How memory works

Memory is the brain’s ability to store information and find it again later. Chemical and electrical changes happen in the brain when new memories are made.

Making and using memories involves three stages: learning new information, storing it, then retrieving it later on. Memory can be affected if any of these stages are disrupted.

• Learning – this is when you take in new information that you want to remember later on. It may involve reading or watching something new several times or linking it to an existing memory. 
• Storing – this is when the information learnt is stored in the brain.
• Retrieving – this is when you find and use the information that has been learnt. For example, remembering a friend’s social media details or their home address. 

Types of memory

Long-term memory

This is information stored over a long time. There are many types of long-term memory.

• Semantic memory – this is memory of knowledge and facts about people, places, and things. For example, recalling that a banana is a yellow fruit, or that Edinburgh is the capital of Scotland.
• Episodic memory – this is memory about events or episodes that have happened. For example, conversations, holidays, or recalling your first day at school. Episodic memories are personal and different for everyone.
• Prospective memory – this is memory for things you have to do in the future. For example, recalling a doctor’s appointment next week, or sending a card for a friend’s birthday.
• Procedural memory – this is memory for skills and how to do things. For example, knowing how to ride a bike, or to tie a shoelace. These tasks often require effort to learn but once learnt are rarely forgotten.

Short-term memory

Sometimes called ‘working memory’ or ‘attention span’, short-term memory is information that is only kept for the length of time you need to use it. 

Most people can usually keep about seven to nine letters, words, or numbers in their mind at once. An example is remembering a telephone number while you dial. 

Because you only need this type of information for a short time, your brain doesn’t store it. This type of information is easily forgotten unless we actively try to store it in our memory. 

Epilepsy Society is grateful to Professor Sallie Baxendale, Consultant Neuropsychologist, UCLH, London and Professor of Clinical Neuropsychology, University College London, who reviewed this information.

Information updated: March 2023