Scientists are increasingly discovering that memory’s power lies in processes that don’t resemble a machine at all – it’s much more complex and interesting than a simple photographic record of what has passed. Remembering is a much more active process of construction.
The difficulty is not so much in storing information – getting knowledge into memory – but getting it out again when we need it.
Below is a step-by step explanation of how information is stored and then retrieved.
1. Paying Attention
- Our memory for facts and events starts with paying attention, because strong memories need good inputs of information (visual, auditory and kinesthetic).
- When we focus on something, we encode information in short-term electrochemical signals between billions of networked neurons.
- Holding this information in working memory mostly takes place in the prefrontal cortex, a part of the brain involved in executive function.
- We can retain the information here for a few seconds before it decays, or we can keep refreshing it, but only as long as we don’t get distracted.
2. Long-term Memory
- Information is then transferred to long-term memory by passing through the hippocampus – the area of the brain thought to be the centre of emotion, memory, and the nervous system.
- It works like a sorting office for the brain, storing just enough information to point to and activate the relevant sites in the neocortex, the outer layers of the brain responsible for sensory perception and conscious thought.
- The hippocampus organises the information from different sensory inputs and compares it with earlier memories.
- When we are expected to retrieve new facts, such as in a test, we pass them through the hippocampus again, causing gradual and long-lasting changes in connections within the neocortex.
- Reactivating a memory is likely to strengthen the connections in the neurons and make it easier to recall in future.
4. Quick and Effortless Knowledge
- Eventually, the connections within the neocortex become established so that we can recall the memories that they encode without the intervention of the hippocampus.
- It becomes part of the quick and effortless knowledge base that encompasses things such as meanings of words, general knowledge or social customs.
(Adapted from Tes: ‘Uncovering the Truth about Memory’ by Joseph Lee, March 2016)