Session 6: Models of Memory. Evaluate two models or theories of one cognitive process with reference to relevant research studies What the command term

Cognitive Level of Analysis

Session 6: Models of Memory

Evaluate two models or theories of one cognitive process with reference to relevant research

studies

Today’s learning outcome

What the command term means…Evaluate: Make an appraisal by weighing up the strengths and limitations.

We will be evaluating TWO MODELS OF MEMORY these have been developed by cognitive psychologists to explain how memory works

The two models of memory you will learn are:

1. Multi-store Model (Atkinson & Shiffrin, 1968)2. Working Memory Model (Baddeley and Hitch, 1974)

MODELS OF MEMORY

Definition: The mental processes involved in storing and retrieving information

Essential Questions:

How does our mind organise data? How do psychologists study memory?

Memory

Model 1: The Multi Store ModelAtkinson and Shiffrin (1968)

One of the first models to give an overview of basic structure of memory

Inspired by computer science Although model seems simplistic today it

did spark off the idea of humans as information processors

Has been one of most influential models attempting to describe memory system

Model 1: Multi-store model of memory (Atkinson and Shiffrin1968)

Based on assumption that memory consists of a number of separate stores and that memory is sequential


Memory stores are structural components that include control processes (e.g. attention, coding and rehearsal).

Rehearsal ensures the transfer of information from short term memory to long term memory


Sensory Memory• Registers sensory information and stores it for around 1-4

seconds• Information in sensory information is modality specific (i.e.

Related to different senses)• Only a small amount of sensory memory will be transferred

to STM store• This depends on whether or not it is attended to


Short Term Memory (STM)• Has limited capacity (around 7 items)• Limited duration (around 6-12 seconds)• Information in STM is transferred to LTM if rehearsed, if not it is lost


Long Term Memory (LTM)• Believed to be of indefinite duration• Potentially unlimited capacity


Evidence for Multi-Store Model: Serial Position

EffectAn investigation into short term memory

I am about to carry out an experiment into the serial position effect in memory.

You will be shown a series of words and asked to remember them. Then, you will be asked to recall as many of the words as you can. The experiment should not take longer than five minutes.

You do not have to take part if you don’t want to. If you take part but do not want your recall made public, I will respect your wishes. The results are completely anonymous.

Is there anybody who does not wish to take part?

Brief

You will need some paper and pen to write down the words you remember.

When we start, you will see a series of slides with one word on each slide

After the last slide, you will be asked to recall as many of the words I have presented in any order.

Any questions?

Standardised Instructions

Mask

Wine

Coat

Book

Music

Stamp

Hinge

Horse

Goldfish

King

Printer

Clock

Knife

Carpet

Kite

Phone

Pepper

Arrow

Jelly

Van

Newspaper

Square

Cup

Flower

Shoe

Bed

Kitten

Diamond

Gun

Tree

Now write down as many of the words that you can remember, in any order

You will have 2 minutes for this

Recall

Thank you for taking part in the experiment.

The theory is that words at the beginning and end of the list are more likely to be recalled than words from the middle of the list.

Debrief

Let’s tally up which ones you remembered

Evidence of Multi Store ModelThe Serial Position Effect•Believed to be linked to rehearsal i.e. People rehearse things to remember them•Serial position effect suggests people remember things better if they are eitherthe first (primacy effects) or the last (recency effect) item in a list to remember

Evidence of Multi Store Model

The Serial Position Effect: Glanzer and Cunitz (1966)Aim: to investigate serial position effect in free recallProcedure: laboratory experiment where participants heard a list of items and then immediately had to recall them in any orderResults: Participants recalled words from beginning and end of list the best. Results showed a U-shapedcurveIf participants were givena filler task just after hearing words the primacy effect disappearedand the recency effect remained

Evidence of Multi Store Model

The Serial Position Effect: Glanzer and Cunitz (1966)

The recency effect could be due to words still being active in STMRehearsal could be a factor in transferof information into LTM

Evaluation:Study supports idea of multiple stores(STM and LTM).Controlled lab experiment with highly controlled variables but there is no random allocation of participants to conditions so it is not a true experimentMay be issues with ecological validity

Evidence of Multi Store ModelCase studies of individuals with amnesia due to

brain damage

•Amnesia is caused by damage to the hippocampus and related networks involved in storage of new memories•MRI scans show that HM had severe damage to hippocampus which is critical of storage into LTM•HM could store new procedural memories but was unable to store any explicit new memories.•This is evidence that memory contains different systems

Strengths Model pioneered the new approach to memory

where humans are seen as information processors

Model’s conceptualisation of memory as multi-stored is supported by research

The overall model has been modified, for example, Baddeley and Hitch (1974) with their new version of short term memory, the ‘working memory’ model

Evaluation of Multi Store Model

Limitations Model is very simplistic and cannot account for

how interaction between the different stores takes place

Research into encoding of LTM has challenged the single-store version of LTM. It is now accepted that LTM contains several stores (e.g. semantic, episodic, procedural)

Evaluation of Multi Store Model

Atkinson’s and Shiffrin’s (1968)multi-store model was extremely successful in terms of the amount of research it generated.

