Chapter 6: Memory. This knowledge includes: Comparison of models for explaining human memory: Atkinson-Shiffrin’s multi-store model of memory including

UNIT 3 – AREA OF STUDY 2:

MEMORYChapter 6: Memory

STU

DY

DES

IGN

, 20

10

- 20

14

This knowledge includes:Comparison of models for explaining human memory: Atkinson-Shiffrin’s multi-store model of memory including

maintenance and elaborative rehearsal, serial position effect and chunking

Alan Baddeley and Graham Hitch’s model of working memory: central executive, phonological loop, visuo-spatial sketchpad, episodic buffer

levels of processing as informed by Fergus Craik and Robert Lockhart

organisation of long-term memory including declarative and episodic memory, and semantic network theory

Neural basis of memory: role of the neuron in memory formation informed by the

work of E. Richard Kandel roles of the hippocampus and temporal lobe consolidation theory memory decline over the lifespan amnesia resulting from brain trauma and

neurodegenerative diseases including dementia and Alzheimer’s disease

UNIT 3 – AREA OF STUDY 2: MEMORYASSESSMENT TASKS

S/N Work Requirements Glossary – due 15th May, 2012 Workbook which includes the learning activities from

textbook as per the slides and completed activities/tasks given by your teacher (Min. 80% complete) – due 15th May, 2012 or earlier

90% attendance rate

SACs ERA

Week 3 (approx.) /30 marks

Test Week 8 (approx.) /20 marks

NoteIf you are away during a SAC – you MUST hand in an original

medical certificate in order to re sit the SAC.

This is a VCCA requirement, and parents or students who only

phone or email do not satisfy this requirement, and if a medical certificate is not produced, a

score of 0 will be given

CHAPTER 6 – WHAT’S COMING UP? Defining memory Models for explaining human memory- The Atkinson-Shiffrin multi store model- Sensory memory- Short term memory- Craik & Lockharts levels of processing framework- Braddeley & Hitch’s model of working memory- Long Term memory- Serial position effect Neural basis of memory- Role of the neuron in memory formation - Role of hippocampus & temporal lobe - consolidation theory- Amnesia resulting from brain trauma & neurodegenerative

diseases- Memory decline over the lifespan

WHO REMEMBERS ??

MODELS OF MEMORY

How is information processed?

Memory systems

Memory is not a ‘single organ’ or a single ‘thing’, rather it consists of a collection of complex interconnected and interacting systems

We do not have a memory, but we have different memory systems which share a common function of:

our perceptual systems, eg vision are constantly inputting information, however the brain must work out what to attend to, process and store in memory, and what not to!

storing information(learned through

experience)

retrieving the information (when needed)

Processing different information

Storing information (in different ways & types of

information)

DEFINING MEMORY

Memory is often defined as the storage and retrieval of information acquired through learning.

the existence of memory indicates that learning has occurred and the memory is the internal record or representation of an event &/or experience.

Memory is also defined as requiring and as information processing (think… like a computer)

Memory as information processing - Encoding – converting information to a useable form Storage – retaining information in memory Retrieval – information recovered from memory

when needed All three processes are required and if any one is not

included, the memory will not form. (see fig 6.4 on page 291)

Memory as an info-processing system

Memory is an active (uses energy) information-processing system that: Receives, Organises Stores &recovers information

Memory actively alters and organises information, then stores it so that it can be easily retrieved when needed

There are 3 key processes involved in these systems. If any of these processes fail, memory will fail

An additional aspect of the Atkinson & Shiffrin human multi store model included:

Structural features & Control processes.

Incoming sensory input

• Info is converted for storage

Encoding• Info is

retained in brain

Storage• Info is

recovered when needed

Retrieval

MEMORY LIKE A COMPUTER ????

Encoding

Storage

Retrieval

= hitting the letters on the key board -> it goes into the computer

= we hit ‘save’ -> we name the file and store the information for later on when we save the file

= process of getting past information back -> we need to use the right ‘cues’ in order to get the information back, but if we do then we have the original information back!

READ BOX 6.3 – ON P 291-292

Automatic & effortful encoding

Encoding can be spilt further into categories.

read, define & provide and example of automatic encoding & effortful encoding

LEARNING ACTIVITY 6.2

Page 292 of your text, Questions 1,2 & 3

MODEL’S FOR EXPLAINING HUMAN MEMORY

As the human memory is complex and multifaceted, is it NOT studied together, rather it is broken down into pieces or sections, each being studied separately.

