Unit 3: Behaviour, Populations and

environmentChapter 29: Localisation of memory

Memory – encoding, storage and retrieval

21/04/23 Mrs Smith Ch25 The Brain 1

Higher Human Biology

Learning Intentions

To examine the workings of the brain and the nervous system and its role in Memory

Success Criteria

Describe the processes of encoding, storage and retrieval

Learning Outcomes

• To learn about the limbic system in relation to memory storage

• To examine the process of memory – encoding, storage and retrieval

• To compare the differences between long and short-term memory and how memory is transferred from STM to LTM

• To find out what causes Alzheimer’s disease at a molecular level

Limbic System

• Memory is the brain’s ability to store information then retrieve it when its needed.

• Different types of memories are associated with different parts of the brain.

Memory

• The receptors in the human sense organs are continuously picking up stimuli and transmitting impulses to the brain.

• This results in sensory images such as visual and acoustic (auditory) impressions being formed in certain areas of the CEREBRUM.

Selective Memory

• However only a fraction of these sensory images become committed to memory, because this process is highly selective.

If our memory was not selective

The mind would become too cluttered with useless information such as every phone number ever used, every musical note of every tune ever heard and so on.

The stages of memory

There are 3 stages in memorising facts and experiences:

•encoding

•storage

•retrieval

1. Encoding1. Encoding• All sensory information, before becoming part

of a memory, must be encoded - be converted to a form that the brain can process & store.

• Sometimes encoding is automatic, other time it requires effort e.g. learning biological terms

There are several ways of encoding information:

• E.g. trying to remember the word for fork in Spanish – “tendor”

• Acoustic – say the word a few times • Visual - visual image of a new word• Semantic - think about the meaning of the word

• To memorise we use techniques such as rehearsal, organisation and elaboration

Examples of Encoding

• Acoustic Coding (most common) – If we memorise a poem, word for word

• Visual Coding (less common)– To remember someone’s face

• Semantic Coding (less common)– To remember the gist of a play or tv programme

Examples of Encoding• The majority of information received by the brain

is acoustic coding (sound). Some is also visual or semantic (meaning).

• To remember a phone number: we usually see it (visual), rehearse it (acoustic) and may place a meaning to it (semantic).

• It is easier to remember items organised into groups or use mnemonics to remember long numbers and lists of names- twit twoo (PIN 2820)- OILRIG- Richard of York gave battle in vain (ROYGBIV)

Storage is the retention of information/memories, over a period of time.

This may last a short amount of time or over the course of a life time.

2. Storage2. Storage

3. Retrieval

• Retrieval is the recovery of the stored material.

• This involves the recall of information which has been committed to either the long-term or short-term memory.

Helping our retrieval skills

Easier to retrieve facts and experiences if we are in the same situation as we were when it was encoded. As this rarely happens, we rely on contextual cues (smell, sound, sight, person etc) to “jog” our memory. Can use visualisation techniques e.g. posters for organic molecules

Change stimulus into a form we can retain.

Store in short term or long term

memory.

Access when required.

ENCODING

STORAGE

RETRIEVAL

Summary

Learning Intentions

To examine the workings of the brain and the nervous system and its role in Memory

Success CriteriaDesign and carry

out an investigation to determine the

memory span for letters or numbers.

Investigating memory span

A person’s short-term memory span can be measured by finding out the number of individual ‘meaningless’ items which they can reproduce correctly in order immediately after seeing and hearing them once.

Memory Span Con’ tRemembering objects once covered

e.g. Recalling number series:

741283546279584153265843796124892

TASK: Write numbers 3 to13 below each other. I will read out some numbers, after I read out the last digit of each series, I will signal you to lift your pencil and write down the digits you have just heard. Place your pencil down and I will begin the next series

Memory ExperimentSeries Number of

digits in series

Number of pupils who remember series

correctly

741 3

2835 4

46279 5

584153 6

9082637 7

16136209 8

592403517 9

8076148362 10

78501942493 11

512367509308 12

6821496708754 13

Memory experiment results

• The tester will check the responses against the first list.