However, as a result of this research, it became apparent that there were a number of problems with their ideas concerning the characteristics of short-term memory.

Conclusions...

Model 2: The Working Memory ModelBaddeley and Hitch (1974)

Studied the MSM model and believed that the model’s short term memory (STM) store lacked detail

Suggested the working memory model as an alternative to STM

It is a far more complex explanation of STM Model changed view that STM is unitary i.e.

Suggested STM made up of different components LTM as a more passive store that holds previously

learned material for use by the STM when needed.

Model 2: Working Memory Model (Baddeley and Hitch, 1974)


So what’s the difference between STM and working memory??

Seen as an active store used to hold and manipulate information

Originally made up of three separate parts Model been developed over years to include

findings from research- a 4th component, the episodic buffer, was added in 2000


Working memory includes 4 separate components each with specialised function

Supervisory System:1. The Central Executive

Slave Systems:2. The phonological loop3. The visuo-spatial sketchpad4. The episodic buffer (2000)


The Working Memory Model (Baddeley & Hitch, 1974)

Monitors and coordinates other components Modality free so can process information in any modality According to model, most important part of the working memory because it

was in complete control of other components Has ability to store information but its capacity is limited. Allocates data to the subsystems Also deals with cognitive tasks such as mental arithmetic and problem

solving. Decides what working memory pays attention to.

E.G. two activities sometimes come into conflict such as driving a car and talking. Rather than hitting a cyclist who is wobbling all over the road, it is

preferable to stop talking and concentrate on driving. The central executive directs attention and gives priority to particular activities.

Working Memory Model: Central Executive

Baddeley uses metaphor of a company boss to describe central executive Company boss makes decisions about which issues deserve attention and

which should be ignored. They also select strategies for dealing with problems, but like any person in

the company, the boss can only do a limited number of things at the same time. The boss of a company will collect information from a number of different sources.

If we continue applying this metaphor, then we can see the central executive in working memory integrating (i.e. combining) information from two assistants (the phonological loop and the visuo-spatial sketchpad) and also drawing on information held in a large database (long-term memory).

However, despite its importance in the working-memory model, we know considerably less about this component than the subsystems it

controls.

Working Memory Model: Central Executive

Read the digits below to yourself and then, immediately, close your eyes and try to remember the digits, silently. After a few seconds, repeat them aloud.

7594132

Working Memory Model: The Phonological Loop

7594132

How did you accomplish the task? Many people report that when they read the digits silently they

“hear” them in their head, in the sound of their own voice. Then, when their eyes are closed, they “rehearse” the sounds,

repeating the words silently to themselves. The subjective experience seems to be of speaking the digits “in

your mind.”

Does this experience match yours?

The idea that verbal working memory involves both a “mind’s ear” (that heard the digits when you read them) and a “mind’s voice” (that repeated them in rehearsal) is central to current thinking

about the phonological loop.


Deals with spoken and written material

Divided into 2 further components:

1. Phonological Store (“inner ear)” – Linked to speech perception Holds information in speech-based form (i.e. spoken words) for 1-2 seconds. Spoken words enter the store directly. Written words must first be converted into an articulatory (spoken) code before they can enter the phonological store.

2. Articulatory control process (“inner voice”) – linked to speech production) acts like an inner voice rehearsing information from the phonological store. It circulates information round and round like a tape loop. This is how we remember a telephone number we have just heard. As long as we keep repeating it, we can retain the information in working memory

◦ Phonological store ( holds words heard)◦ Articulatory process ( linked to speech production, rehearses info from

phonological store aloud in our heads)


How many windows are there in the front of your house?

Where is the door?

Can you draw it?

Working Memory Model: Visuo-spatial sketchpad

You probably find yourself picturing the front of your house and counting the windows. An image has been retrieved from LTM and pictured on the visuo-spatial sketchpad.


The “inner eye” Visual = what things look like Spatial = relationships between things

Handles visual and spatial information from either sensory memory (visual information) or from LTM (images)

The eyes are used to store and manipulate visual and spatial information such as remembering colours or shapes.

Plays an important role in helping us keep track of where we are in relation to other objects as we move through our environment

The sketchpad also displays and manipulates visual and spatial information held in long-term memory.


26 years after the original working memory model, Baddeley added this third slave system as he realised model needed a more general store.

Limited capacity temporary storage system Assumed to be controlled by the central executive through conscious

awareness Handles information in various modalities Resembles the concept of episodic memory

Links together every piece of information from all other elements of working memory with further information relating to time and order. This process

enables memories to be prepared for episodic LTM storage.

Working Memory Model: The Episodic Buffer

There is evidence of working memory in dual tasks experiments

WM Model assumes there is a division of tasks between the different systems according to modality

The working memory model makes the following two predictions for dual task experiments:

◦ 1. If two tasks make use of the same component (of working memory), they cannot be performed successfully together.

