“Where did I have my key for the last time?” You spend a hundred days of your life searching. To glasses, wallets or keys. You try to remember where you last saw it. Why did not you remember that? To understand that, you first need to know something about memory.

Your memory is more than a card index with information. You not only store facts, but all your senses record memories. How something smells, tastes, feels, sounds. All these impressions are inextricably linked. That is why a lot of memories come to mind when you suddenly smell the soap that your granny always used. And undoubtedly you know how you felt when you played with your grandparents.

Grandmother Cell

To understand how information is stored, you need to know a bit about how the brain works. There are billions of nerve cells (neurons) in the brain that can communicate with each other with countless connections.

In the past it was thought that every memory is in a separate nerve cell. There would be such a thing as a ‘Grandmother cell’. The memory of your grandmother would be in this neuron. If this cell would die, you would not be able to remember your grandmother.

It is not that simple. A memory is in many different places in the brain. You remember things because your brain makes new connections between neurons. If you try to remember something you have to address a whole network of neurons and not a single cell.

Long and short Term

How does that work exactly, remembering information? That happens in three steps. You have to imagine that you get all kinds of sensory information through your environment. Your stimuli come in through your senses . Smells, voices, images, but also impressions from your body such as feelings. In short, a chaotic maze of stimuli.

Your sensory memory stores all those impressions for a moment. But only for three to five seconds. You understand that the sensory memory has a large capacity.

You can not remember all this information. You only focus your attention on what you find important. For example, you try to remember a phone number that you key in on your phone. These numbers come in your short-term memory (working memory). On average, you can keep seven things active in your working memory at the same time. So you can remember the phone number just long enough to turn it. But immediately after you do not know the number anymore. Let alone the next day. You can also use this piece of memory if you try to do a complicated calculation by heart. With this you remember the interim results that you have just calculated. If you remember something in your short-term memory, it does not necessarily end up in your long-term memory.

To store information in the long-term memory (reference memory) you often need to pay more attention to it. Sometimes it is necessary to repeat information more often or to associate it with other things that you already know. A pin code is easier to remember if it is your date of birth. And you already know your date of birth. This makes it easier to go into the long-term memory. In this memory you store facts and events (declarative memory), but also how you have to do something (procedural memory).

Unconsciously Remember

Information in your memory is not all consciously stored. We remembered a lot without knowing it. We call this the implicit memory. This is how we think we no longer see advertisements and advertisements. We pay no conscious attention to it and can not even remember which advertisements were on television. Yet we generally buy more often the product that has recently been promoted.