Each of these is referred to as a MODEL

The three main theories that explain how human memory functions are:1. Atkinson-Shiffrin multi-store model2. Baddeley and Hitch’s model of working

memory3. Craik and Lockhart’s levels of

processing framework

ATKINSON-SHIFFRIN’S MULTI-STORE MODEL OF MEMORY

Based in the 1960’s Proposed a shift in the single memory model =>

assumption that human memory has several systems/processes involved.

By Richard Atkinson & Richard Shiffrin – Americans. This model was also called/considered modal model,

as it merged and represented many other models during this time.

It is also known as the stage model, as it put forward that the flow of information moves in stages through each component of memory.

Information passes through 3 levels of memory as it is encoded, stored and retrieved, and these 3 levels are sensory register, short term store & long term store

Sensory register• The entry point for all new

information into memory from the external environment

• Stores vast amount of incoming visual information, for 100’s milliseconds

If information is attended to, it moves

into short term memory store Short term store

• A temporary working memory• Here we can manipulate information from every

day/common tasks• Holds all information that we are aware of at

that point in time• Has a limited capacity – 7 items at 1 time• Only held for about 30 sec unless we make an

effort to keep it there (attend to it), eg rehearsal

Rehearsal at time point critical

for more permanent storage (LTM)

Long term store• Information held relatively permanently in an highly organised way• Essentially can be an unlimited capacity• Unlike sensory register & short term store – information in long term store does not

usually decay and can stored for …… a whole lifetime• According to Atkinson & Shiffrin – it is our inability to retrieve required information

that results ineffective search strategies• Problems with retrieval may also be due to ‘interference’ with the information and

this results in a disruption in the retrieval process

If informatio

n is not attended to, it is

lost

Atkinson-Shiffrin multi-store model

Sensory Memory

Long-term

Memory

Short-term

Memory

Sensory info

Info not paid attention to…

Various reasons

Not rehearsed or

encoded

Lost from sensory memory

Displaced from short-term memory

Paid attention to info

Info encoded or rehearsed

Rehearsal

Retrieval

Forgotten

CRIMD

STRUCTURAL & CONTROLLED PROCESSES

Structural features of memory are the permanent features that do not alter from situation to situation – they are three levels of information processing: Sensory memory, Short term memory (STM) & Long term memory (LTM)

Control processes are the activities the individual does to process the information (eg they have ‘control’ over what they attended to and process) Attention – no information will be encoded if we don’t

pay attention to it Rehearsal – process that goes over information and

helps it be stored

But all of this was developed over 40 years ago ….. And we know have more knowledge …

EVALUATING ATKINSON & SHIFFRIN

Advantages Limitations

Identified characteristics of short term store as being different and apart from long term memory

Recognised the importance of short term store & its fundamental roles

Manitence and rehearsal are still relevant, although now more complex

Despite some newly learnt differences, still held as the original multi store model, although now just more complex

It is now clear that information does not ‘just flow’ as described in Atkinson & Shiffrin’ 3 stage sequence

There is a separate sensory register for auditory information & haptic (touch) information – and maybe even more now referred to as a sensory memory system

Short term store now believed to be a much more complex system

Different types of rehearsal have been identified in short term memory

Long term store is no longer a single store -> rather it includes more complex systems & structures of storage.


Page 295 of your text, Questions 1-7

Stages of memory – Sensory Memory Sensory Memory

Entry point of memory Capacity to store all sensory stimuli

(unlimited) Stored as the original form of stimulus

(buffer – need more processing before it can be stored)

Not consciously aware of most of the info in sensory stage, directing attention to it is what causes transfer to short-term memory

Incoming stimuli is stored as a memory trace in different sensory registers based on the type of sense Iconic memory – visual Echoic memory - auditory

Sensory Memory includes Iconic memory ( I as in eye)

