Despite this, memory is generally poorly understood, which is why many people say they have ‘bad memories’. That’s partly because the analogies we have to hand—like that of computer memory—are not helpful. Human memory is vastly more complicated and quirky than the memory residing in our laptops, tablets or phones.
Here is my 10-point guide to the psychology of memory (it is based on an excellent review chapter by the distinguished UCLA memory expert, Professor Robert A. Bjork)
1. Memory does not decay
Everyone has experienced the frustration of not being able to recall a fact from memory. It could be someone’s name, the French for ‘town hall’ or where the car is parked.
So it seems obvious that memories decay, like fruit going off. But the research tends not to support this view. Instead many researchers think that in fact memory has a limitless capacity. Everything is stored in there but, without rehearsal, memories become harder to access. This means it’s not the memory that’s ‘going off’ it’s the ability to retrieve it.
But what on earth is the point of a brain that remembers everything but can’t recall most of it? Here’s what:
2. Forgetting helps you learn
The idea that forgetting helps you learn seems counter-intuitive, but think of it this way: imagine if you created a brain that could remember and recall everything. When this amazing brain was trying to remember where it parked the car, it would immediately bring to mind all the car parks it had ever seen, then it would have to sort through the lot.
Obviously the only one that’s of interest is the most recent. And this is generally true of most of our memories. Recent events are usually much more important than ones that happened a long time ago.
To make your super-brain quicker and more useful in the real world you’d have to build in some system for discounting old, useless info. In fact, of course, we all have one of these super-brains with a discounting system: we call it ‘forgetting’.
That’s why forgetting helps you learn: as less relevant information becomes inaccessible, we are naturally left with the information that is most important to our daily survival.
3. ‘Lost’ memories can live again
There’s another side to the fact that memories do not decay. That’s the idea that although memories may become less accessible, they can be revived.
Even things that you have long been unable to recall are still there, waiting to be woken. Experiments have shown that even information that has long become inaccessible can still be revived. Indeed it is then re-learned more quickly than new information.
This is like the fact that you never forget how to ride a bike, but it doesn’t just apply to motor skills, it also applies to memories.
4. Recalling memories alters them
Although it’s a fundamental of memory, the idea that recall alters memories seems intuitively wrong. How can recalling a memory change it?
Well, just by recalling a memory, it becomes stronger in comparison to other memories. Let’s run this through an example. Say you think back to one particular birthday from childhood and you recall getting a Lego spaceship. Each time you recall that fact, the other things you got for your birthday that day become weaker in comparison.
The process of recall, then, is actually actively constructing the past, or at least the parts of your past that you can remember.
This is only the beginning though. False memories can potentially be created by this process of falsely recalling the past. Indeed, psychologists have experimentally implanted false memories.
This raises the fascinating idea that effectively we create ourselves by choosing which memories to recall.