-and-past-events/2011/the-secret-life-of-the-grown-up-brain [Last accessed 14/07/11]

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About Bruce Davenport

Museum educator and researcher.
This entry was posted in ageing, Cognition. Bookmark the permalink.

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