Senior moments explained

When you experience a mental lapse and charge it to being a “senior moment,” congratulate yourself because aside from being an excuse, you may be neurologically right.

If you are chronologically “old” and you begin to feel like you find it more difficult to remember, recognize or connect things, and you have had yourself checked and you really do not show any signs you have a neurological disease, then you should probably concede — you just have a senior brain. Neuroscientists figured out a way to see if senior moments were indeed real. Their findings were published in the journal Neuron in December 2007 entitled Disruption of Large-Scale Brain Systems in Advanced Aging led by Jessica R. Andrews-Hanna. In that study, they hooked the brains of 93 healthy adults aged 18 to 93 to brain scans and made them undergo mental tests. They found that indeed, the older subjects performed rather poorly compared to the younger subjects in areas that required the coordination of major brain regions that support “cognition” — which embraces mental powers of awareness, reasoning, judgment and perception. They found that there have been “disruptions” (not the amyloid protein that is the culprit in Alzheimer’s) in the white matter of older people and white matter is what largely serves as the labyrinth that connects the brain regions.

More recently, neuroscientists who published a study in the early edition of the Proceedings of the National Academy of Sciences also confirmed what really happens to the brain between people who are 25-28 years old and those who are 66-71 years old. They wanted to specifically test these groups because it has always been known that a substance naturally produced in the brain called dopamine, lessens as one ages. Dopamine is a hormone and a neurotransmitter which is associated with feelings of excitement when you anticipate a reward and/or when you actually get a reward. 

The study found that when anticipating a reward, the young subjects “recruited the ventral striatum, the anterior cingulate cortex, and the left intraparietal region” while “older subjects recruited only the left intraparietal region and this was the sole brain area commonly activated by young and older subjects during reward.” This means that when just thinking of a possible reward, the “dopamine heavy weights” (young ones) activate a lot more regions in their brain while the older ones only show that they activate only one area. The neuroscientists did not offer possible explanations to this (none that I could yet understand anyway through the jargon). However, I would like to think that since older people have more experience in gauging the likelihood of a reward really materializing, the “excitement” may understandably be muted, and may really mean less “brain parties” excited by dopamine.

When it comes to having the reward, both groups — young and old — had the same parts of the brain — bilateral fronto-parietal network — activated. The activation was just a little “muted” in the older subjects. We have to remember that the older people here are healthy or what the study called “successful agers” — those who do not show signs of any abnormal mental functions associated with low dopamine. People with illnesses that are characterized by low dopamine (like Parkinson’s Disease) severely lack motivation. The older people in the study who have naturally low dopamine are probably the ones you characterize as those who have “gracefully surrendered the things of youth” and are just too happy to do so.

It would be really interesting to see this difference examined in the heads of the fans of the ADMU vs DLSU match this weekend. I want to see how the feeling of reward for every score, by either side, that registers in the “left intraparietal region” of an aging Atenean or La Sallite compares to that of their younger counterparts. I want to see if dopamine could even squeeze its role in the expected crowd in Araneta.

So yes, growing old may mean “disruptions in white matter integrity and poor cognitive performance across a range of domains” as the study on the aging brain cited but remember, it is also how other studies somewhat describe the attention span of young people now growing up in this age of stupendous information available to them than ever before in the history of humankind. Some young kids may already be having their senior moments too soon.

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