Visual images are stored here for about 0.2-0.4 seconds

Stored as overlapping imagesAllows perception of flowing movement during a

film, or a figure drawn with a sparkler at night

Echoic memory (e as in ear)Sound stimuli are stored here for around 3-4

secondsThis is longer than in iconic memory as sound

takes longer to produceAllows comprehension of speech by connecting

individual sounds coherently into words and sentences


Page 299 of your text, Questions 1-7

NOTE: THERE IS ALSO AN INTERESTING READ IN BOX

6.4 ON PHOTOGRAPHIC MEMORY

Stages of memory – Short-term memory Activity: Capacity of STM

Read aloud the following series of numbers and ask students to recall each line in order. 6, 4, 7 (3 items) 9, 0, 1, 8 (4 items) 4, 3, 5, 7, 2 (5 items) 7, 1, 3, 8, 9, 4 (6 items) 3, 6, 8, 4, 9, 1, 5 (7 items) 2, 6, 4, 9, 1, 5, 7, 3 (8 items) 1, 7, 5, 8, 6, 3, 9, 2, 4 (9 items) 2, 6, 7, 3, 5, 4, 9, 1, 8, 3 (10 items)

On average, how many numbers did each person recall from each list? This is the capacity of STM.

Activity: Duration of STM Students learn the following sequence of numbers 4, 5, 3, 6, 2, 7, 8 Test immediately, then after 2 minutes How many people remembered the sequence? This is

duration of STM

Stages of memory: Short-term memory

Short-term memory (STM) is a memory system that has a limited capacity and duration

It also stores the information in an encoded format

Described as the “seat of conscious thought” – information only registers in STM once it is paid attention to – in conscious awareness

Duration of STMWithout rehearsal (active use), recall starts to

decline after about 12 seconds and is almost completely gone after 18 seconds (occasionally can last up to 30 sec)

Using rehearsal, information can be retained indefinitely in STM

LEARNING ACTIVITY 6. 7

Page 307 of your text, Questions 1-7, don’t worry about Q 8.

Capacity of STM The amount of pieces of information that can be

stored in STM is 7 ± 2 (between 5-9 items) Adding in more items displaces (pushes out)

existing items in STM – this is called displacement, shown below

Recalling information from long-term memory can also displace items from STM

Information is lost primarily within STM by either displacement (pushing out) or by decay (not being used- think fruit!)

Short-term memory

Now becomes ..

SHORT TERM MEMORY

Capacity of STM cont…..

Chunking is a method of increasing the capacity of STM Definiton: grouping or separate bits of information

into a larger single chunk of information. Separate pieces of info are remembered as single

units (groups info into chunks) Only similar info can be chunked together

(chunking) Still only retain 7 ± 2 chunks Chunks can be numbers, images, words, sentences,

phrases and even abbreviations This is why we have phone numbers broken into

parts …… 5427 2600 rather than 54272600.

SHORT TERM MEMORY

STM as working memory Term working memory is used to emphasise the active

part of memory where information we are aware of constantly, is actively ‘worked on; in a variety of ways

Enables us to use the information in sensory memory and move it to LTM

Often we combine information from sensory memory and LTM to perform mental processes, such as emotions, comprehension, problem solving, planning & daydreaming.

So this ‘working memory’ provides a temporary storage facility and mental workspace for information currently being used within a conscious cognitive activity.

The STM working memory is often compared to a computer

Effects of rehearsal

Rehearsal is the process of actively and consciously manipulating information to keep it in STM for longer than the normal 18 sec. (Increases duration)

Maintenance rehearsal Repeating info over and over usually vocally (out loud)

or sub-vocally (in your head) Works indefinitely to keep info in STM Does not always transfer info into long-term memory

Elaborate rehearsal Links new info to existing knowledge in a meaningful

way More active than maintenance rehearsal (requires

more effort) Very effective in transferring info into long-term

memory, especially when using personal link (self-reference effect)

EFFECTS OF REHEARSAL

Sensory Memory

Long-term

Memory

Short-term

Memory

Info not paid attention to…

Various reasons

Not rehearsed or

encoded

Lost from sensory memory

Displaced from short-term memory

Paid attention to info

Elaborative Rehearsal

Maintenance

Rehearsal

Retrieval

Forgotten

CRIMD

Sensory info


Page 312 – we can do this one as a class!

