The sentence is regularly used in our conversations these days. Last year I celebrated my 70th birthday, and Jaya will celebrate it this year. It is widespread to hear such statements among our friends and at home. It is supposed to happen this way as we grow old. Everybody says so. It must be right. The statement is as accurate as a statement when one of my nephews told me years back. He said, “It must be true; I read it in the newspaper.” My nephew was young and naïve. We are supposed to forget things as we grow old is a statement that makes us old and naïve!
Then what is right? Yes, you may forget a few things, but that is not much related to ageing. People forget things when they are young, they are middle–aged, or they are old. It can happen more if there is damage to brain–related functions. But otherwise, it is common and human to forget.
What is human memory?
Memory refers to the processes used to acquire, store, retain, and later retrieve information. There are three major processes involved in memory: encoding, storage, and retrieval. Human memory consists of the ability to both preserve and to recover information we have learned or experienced.
The memories are two types, short term and long term.
Short-term memory contains the contents of your thoughts right now, including what you intend to do in the next few seconds. It’s doing some mental arithmetic, thinking about what you’ll say next in a conversation or walking to the hall closet to get a pair of socks.
Short-term memory is easily disturbed or disrupted. It depends on your actively paying attention to the items that are in the “next thing to do” file in your mind. You do this by thinking about them, perhaps repeating them repeatedly (“I’m going to the closet to get socks”). But any distraction — a new thought, someone asking you a question, the telephone ringing — can disrupt short-term memory. Our ability to automatically restore the contents of the short-term memory declines slightly with every decade after 30.
But age is not the primary factor so commonly assumed. Some teachers who have been teaching undergraduate class, attest that even 20-year-olds make short-term memory errors. They walk into the wrong classroom; they show up to exams without the requisite No. 2 pencil; they forget something told to them just said two minutes before. These are like the kinds of things 70-year-olds do.
The relevant difference is not age but rather how we describe these events, the stories we tell ourselves about them. Twenty-year-olds don’t think, “Oh, this must be early-onset Alzheimer’s.” They think, “I’ve got too many things to do right now” or “I need to get more than four hours of sleep.” The 70-year-old observes these same events and worries about her brain health. It is not to say that Alzheimer’s- and dementia-related memory impairments are fiction — they are genuine — but every lapse of short-term memory doesn’t necessarily indicate a biological disorder. Like every growth anywhere in the body is not cancer. Alcoholics can have liver cirrhosis, but so can teetotallers! Memory impairment is not inevitable in the absence of brain disease even at an age beyond 80.
Some aspects of memory get better as we age. For instance, our ability to extract patterns, regularities and to make accurate predictions improves over time because we’ve had more experience. We call it grey hair! (This is why computers need to be shown tens of thousands of pictures of traffic lights or cats to be able to recognise them– that is the way face recognition was developed.) If you’re going to get an X-ray, you want a 70-year-old radiologist reading it, not a 30-year-old one—the reason for this is straightforward. The seventy-year-old has seen many more x-rays in his lifetime than the thirty-year-old doctor. He has discussed hundreds of more x-rays, diagnosed many patients. With no brain damage, the doctor can recall from his database. After all, today’s AI systems do the same thing. They are fed massive data and retrieve data based on the query sent. But when doing procedures or surgeries, a 30-year-old may be more adept to using modern equipment than a seventy-year-old doctor.
So how do we account for our subjective experience that older adults seem to fumble with words and names? First, there is a generalised slowing with age — but given a little more time, older adults perform just fine. Then there is a problem regarding bodily functions. Eyesight slowly deteriorates, hearing goes down over a period. Sometimes the balance also a problem. I take a precautionary step of holding the railing while climbing down the steps. All these precautions slow down our other processes like memory access, but it is not because of memory issues.
The older brain must search through astronomical data collected over time. Younger adults search through much smaller data when they try to retrieve things. It’s not that you can’t remember, but you are going through a lot of data; people think that you have slowed down. The studies performed to simulate the young brain, and the old brain show this crowdedness.
Last year during Holi festival, I was passing by the kids who were splashing balloons filled with colour. One of the balloons splashed on me, by mistake. The kids were scared, but the colours reminded me of my childhood when we used to splash balloons on older people purposely. I laughed, took a balloon and threw it on those kids. We all enjoyed it. It is this ability to remember what I used to do 60 years back is easily recalled than what happened six days ago, looks surprising to us.
When I thought about this in peace, I was not surprised. I understood that I am the same person, even today. My thinking has not changed much. I would still like to drink cola, which we would have in childhood, after pinching a coin from home. When I saw the strong sea waves crashing on Marine Drive in Bombay, for the first time, I was thrilled. There are some things that we still enjoy as we did in childhood. But the same landscape of Lonavala may not thrill me so much now because of the familiarity. Then what we need is to reinvent what we love. Go to different places; they have their lovely trees and birds, wind and the flowers. I had fun recently when we had a holiday in the hills of Madikeri in Karnataka. The trees and bushes there emanated a different smell than what I get in Pune.
It is the combination of enjoying new and fresh things that reinvent us. We do slow down a bit, but if we are free of brain diseases, our memory and thinking plus recalling old stuff do not change much.
These new things I remember for months because they are unique but new. And experiencing new things is the best way to keep the mind young, pliable and growing — into our 80s, 90s and beyond.