Do you remember what you had for breakfast, the colour of your friend’s eyes, your holiday last year, your 5 times table, the words to your favourite song, how to ride a bike? All these are memories that have been processed and encoded over time. Memory is the storage component of learning: whether this is how to perform a particular action, such as swimming, knowing how to read, or remembering how to solve addition problems.
There are generally thought to be three types of memory: sensory, working memory, and long term memory.
The process of memory begins with encoding, then proceeds to storage and, eventually, retrieval. However, the process can go wrong at any stage: information may fail to register (be attended to!), fail to be processed, and/or there can be failure to retrieve information (see above).
To properly encode a memory, you must first be paying attention. The sensory memory filters out irrelevant, unnecessary information coming in from our senses. Information is passed from sensory memory into working memory by attention.
Short-term memory has a fairly limited capacity; it can hold about seven items for no more than 20 or 30 seconds at a time. You may be able to increase this capacity by using various memory strategies. For example, a ten-digit number such as 8005840392 may be too much for your working memory to hold. But divided into chunks, as in a telephone number, 800-584-0392 may actually stay in your working memory long enough for you to dial the telephone. Likewise, repeating information can also be helpful. However, any task which uses the same modality (e.g. words/numbers) can produce complete interference and disrupt the encoding of information. For example, trying to learn a list of words for spelling, whilst listening to the radio will make the task much more difficult.
Long Term Memory
Important information is gradually transferred from short-term memory into long-term memory. The more the information is repeated or used, the more likely it is to eventually end up in long-term memory, or to be “retained.” Unlike sensory and short-term memory, which are limited and decay rapidly, long-term memory can store unlimited amounts of information indefinitely.
Episodic memory represents our memory of events and experiences. It is from this memory that we can reconstruct the actual events that took place at a given point in our lives. Semantic memory is a structured record of facts, concepts and skills that we have acquired. The information in semantic memory is derived from that in our own episodic memory, such that we can learn new facts or concepts from our experiences.
Long-term memory processes
There are three main activities related to long term memory: storage, deletion and retrieval.
- Storage: Information from short-term memory is stored in long-term memory by rehearsal. The repeated exposure to a stimulus or the rehearsal of a piece of information transfers it into long-term memory.
- Deletion: mainly caused by decay and interference.
- Retrieval: there are two types of information retrieval: recall and recognition. In recall, the information is reproduced from memory. For example, knowing your address. In recognition, you need a prompt to trigger the memory, or may need the information presented again before recognition takes place. For example, when struggling to remember someone’s name, being told the beginning letter, or where/when you first met them may trigger the retrieval of the correct name; or being told the name will trigger recognition.