Stages of memory – Long-term memory

Long-term memory (LTM) is the relatively permanent memory system that has potentially unlimited capacity and duration (life-long) Info in LTM is inactive (not in use) and we are not

consciously aware of it until it is retrieved Due to the sheer volume of info in LTM, we use cues

(intentional or unintentional) to speed up the process of retrieval

Cues enable retrieval of specific info, not the entire contents of LTM – usually very efficient and very fast

Once retrieved, the info is stored in STM until it is no longer needed/in use. It is then transferred back into LTM

Failure to retrieve info from LTM is usually due to poor organisation during encoding and storage, or an inappropriate cue was used during retrieval

Info is encoded in terms of its meaning (semantically)

Types of long-term memory Memories in LTM are relatively permanent or at

least very longlasting Forgetting is most likely due to a failure to retrieve

info – poor encoding or poor cue Retrieval cues: a stimulus that assists in the

process of locating and retrieving information stored in memory.

There are two major types of LTM (LTM stores):① Procedural memory (Implicit memories –

“how?”)Knowing how to do stuff – actions and activitiesOften difficult to explain this knowledgeUsually learnt through observation and practiceNot usually consciously recalledE.g. making a cup of tea/riding a bike

Types of long-term memory

② Declarative memory (Explicit memories – “What?”)

Memories of facts and/or eventsUsually consciously recalledTwo types of declarative memory:a) Episodic memory

Memories of specific events or personal experiences Include references to “when” and “where”

b) Semantic memory Memories of general academic knowledge Facts not necessarily related to a specific place or

time Include references about “what” and “who”

Characteristics of the stages of memory

Stage of

memory

FunctionForm of storage

Capacity

Duration

Sensory memory (SM)

•Receives sensory information (stimuli) from environment

Original sensory formE.g. lingering sense of sound or pressure

Unlimited

•Varies based on sensation•Usually between 0.2 – 4 sec•Occasionally up to 10 sec

Short-term memory (STM)

•Receives info from SM•Receives info from LTM

Encoded in terms of physical properties of stimuliE.g. Starts with L

7 ±2 pieces or chunks of info

•Usually 18-20 sec•Occasionally up to 30 sec

Long-term memory (LTM)

•Storehouse for encoded info coming from STM

Encoded in terms of semantics - meaning

Unlimited

•Potentially permanent

Levels of processing framework – CRAIK AND LOCKHART

Craik and Lockhart proposed a framework of memory that emphasised the importance of the level of processing in how well information is stored in LTM

Info is stored best in LTM semantically (by meaning) so if the meanings of concepts are processes during learning, they are more likely to be recalled later – elaborate rehearsal is more effective for LTM than maintenance rehearsal

The deeper the level of processing (more elaborate encoding) the better the recall Visual encoding – “is there a letter k in the word?” Acoustic encoding – “does it rhyme with hat?” Semantic encoding – “is it a synonym of difficult?”

Levels of processing framework

Shallow processing

Visual encoding

What the word looks like

Colours, shapes and patterns detected

Intermediate processing

Acoustic encoding

What the word sounds like

Item is identified

Deep processing

Semantic encoding

What the word means

Meaningful associations are made

Levels of processing or depth are hard to define specifically and to measure

Despite this problem the idea of better processing and therefore better storage is supported widely by research

Craik and Lockhart

Model of working memory – BADDELEY AND HITCH’S

Baddeley and Hitch’s model of working memory describes STM as a functional system with three components that work independently but can also interact:

① Phonological loop (Verbal working memory) Verbal information is stored in a sound-based form

(phonological) Only hold about 2 sec worth of info (around 7 items

depending on length of words)

② Visuo-spatial sketchpad (Visual working memory)

Visual info is anything you can see or imagine, spatial info is position and location of objects in space

Also has limited duration and capacity (around 4 items)

Model of working memory – BADDELEY AND HITCH’S

③ Central executive Controls attention Integrates information from the phonological loop and

visuo-spatial sketchpad with info from LTM Coordinates the flow of info between the working memory

system and LTM Manipulates the info held in the phonological loops and

visuo-spatial sketchpad – the working component of the model of working memory

Episodic buffer (a fourth component added in 2000) A sub-system of the working memory that enables the

different components to interact with LTM Has limited capacity (about 4 chunks of info) Can hold info in any form and so can integrate

phonological loop and visuo-spatial sketchpad – temporary workspace where various pieces of info can be put together in a meaningful way

