Memory and attention

How memory works, and everyday ways to keep it sharp

4 min read

The short answer: memory is not one thing but several systems working together: a small, short-lived "working memory" for what you are doing right now, and a large long-term memory for everything you keep. Forgetting is normal, and some changes with age are normal too. Well-studied habits such as good sleep, regular exercise and testing yourself rather than re-reading make a real difference.

Important: this article is general information, not medical advice. If you or the people close to you are worried about your memory, talk to a doctor.

The different kinds of memory

Working memory: what you hold in mind right now

This is the mental notepad you use to remember a phone number while you dial it, or to follow a conversation. It is small: most people can hold around 4 meaningful chunks at once, or about 7 single digits. It is also short: without repeating, things fade within seconds.

Long-term memory: what you keep

This is where information goes when it is stored for minutes, years or a lifetime. It includes:

• events you lived through (your last birthday);
• facts and knowledge (the capital of France);
• skills that become automatic (riding a bike, typing).

How a memory is made

Remembering has three steps, and problems can happen at each one:

1. Taking it in (encoding). You can only remember what you paid attention to. Many "forgotten" names were never really taken in.
2. Keeping it (storage). New memories are fragile at first. Much of the strengthening happens during sleep.
3. Finding it again (retrieval). The memory may be there but hard to reach, as in the familiar "it's on the tip of my tongue" feeling.

Why we forget

Forgetting is part of how memory is meant to work: it clears out what we do not need. Without review, most new information fades quickly, especially in the first day or two. Things are remembered better when they are meaningful, connected to what you already know, emotional, or reviewed several times.

What normally changes with age

With age, many people notice that:

• recalling names and words takes a little longer;
• it is harder to do several things at once;
• learning new information takes more repetition.

These changes are common and do not usually affect everyday independence. Knowledge, vocabulary and well-practiced skills often stay strong or even grow.

Everyday ways to keep your memory sharp

These are among the best-supported habits:

• Sleep well. Sleep helps turn new memories into lasting ones. Regular, sufficient sleep is one of the simplest things you can do.
• Move your body. Regular aerobic exercise, such as brisk walking, is good for the brain. In one study, a year of walking three times a week increased the size of a brain area important for memory in older adults.
• Test yourself instead of re-reading. Trying to recall something strengthens memory more than reading it again. Quiz yourself, or explain it to someone.
• Space it out. Reviewing a little on several days works better than cramming once.
• Pay attention on purpose. When you meet someone, say their name back and connect it to something. Put keys in the same place every time.
• Stay socially and mentally active. Conversations, hobbies and learning new things keep the mind engaged.
• Look after your general health. Hearing, eyesight, blood pressure and mood all affect memory. Your doctor can help with these.

When to talk to a doctor

Talk to a doctor if memory problems are new, getting worse, or affecting daily life. For example: getting lost in familiar places, repeating the same questions, struggling with things you used to do easily, or friends and family noticing changes. Many causes of memory problems can be treated, and a doctor is the right person to look into them. No online test can tell you whether you have dementia.

Track your own memory

The Happy Me Memory and attention assessment uses three short exercises (word recall, number sequences and picture pairs) with different material each time, so you can follow your own scores over time. It takes about 10 minutes, is free, and needs no account. It is a wellness check, not a medical assessment: it cannot detect dementia. If you are worried about your memory, talk to a doctor.

Take the free memory test

Sources

• Cowan, N. (2001). The magical number 4 in short-term memory: A reconsideration of mental storage capacity. Behavioral and Brain Sciences, 24(1), 87–114.
• Miller, G. A. (1956). The magical number seven, plus or minus two. Psychological Review, 63(2), 81–97.
• Diekelmann, S., & Born, J. (2010). The memory function of sleep. Nature Reviews Neuroscience, 11(2), 114–126.
• Roediger, H. L., & Karpicke, J. D. (2006). Test-enhanced learning: Taking memory tests improves long-term retention. Psychological Science, 17(3), 249–255.
• Erickson, K. I., et al. (2011). Exercise training increases size of hippocampus and improves memory. Proceedings of the National Academy of Sciences, 108(7), 3017–3022.
• Cepeda, N. J., Pashler, H., Vul, E., Wixted, J. T., & Rohrer, D. (2006). Distributed practice in verbal recall tasks: A review and quantitative synthesis. Psychological Bulletin, 132(3), 354–380.