◦ 2. If two tasks make use of different components, it should be possible to perform them as well as together as separately.

Results from Dual task experiments support the view that the phonological loop and the sketchpad are separate systems within working memory.

Evidence of the working model of memory

Baddeley and Hitch (1976)

Aim: To investigate if participants can use different parts of working memory at the same time.

Method: Conducted an experiment in which participants were asked to perform two tasks at the same time (dual task technique) - a digit span task which required them to repeat a list of numbers, and a verbal reasoning task which required them to answer true or false to various questions (e.g. B is followed by A?).

Results: As the number of digits increased in the digit span tasks, participants took longer to answer the reasoning questions, but not much longer - only fractions of a second. And, they didn't make any more errors in the verbal reasoning tasks as the number of digits increased.

Conclusion: The verbal reasoning task made use of the central executive and the digit span task made use of the phonological loop.


Quinn and McConnel (1996) Asked participants to learn a list of words by using either

imagery or rehearsal Task performed on its own or in the presence of a concurrent

visual noise (changing patterns of dots) or concurrent verbal noise (speech in a foreign language)

Results showed learning words by imagery was not affected by a concurrent verbal task but was disturbed by a concurrent visual task

The opposite was found in the rehearsal condition Indicates imagery processing uses visuo-spatial sketchpad

whereas verbal processing uses the phonological loop If 2 tasks used the same component, performance deteriorated Study lends support to different modality specific systems and

the idea of limited processing capacity


Evidence for Phonological Loop

Remember the following words:

Harm

Twice

Calm

Share

Tree

Book

Sun

Four

Key

Short

Now try to recall them!

How many did you get right? Harm Twice Calm Share Tree Book Sun Four Key

Short

And again..recall these:

Association

Representative

Discouragement

Meaningfulness

Suppression

Enhancing

Component

Performances

Forgetting

Damaging

Recall them! How many did you get right this time?

Association Representative

Discouragement Meaningfulness

Suppression Enhancing

Component Performances

Forgetting Damaging

Why?

The phonological loop can offer an explanation of why the word- length effect occurs – the fact that people cope better with short words than long words in working memory (STM).

Evidence for Phonological Loop Word- length effect

It seems that the phonological loop holds the amount of information that you can say in 1.5 - 2 seconds (Baddeley et al, 1975).

This makes it hard to remember a list of long words such as ‘association’ and ‘representative’ compared to shorter words like ‘harm’ and ‘twice’ and therefore inhibits rehearsal of longer words!

Repeat the word ‘the’ whilst looking at the list

Now try again but...

BUT… Word length effect disappears if a person is

given an articulatory suppression task (‘the, the, the’ while reading the words).

The repetitive task ties up the articulatory process and means you can’t rehearse the shorter words more quickly than the longer ones, so the word length effect disappears.

This provided evidence for WMM

The KF Case Study supports the Working Memory Model.

KF suffered brain damage from a motorcycle accident that damaged his short-term memory.

KF's impairment was mainly for verbal information - his memory for visual information was largely unaffected.

This shows that there are separate STM components for visual information and verbal information

KF Case Study

Strengths Researchers today generally agree that short-term memory is made

up of a number of components or subsystems. The working memory model has replaced the idea of a unitary (one part) STM as suggested by the MSM model.

The working memory model explains a lot more than the MSM model. It makes sense of a range of tasks - verbal reasoning, comprehension, reading, problem solving and visual and spatial processing

The KF Case Study supports the Working Memory Model. KF suffered brain damage from a motorcycle accident that damaged his short-term memory. KF's impairment was mainly for verbal information - his memory for visual information was largely unaffected. This shows that there are separate STM components for visual information and verbal information

Working memory is supported by dual task study research and by word-length effect

Brain scans show different areas of the brain are used for visual and verbal tasks which supports the WMM.

Evaluation of the working model of memory

Limitations Central Executive which is still not clearly explained nor understood. Its

functions are unclear and extremely difficult to test. Suggested that it is possible to divide the Central Executive into smaller systems but has thus far failed to positively do so.

Episodic Buffer which was brought into the equation remains a mystery in terms of how it binds together information from the model’s other parts and LTM.

Lieberman criticizes the working memory model as the visuo-spatial sketchpad implies that all spatial information was first visual (they are linked). However, Lieberman points out that blind people have excellent spatial awareness although they have never had any visual information. Lieberman argues that the VSS should be separated into two different components: one for visual information and one for spatial.

Working memory only involves STM so it is not a comprehensive model of memory (as it does not include SM or LTM).

Fails to account for musical memory as we are able to listen to instrumental music without impairing performance on other acoustic tasks.

Evaluation of the working model of memory

Draw your own flow chart for both models of memory

Include some facts for each structural component of memory

Use page 73 of your textbook to help you

Task

Documents

Session 6: Models of Memory. Evaluate two models or theories of one cognitive process with reference to relevant research studies What the command term