• The procedure is repeated at least twice using different lists.

• Each subjects best overall list is take to represent his or hers memory span.

• When studying a population, such as the class results are pooled and can be graphed.

A false memory

• Horizon Video Part 1 & 2

• http://www.bbc.co.uk/sn/tvradio/programmes/horizon/broadband/tx/memory/false/

Chunking is the grouping information into one large unit made of smaller units. This increases memory span.

The effect of ‘Chunking’ on Memory Span!

e.g. 01236 is the telephone code for Cumbernauld

so makes it easier to remember local phone numbers, allowing us to remember more than we could without chunking.

• STM is only capable of holding about 7 items at once ± 2.• Short-term memory can be increased by chunking.

Splitting up information that needs to be remembered into chunks (bite sized portions)

• Trying to remember the following telephone nos.:

012369871914 (12 items)01236 987 1914

Cumbernauld (3 items) year First

Area World War

Code began

1 item 1 item

5 items

Memory Span – Chunking Con’t

Learning Intentions

To examine the workings of the brain and the nervous system and its role in Memory

Success CriteriaExplain the

process involved in transferring

information between short and long term

memory

Different Levels of Memory

Continuous flow of information from environment

Selected sensory images transferred

Some images transferred

Short lived: Most sensory

images quickly forgotten

Many items

forgotten

Brain constantl

y forming sensory images

1.Short term

memory

limited capacit

y -7 items

2.

By• Rehearsal• Organisation• Elaboration of meaning

3.Long term

memory

Unlimited capacity

Level 1 Memory

• Stimuli from the outside world are continuously being perceived as sensory images by the brain.

• These impressions are very short-lived.– 0.5 secs for Visual– 2 secs for Auditory

• Only a few of these are selected and transferred to level 2.

Level 2 Short Term Memory (STM)

• Most info encoded into this second level consists of visual and auditory images.

• Used when reading. Allows us to remember words for a few seconds so we understand a sentence.

• Has very limited capacity – approx 7 items so lists longer than approx 8 items almost impossible to remember without specialised techniques (e.g. Chunking)

Level 2 Short Term Memory (STM)

• Not only is STM limited in capacity (7 items), the items are held for only for a short-time (approx 30 seconds).

• During this 30 secs retrieval is very accurate. • STM is constantly bombarded by new

information so when extra information added, other items are displaced.

• After the 30 secs they are either transferred to level 3 or displaced and forgotten.

Homer explains his STM“How is education supposed to make me feel smarter? Besides, every time I learn something new, it pushes some old stuff out of my brain. Remember when I took that home winemaking course, and I forgot how to drive?”

Level 3: Long-term memory

• To retain info for any length of time, it must be transferred to LTM – long term memory.

• This system is thought to hold an unlimited amount of information.

• During encoding the items are organised into categories such as facts, episodes, skills, habit etc.

• These are then stored for a long time even permanently.

Transfer from STM & LTMRequires a conscious effort: Transfer methods...

1. Rehearsal - repetition

2. Organisation - grouping information into related groups or categories.

3. Elaboration of meaning - Analysis of the meaning of the item.

Task: Torrance-TYK pg 236 Qu 1-3

21/04/23 33Mrs Smith Ch25 The Brain

Rehearsal• Rehearsal is repeating something (silently

or out-loud), over and over again.

• Extends length of time held in STM and facilitates transfer to LTM

Rehearsal: Study tip

• Research shows that students who regularly stop and rehearse what they are reading (and trying to learn) are much more successful at committing the information to memory than students who read continuously and resist taking rehearsal breaks.

• Several short rehearsal breaks are more effective than one long rehearsal at the end of a marathon learning session.

Serial position effect

• Can remember objects at start of a series (PRIMARY EFFECT) as there has been time for rehearsal so it is transferred to LTM.

• Can remember objects at end due to objects still being in STM (RECENT EFFECT)

When shown a group of similar objects, one after the other, then asked to write down as many as possible in any order…

The images / words in the middle are pushed out or displaced from

the STM

Serial Position Effect

…but it is difficult to remember the ones in the middle because our short-term memory is crowded and so did not allow the transfer to long-term memory.

