How is information stored as memory, and how does it move from short-term to long-term memory?
The memory system, including sensory memory, short-term memory and long-term memory, the limited capacity and span of short-term memory, the transfer of information by encoding (rehearsal, organisation and elaboration), and retrieval using contextual and emotional cues.
An SQA Higher Human Biology answer on memory, covering sensory memory, short-term memory and its limited capacity and span, the role of rehearsal in retaining information, the transfer to long-term memory by encoding through organisation and elaboration, and retrieval using contextual and emotional cues.
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What this dot point is asking
The SQA wants you to describe sensory, short-term and long-term memory, explain the limited capacity and span of short-term memory, explain how rehearsal and encoding transfer information to long-term memory, and describe how contextual and emotional cues aid retrieval.
The three stages of memory
Sensory memory holds all the information coming in from the senses for a very brief moment. Almost all of it is immediately lost, and only the information we pay attention to passes on to short-term memory. This filtering stops us being overwhelmed by every sight and sound.
Short-term memory
Because short-term memory is so limited, information not rehearsed or processed further is quickly lost. Chunking is why a long telephone number is easier to remember when split into groups, because each group counts as a single item.
Transfer to long-term memory
Encoding is far more effective than simple repetition. It is improved by:
- Organisation - arranging the information into a logical structure.
- Elaboration - thinking about the meaning of the information and expanding on it.
- Linking the new information to memories already stored.
Long-term memory has an effectively unlimited capacity and can store information for years. The more deeply information is encoded, the more securely it is stored and the more easily it can be retrieved later.
Retrieval
Retrieval is helped by cues, triggers associated with the memory when it was formed:
- A contextual cue is a feature of the surroundings present when the memory was made (for example, returning to the place where something happened helps you recall it).
- An emotional cue is the mood or feeling linked to the memory, which can bring it back when the same emotion is felt again.
Examples in context
Example 1. Cramming versus understanding. A student who merely repeats facts (rehearsal) may hold them briefly, but a student who organises the material and links it to what they already know (encoding) stores it in long-term memory and recalls it in the exam, showing why deep encoding beats repetition.
Example 2. A smell triggering a memory. A particular smell present during a childhood event can later bring the whole memory flooding back. The smell acts as a contextual cue that aids retrieval of the stored long-term memory.
Try this
Q1. State the approximate capacity of short-term memory in items. [1 mark]
- Cue. About seven items.
Q2. Explain how elaboration improves the encoding of information into long-term memory. [1 mark]
- Cue. Thinking about the meaning of the information and expanding on it links it more deeply, making it more securely stored and easier to retrieve.
Exam-style practice questions
Practice questions written in the style of SQA exam questions on this dot point, with worked answer explainers. The year tag is the paper they imitate, not the source.
SQA Higher 20194 marksDescribe the role of short-term memory, including its capacity and span, and explain how information is transferred to long-term memory.Show worked answer →
A 4-mark answer needs the properties of short-term memory and the transfer to long-term memory.
Short-term memory (STM) holds a small amount of information for a short time. It has a limited capacity, holding only about seven items, and a limited span, holding them for only a short period before they are lost. Its capacity can be increased by chunking, grouping items into larger units.
Information is held in STM by rehearsal (repetition), and is transferred to long-term memory (LTM) by encoding. Encoding is made more effective by organising the information, by elaborating on its meaning, and by linking it to existing memories. LTM then has an effectively unlimited capacity and can store information for a long time.
Award (1) STM holds a small amount briefly, (2) capacity of about seven items and limited span, increased by chunking, (3) rehearsal retains it and encoding transfers it to LTM, and (4) encoding improved by organisation and elaboration, with LTM being large and long-lasting.
SQA Higher 20213 marksExplain what is meant by the encoding and retrieval of memories, and state one type of cue that aids retrieval.Show worked answer →
This is a 3-mark recall and application question.
Encoding is the process by which information is transferred from short-term memory into long-term memory, for example by organising it, elaborating on its meaning, or linking it to what is already known.
Retrieval is the recovery of stored information from long-term memory so that it can be used. Retrieval is helped by cues. A contextual cue is a feature of the surroundings present when the memory was formed, and an emotional cue is the mood or feeling linked to the memory; either can act as a trigger that brings the memory back.
Award (1) encoding transfers information into LTM (with a method named), (2) retrieval recovers stored information, and (3) a named cue such as contextual or emotional cues aids retrieval.
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