Controlled by central executive

Model of working memory

Sensory input

Phonological loop

Visuo-spatial sketchpad

Central Executive

Episodic Buffer

Long-Term Memory

Rehearsal

Rehearsal

ALAN BADDELEY AND GRAHAM HITCH’S MODEL OF WORKING MEMORY

Visio spatial SketchpadStorage of visual

and spatial information

Phonological Loop

storage of verbal speech informationEpisodic Buffer

Integrates useful LTM into what currently being worked on

Pulls together streams of different info into ‘episodes’

as a meaningful whole

The workbench

Central Executive

• Controls attention

• Integrates info from the two storage sub systems

• does the ‘working out’

•The seat of consciousness

BADDELEY & HITCH’S MODEL OF WORKING MEMORY

Read example on pg. 319

Once we have read it .....Going to party the following is:

- phonological loop stores the directions- Visio spatial sketchpad visualises the route- Central executive directs the Episodic

buffer to combine information from storage branches

- Episodic buffer also adds information from LTM

- Episodic buffer used as the mental ‘workbench’ to make adjustments

LEARNING ACTIVITY 6. 11&


Page 314 questions 1-6

&

page 320 questions 1, 4, 5, 7 ONLY

Again … just in cases you need to refresh

Stages of memory – LONG-TERM memory Long-term memory (LTM) is the relatively

permanent memory system that has potentially unlimited capacity and duration (life-long) Info in LTM is inactive (not in use) and we are not

consciously aware of it until it is retrieved Due to the sheer volume of info in LTM, we use cues

(intentional or unintentional) to speed up the process of retrieval

Cues ( retrieval cues) enable retrieval of specific info, not the entire contents of LTM – usually very efficient and very fast

Once retrieved, the info is stored in STM until it is no longer needed/in use. It is then transferred back into LTM

Failure to retrieve info from LTM is usually due to poor Organisation during encoding and storage, or an inappropriate cue was used during retrieval

Info is encoded in terms of its meaning (semantically)

Types of long-term memory Memories in LTM are relatively permanent or

at least very longlasting Forgetting is most likely due to a failure to

retrieve info – poor encoding or poor cue There are two major types of LTM (LTM

stores):① Procedural memory (Implicit memories –

“how?”)Knowing how to do stuff – actions and activitiesOften difficult to explain this knowledgeUsually learnt through observation and practiceNot usually consciously recalledE.g. making a cup of tea/riding a bike

Types of long-term memory

② Declarative memory (Explicit memories – “What?”)

Memories of facts and/or eventsUsually consciously recalledTwo types of declarative memory:a) Episodic memory

Memories of specific events or personal experiences Include references to “when” and “where”

b) Semantic memory Memories of general academic knowledge Facts not necessarily related to a specific place or

time Include references about “what” and “who”

TULVING (1983)

Tulving argues that semantic & episodic memory systems often work together in forming new memories – it isn't always one or the other.

In such instances, the memory that ultimately forms may consist of an autobiographical episode and semantic information.

Types of long-term memory Complete the table in your

workbooksTypes of Long Term MemoriesProcedural Memories

Definition: Example:

Declarative Memories

Definition: Example:

Episodic Memory Semantic Memory

Example: Example:


Page 325 questions 1-5 &

Organisation of Information in LTM

Long term memory’s most distinctive feature is its organisation of information

The task of retrieving information from LTM differs from the process of retrieving information from STM.

In short term memory, the search and retrieve tasks involve scanning only 7 + 2 items to locate the relevant information.

This 7 + 2 system doesn’t work with LTM, as there is such vast information to store, so there is a need for organisation to assist the storage and retrieval process.

BOUSFIELD & BOWER & CLARK Research into LTM has been studied for over 65 years now.

Research suggests:

Bousfeild & Sedgewick, 1944 Information may be recalled in burst of information, pause

briefly ….. Then recall more information and so forth. This suggested the way people recalled items reflected the

way the items were organised in LTM

Bousfeild, 1953 Noticed that when asked to recall information, people would

recall the words in groups or clusters, without being aware

Hockenbury & Hockenbury, 2006 It is still believed today that there is some kind of logical

association in LTM

Bower & Clark, 1969 Found that words that were memorised in stories would

recall up to 90% of 12 words compared to only 15% of words remembered in any order

They concluded that the results from recall in LTM were improved using some organisation method.


