Understanding Memory Levels and Techniques

1. Higher Human Biology Unit 3A Neurobiology KEY AREA 3A: Memory

2. 3a i) Memory • Memory involves encoding, storage, and retrieval of information • Memories include past experiences, knowledge and thoughts • The brain can capture images of sights, sounds, smells, tactile sensations, and emotions all experiences at one time and retain them as memories • Memory involves 3 interacting levels. All information entering the brain passes through: - Level 1 - Sensory Memory(SM) Level 2 - Short Term Memory(STM) Level 3 - Long Term Memory (LTM) OR discarded

3. 3a ii) Memory Memory involves 3 interacting levels

4. 3b) Sensory Memory Stimuli from the environment are continuously being perceived as sensory images by the brain (visual & auditory input). These impressions are VERY SHORT LIVED (only last for 0.5 seconds for visual images & 2 seconds for auditory images) Only selected images and sounds are encoded into short-term memory

5. 3c i) Short-term Memory (STM) Short-term memory (STM) only holds a limited amount of information – usually about 7 items at one time (memory span), and the items are only held for a short time. The information is either:- Transferred to Long Term Memory Lost by displacement (pushing out old information by new info) Lost by decay (breakdown of memory trace when neurons are activated)

6. 3c ii) Short-term Memory(STM) – Chunking The capacity of the Short- term memory can be improved by chunking Chunking is when several units are put together to create one meaningful unit e.g. the numbers 86015 are easier to remember as 01856 (code for Kirkwall) as you are already familiar with it! Chunking can improve STM Lists of letters to remember :- Set 1 - ICL, TPT, OML, MVM, EZQ, CPG, UPR, MCA, RPA, Set 2 – HIV, FBI, UFO, BBC, KGS, RIP, USA, VAT, NYC Which set is easier to remember? Why? “Learning is not just remembering! It is about making sense of something!”

7. 3c iii) Short-term Memory(STM) – Serial Position Effect The Serial Position Test 1. Show 20 objects one at a time to an individual 2. Each object is observed for 5 seconds 3. After the last object, the subject has to write down as many of the objects that they can remember, in any order Try the KGS Serial Position Effect Test!

8. 3c iii) Short-term Memory(STM) – Serial Position Effect The Serial Position Effect Recall is best for items shown at the end of the test, followed by items shown at the start. Items shown in the middle of the test are poorly remembered. This is due to the items at the beginning of the test have been transferred into the LTM, and items at the end are still held in the STM

9. 3c iv) Short-term Memory(STM) – Rehearsal Rehearsal involves repeating information over and over again in order to help you to memorise This process helps to maintain items in the STM and therefore increase the chances of transfer into Long-term memory and is the most effective method to use for learning Rehearsal is used to help pass your Highers, pass your driving test! Investigation Opportunity Effect of rehearsal on motor memory skills

10. 3c V) Short-term Memory(STM) – Working memory STM can also process data, to a limited extent, as well as store it This enables simple cognitive tasks to be carried out e.g. you have been asked to think of all the pieces of furniture containing drawers that are present in your home and then calculate the total number of drawers. To do this you form a mental image of your home, as you come to each relevant piece of furniture, you employ your working memory to count the number of drawers and add this value to the running total in your STM

11. 3d i) Long-term Memory(LTM) Long-term memory (LTM) is thought to be able to hold an unlimited amount of information for a long time Information is constantly being transferred between the STM and the LTM If during STM the item is encoded, then this item will be transferred for storage in the LTM. LTM will then be able to retrieve the item Successful transfer of information from STM to LTM is promoted due to rehearsal, organisation and elaboration of meaning

12. 3d ii) Long-term Memory(LTM) Organisation Information that is organised into logical categories is more easily transferred from the STM to the LTM Which list is the easiest to remember?

13. 3d iii) Long-term Memory(LTM)- Rehearsal & Elaboration Encoding: The conversion of one or more nerve impulses into a form that can be received & held by the brain and retrieved later from the STM or LTM Shallow encoding: e.g. Rehearsal Information encoded by rehearsal (repetition) Example: Names of people in the class Deeper encoding e.g. Elaboration of meaning Elaboration involves analysing the meaning of the item to be memorised and taking note of features and properties Information encoded by associating it with other information such as a meaning or linking it with previous memories Example: Name of people in class & what they look like Deeper encoding leads to improved information retention

14. 3d iv) Long-term Memory(LTM) – Retrieval Classification of information in the LTM The LTM stores information in distinct categories e.g. types of fruit, colours, numbers, names of family members Retrieval of items in the LTM LTM contains a vast store of items constantly being revised, reorganised and enlarged as new materials flows in. A ‘search’ is required to retrieve information from the LTM. The search is aided by contextual cues- signal or reminder of how the information was encoded into the LTM including the conditions or circumstances that were present at the time Contextual cues somehow trigger an impulse through a “memory circuit” A memory whose encoding in the LTM is accompanied by unusual, emotional or dramatic events (e.g. a wedding day) possess powerful contextual cues. These enable the experience to be retrieved and recalled clearly throughout life

15. KEY AREA 3A QUESTIONS: • Testing your knowledge pg 246 Q 1-4 • What you should Know pg 246 Q 8-14