If it is a very unusual or favourite item (e.g. Jeans) it can sometimes be recalled no matter what its position.

In an investigation into the serial position effect, the recency effect causes items at the end of the list to be recalled , whilst the primacy effect helps recall of items at the start of the sequence.

Serial Position Effect

Elaboration of meaning aids transfer to long-term memory.

Organisation• Grouping items in an organised way increases

their chance of being successfully transferred from the short-term to long-term memory.

• Organised groups have contextual cues (hints) which help the retrieval of information from the long-tem memory.

• So organisation helps the transfer of info in both directionsOrganisation – grouping information into

related groups or categories.

Short-term

memory

Long-term

memory

Horizon clip on cues: Video 1http://www.bbc.co.uk/sn/tvradio/programmes/horizon/broadband/tx/memory/senses/

Past Paper MCQ 25

Q. Which of the following best describes memory?

R. The total memory capacity of the brain

S. The time taken to learn a piece of information

T. The storage capacity of the short-term memory

U. The capacity to store information in long-term memory

Answer: Past Paper MCQ 25

Q. Which of the following best describes memory?

R. The total memory capacity of the brain

S. The time taken to learn a piece of information

C. The storage capacity of the short-term memory

D. The capacity to store information in long-term memory

Elaboration of MeaningAnalysis of the meaning of the item to be

memorised and finding out more about it to make it more meaningful.

Short-term memory

Long-term memory

e.g. making a mind-map of all the information you know helps you learn by elaboration of meaning

This allows more connections (more contextual cues) so more ways to retrieve the information.

Classification of information in the LTM

• The system of storage in the LTM in analogous to a filing cabinet of unlimited capacity, organised into distinct categories of information.

• As items are encoded and transferred to the LTM, they are classified and filed in appropriate section(s).

Retrieval of Items from the LTMThe LTM contains a vast and permanent store of remembered experience which is constantly being revised, reorganised and enlarged as new material flows into it.

When a piece of information needs to be called up and retrieved from the LTM, a search is mounted. This is aided by contextual cues.

It is thought a contextual cue somehow triggers off an impulse through a ‘ memory circuit’.

The more powerful the contextual (e.g. A wedding day) the more easily the experience can be retrieved.

Lapses in memoryOnce the information has been transferred to the LTM, it is stored permanently, In theory that means that it is never forgotten, so how can failure to recall some item that was once very well known be explained?

Sometimes we find it hard to remember if the:• Contextual cues are weak or incomplete.• Memory has not been retrieved for a long time.

Tip of the tongue state.• The individual lacks sufficient

contextual cues to recall the required information.

• However the person is armed with a sufficient number of cues to narrow the search and retrieve some related information.

• Slowly the cues lead to the required information and the information suddenly appears in the conscious mind.

Tricks used to aid memory

• Rhymes e.g. ‘30 days has September….’

• Memorise simple sentence, with the first letter of each word representing something to be remembered

• Forming bizarre associations e.g. objects in a room – linked to a list of things to remember

Mnemonic Devices

ed

range

ellow

reen

lue

ndigo

iolet

R

O

Y

G

B

I

V

Mnemonic Devices

Task: Torrance-TYK pg 239 Qu 1-4

21/04/23 51Mrs Smith Ch25 The Brain

Task: Torrance AYK pg240/241 Qu’s 1-6

21/04/23 52Mrs Smith Ch25 The Brain

What you should know Ch28-29Cloze pg 241-242

SQA Essay Questions 2010 (1A)

21/04/23 Mrs Smith Ch25 The Brain 54

SQA Essay Questions 2007 (1B)

21/04/23 Mrs Smith Ch25 The Brain 55

SQA Essay Questions 2004 (1A)

21/04/23 Mrs Smith Ch25 The Brain 56

There seems to be one of these essays every 3 years (2004, 2007, 2010). I wonder if there will be one in 2013????