Page 327 questions 1 – 10

These are great exam practice questions !

Semantic network theory Information is stored in LTM as series of

overlapping networks Each network is interconnected by meaningful links Each item of information or concept in the network

is called a node When a node in a network is activated (retrieved)

all other related nodes are made available (easier to retrieve) – spreading activation

Linking multiple concepts removes the need for multiple copies of the same information

The shorter or thicker the link between nodes, the stronger the association between them and the faster the retrieval

Think of the semantic network theory as towns as nodes and the highways & streets as links

SEMANTIC NETWORK THEORY IN PRACTICE

Semantic network theory – spreading activation (loftus &

collins)

Red

Fire Engine

Apple

Traffic lights

Blue

Green

Yellow

Fire

EmergencyPolic

e

Fireman

Trustworthy

Brave

Courage


Page 330 questions 1 – 2 ONLY

These are great exam practice questions !

Serial position effect The serial position effect describes the differences in ability

to recall items in a list depending on their position in that list For immediate recall, typically items at the end of the list

are best recalled, then items at the start of the list, with items in the middle of the list least likely to be recalled

Recency effect Superior recall of items at the end of the list (most

recently experienced)Still in STM so easy to retrieve

Primacy effectSuperior recall of items at the start of the listHad the most time to rehearse for probably retrieved from

LTM Items from the middle of the list are no longer in STM and

haven’t had a chance to make LTM, so least likely to be recalled

Most clearly shown when tested immediately after exposure to the list. After 30 seconds recency effect is less apparent

Glanzer & Cuntiz (1966) research concluded that the STM & LTM must work together within the serial position effect. This was due recall better at both the start and end of the list, but with a delay of 30 seconds, this is beyond the limits of STM, and items at the start of the list were more likely stored in LTM.

http://withfriendship.com/images/h/38230/the-serial-position-effect.gif

Serial Position Effect



Neuron bases of memory Memories are stored throughout the brain linked together

by memory traces or “circuits” – interconnected neurons

However, different parts of the brain are involved in memory formation and retrieval to different degrees, and in different types of memories

New memories (either short or long term) are NOT stored in individual synapses but in the pattern of thousands of new interrelated connections

Looking for memories in a single nerve cell or synapse is a dead end

We know that there is a molecular basis to memory formation, what we do not know is exactly how thousands of these new connections hold our memories.

KANDELS SEA SLUGS

Read pages 335 – 336

Kandel identified that there are physical changes to neurons during the formation of new memoriesWorked primarily with large sea slugs

(Aplysia californica)Has very simple Nervous System 20, 000 neuronsLargest observable neurons – can be seen

with the naked eye!

Stimulated the siphon (gill in the tail of slug that squirts water to move slug away from danger)

According to Kendal: STM – would withdraw gill more and more quickly Forgetting – an hour later the withdrawal was again slow,

progressively faster with continued stimulation Habituation – eventually the slug stopped responding to the

stimulation as it caused no damage, it had ‘learned’ that the shock was harmless

Retraction of the gills changes over time indicating memory, so Each day the slug would habituate more quickly than the day before

This suggest some kind of LTM lasting days or even weeks

By studying the neurons involved in this process he identified the changes that allowed the learning to take place

The neurons were physically changing!

These changes are called collectively Long Term Potentiation

LONG TERM POTENTIATION

Neural basis for memory formation Synapse strength can increase in 3 ways

- Release extra neurotransmitter- Increase number of receptor sites- Growth of new synapses

LONG TERM POTENIATION – EXPLICIT STM

New Receptor Formation

Stronger neural impulse in post synaptic neuron

So, we know all from sea slugs ……..

Changes to neurons during memory formation are collectively called Long-term potentiation and include: Increased volume of neurotransmitter (function) Increased connectivity to other neurons (structure)

Increased number of branches (dendritic spines) at the dendrite and/or axon terminal ends – reinforce existing connections

New synaptic junctions are formed between neurons – creating new memory traces /neural pathways

Short-term memory storage only tends to increase neurotransmitter production, while long-term storage produces functional and structural changes

As a memory is recalled, all the neurons in the memory trace are activated in sequence. The strength and number of connections between each neuron increases the ease and speed of recall



Hippocampus & Temporal lobe

The hippocampus is a curved structure found in each of the lower temporal lobes – one in each hemisphere (think horseshoes!)

