Memory is the way that we process and store the information which allows us to function as part of the world. It is so integral to our identity and our well-being that if we lose all our memories, we die. But memory can also be notoriously fickle. Two people won’t necessarily remember the same event in the same way. And memory gets worse as we age. There are a number of age-related memory diseases such as Alzheimer’s and Parkinson’s. So how exactly does memory work?
Memory – everything that makes up who you are and what you know – is based on electrical and chemical signals between brain cells. The essence of a human being can be distilled into electricity (action potentials) and chemicals (neurotransmitters).
The brain is made up of about 85 billion neurons. These transmit signals to one another via connections called synapses. There are roughly 100 trillion synapses in the human brain. Memory is stored as strengthening of synapses. When two neurons are stimulated at the same time, this can trigger a long lasting increase in signal transmission between these two cells. This is called long term potentiation and is the basis of memory. This is why it is easier to remember something that you practice or remember often than something that you haven’t thought of in years. So with memory it really is a matter of use it or lose it.
The amazing thing is that connections between neurons are constantly changing as we experience and learn new things. In fact new neurons are being made all the time and these have to be integrated into the existing circuits. Yes we still don’t lose most of our memories. The human brain is so cool.