Its about 3.5cm long and in humans have one in each of the lower region of the temporal lobe

Amygdala

Corpus callosumThalamus

THE MEDIAL TEMPORAL LOBE

THE HIPPOCAMPUS & MEDIAL TEMPORAL LOBE – DAMAGE AND

MEMORYHenry Molaison (H.M.) was a split brain patient who

also had his medial temporal lobe (inner surface area towards the temporal lobe that includes hippocampus & amygdala) removed to stop his extremely severe epilepsy

Medical success in preventing seizures, however it affected his memory

His personality and basic functioning remained unchanged, however he suffered major memory impairment, and left with permanent anterograde amnesia (Can’t form new LTM’s) Eg. While he could remember events from before his

surgery, he couldn’t remember anything that occurred after his surgery – couldn’t form new long-term memories

Other mental abilities and STM fine Eg. He could retain info in STM as long as he

maintained attention and actively rehearsed it, but could not transfer it into LTM

H.M’S HIPPOCAMPUS & MEDIAL TEMPORAL LOBE – DAMAGE & MEMORY

This established that the hippocampus and medial temporal lobe are involved or has a role in LTM formation,

It is NOT the storage site of long-term memories however

Evidence that LTM is most definitely a distinct sub system of memory (STM fine)

This demonstrated that the hippocampus & medial temporal lobe has an important role in the formation or encoding of new declarative explicit memories (semantic & episodic), but not in the formation & retrieval of implicit memories (procedural)

Consolidation Theory Information that is transferred from STM to LTM needs a

period of time to be properly and permanently encoded and stored – (‘consolidated’ or set - think concrete!)

The consolidation theory suggests that there are structural/physical changes to the neurons (long-term potentiation & axon growth) as new memories are formed.

These changes take time (consolidation phase) and the memory can be interfered with (changed) or erased (lost permanently) during this time.

The new memory is vulnerable for at least 30 minutes after being experienced.

The hippocampus and medial temporal lobe play an important role in consolidation

Reconsolidation is the process of returning information back to LTM after it has been retrieved and used – the memory may be altered in this time.

CONSOLIDATION – RATS IN A MAZE

HUDSPETH, MCCAUGHT & THOMPSON, 1964

The research The Results

Rats learned to run a maze to find a food reward

4 groupsA – ECT immediatelyB – ECT 20 seconds afterC – ECT 30 minutes afterD – ECT 60 minutes after

A – all rats forgot completely

B – partial recallC – partial recall

(better than B)D – total recall

Consolidation seems complete after about 1 hour

LINKING CONSOLIDATION THEORY & H.M It has been proposed that the hippocampus acts as a kind

of memory formation area where the brain temporarily holds & processes the components of the info to be remembered e.g. sounds, location, images etc.

All of these components of the information need to be integrated or linked together, in the hippocampus to form a single episodic memory.

After looking at the consolidation theory – the example of H.M.’s lack of new long term episodic or semantic memory formation suggests that the process of consideration was unable to occur because of the lack of coordination between the structures needed to make new memories.

OR

THINK …..THE HIPPO ON CAMPUS LIVES ON MEMORY LANE

DEEP WITHIN THE TEMPORAL LOBE- THE AMYGDALA Mediation of fear – sympathetic

arousal Seizures involving the amygdala

involve intense fear Damage leaves a person unable

to learn a fear response through classical conditioning

Involved in remembering the emotional significance of an event

Can effect the consolidation of memory – stimulation better recall, retardation poorer recall

Also concerned with learning.

READ BOX 6.10 ON P 341 BRAIN TRAUMA &

MEMORY LOSS – BOXING



Amnesia Amnesia refers to any form of memory loss

Can be partial or complete Can be temporary or permanent

Amnesia is usually caused by brain trauma (inflicted brain injury or acquired brain injury)

The severity of the injury determines the type and severity of the amnesia Usually experience a period of unconsciousness,

followed by a period of confusion, then the period of time ‘forgotten’ usually shrinks to only a few seconds of minutes directly after the moment of trauma

Experience of amnesia can vary from a few days to several weeks, but commonly disappears suddenly, often after a natural sleep.

Types of Amnesia① Anterograde amnesia

Loss of memory of experiences that occur after the brain trauma

Difficulty learning new information Can clearly recall events before the trauma Can retain new info in STM indefinitely as long as it

is rehearsed Problem lies in the transference of information from

STM into LTM Experienced by people with Korsakoff’s syndrome

and Alzheimer's disease Korsakaff’s syndrome (neurodegenerative disease) Acute inflammation and damage to hippocampus and

thalamus Often associated with chronic alcoholism and thiamine

deficiency

Types of Amnesia① R

② Retrograde amnesiaLoss of memory of old info and experiences

before the trauma occurredLoss can extend back from moments to yearsUsually temporaryHowever, very common to permanently ‘lose’

the memory of the moment leading up to the trauma itself

This permanent loss is explained by the interruption of consolidation into LTM


P 347 QUESTIONS 1-6

THEN …

MOVIE ANALYSIS:MEMENTO/50 FIRST

DATES VS. THE BOURNE IDENTITY

Comment on how accurately the movie portrays the amnesia, include a psychological description

and explanation of the amnesia and the accuracy of these symptoms as depicted in the movie.

1 paragraph ONLY.

Dementia & Alzheimer’s Disease Dementia & Alzheimer's discussed in this

study design (for a full list FYI you can read box 6.12 for common types of dementia)

Common acquired brain injury is caused by neurodegenerative disease where brain tissue slowly deteriorates over time

DementiaProgressive decline in mental functioningLoss of mental capacity: decline in

intellectual ability, poor judgment, poor social skills and abnormal emotional

reactionsMemory loss is persistent and progressiveNot a normal part of ageingComes in many different forms

Alz

heim

er’s

Dis

ease

Alzheimer’s disease A form of dementia Physical break down of neurons causes plaques in the

brain – sections of neurons tightly bound together, causing gaps in other areas (only observable post-mortem) caused by high concentration of the protein amyloid in the brain (see next slide for Amy Loid!)

Often have low concentrations of neurotransmitter; acetylcholine

Affects around 100 000 people in Australia No accurate diagnostic tests available. Only accurately

diagnosed after death and brain tissue is examined for plaques

Memory loss, confusion, irritability and impaired decision-making are common symptoms

Memory loss is persistent and progressive Episodic memories are affected Forget words and names of people and commonly known facts Lose ability to follow directions of a story plot Lose ability to perform everyday skills

No cure, but can treat early stages with acetylcholine.

ALZHEIMER’S DISEASE: POST-MORTEM

So we know: Show high levels of the protein Amyloid Not usually in the brain Highly toxic – causes cell death Causes the development of the plaques

and tangles Brains also have a massive lack of

acetylcholine (an important neurotransmitter)

The rhyme:



Memory decline over the lifespan Memory decline is not an inevitable

consequence of ageing If it does decline, short-term memory and

explicit declarative memories (episodic and semantic) tend to be affected, rather than procedural memories

Aging and STM decline Info transmission in NS is generally less efficient

in older people (physical effects of ageing)The more complicated the task, the more STM

decline is evident in older peopleLess activity in areas of the frontal lobe

associated with STM when >60 years old

Memory decline over the lifespan Ageing and LTM decline

Episodic memories have been shown to start a steady decline as early as 30 years old

Procedural memories appear to remain intact over time

Semantic memories don’t appear to be affected much by age

However, older people don’t tend to encode new information in as much detail or as accurately as younger people – so often takes an older person longer to learn new things

Speed and fluency of retrieval also tends to decline with age

Decline in memory in older people is often explained by lack of motivation or more commonly, a lack of confidence

Recall of items is lower, but recognition of items is no different than younger people – use recognition tests, not recall

Memory decline can also be explain by cognitive slowing due to natural shrinkage of frontal lobes with age. Cognitive slowing affects all cognitive processes, not just memory

SO TO RECAP ….. Older people Do take longer to

learn new info

STM – depends on the task, easy one part tasks ok, tasks that require divided attention not so good. Recall down, Recognition same.

LTM - Episodic down, Procedural same, Semantic Same.



Chapter 6 Revision

True/False Quiz on page 355

Practice Test on page 356-360

Documents

Chapter 6: Memory. This knowledge includes: Comparison of models for explaining human memory: Atkinson-Shiffrin’s multi-store model of memory including