Download 6.+Memory

Chapter 6: Memory
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
 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
Note


 SACs
ERA
 Week 3 (approx.)
 /30 marks
 Test
 Week 8 (approx.)
 /20 marks

If 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



-
-
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
How is information processed?
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:

Processing different
information
storing information
(learned through experience)
Memory
systems
retrieving the information
(when needed)

Storing information
(in different ways & types of
information)
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!
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 is an active (uses energy) information-processing system that:
 Receives,
 Organises
 Stores &recovers information
Encoding
Incoming
sensory input
• Info is
converted
for storage
• Info is
retained in
brain
Storage
Retrieval
• Info is
recovered
when
needed

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.
 Encoding
= hitting the letters on the key board ->
it goes into the computer
 Storage
= we hit ‘save’ -> we name the file and
store the information for later on when
we save the file
 Retrieval
= 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!
Automatic & effortful encoding
Encoding can be spilt further into categories.
read, define & provide and example of automatic encoding &
effortful encoding
Page 292 of your text, Questions 1,2 &
3
 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 model
2. Baddeley and Hitch’s model of working memory
3. Craik and Lockhart’s levels of processing framework






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
•
If information is attended
to, it moves into short
term memory store
•
The entry point for all new
information into memory from
the external environment
Stores vast amount of incoming
visual information, for 100’s
milliseconds
Short term store
•
•
If
information
is not
attended
to, it is lost
•
•
•
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
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
Rehearsal
Paid attention
to info
Sensory
info
Sensory
Memory
Info encoded or
rehearsed
Short-term
Memory
Long-term
Memory
Retrieval
Info not paid
attention to…
Not rehearsed
or encoded
Lost from sensory
memory
Displaced from
short-term memory
Various reasons
Forgotten
CRIMD
 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 …
Advantages




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
Limitations

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

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
 Iconic
memory ( I as in eye)
Visual images are stored here for about 0.2-0.4 seconds
 Stored as overlapping images
 Allows 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 seconds
 This is longer than in iconic memory as sound takes
longer to produce
 Allows comprehension of speech by connecting
individual sounds coherently into words and sentences

Page 299 of your text, Questions 1-7
 Activity:

Read aloud the following series of numbers and ask students to
recall each line in order.









Capacity of STM
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


 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 STM


Without 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
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
Now becomes ..


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!)
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.
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
 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 subvocally (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)
Maintenance
Rehearsal
Elaborative
Paid attention
to info
Rehearsal
Sensory
info
Sensory
Memory
Short-term
Memory
Long-term
Memory
Retrieval
Info not paid
attention to…
Not rehearsed
or encoded
Lost from sensory
memory
Displaced from
short-term memory
Various reasons
Forgotten
CRIMD
Page 312 – we can do this one as a
class!
 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)
 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):
Procedural memory (Implicit memories – “how?”)
①





Knowing how to do stuff – actions and activities
Often difficult to explain this knowledge
Usually learnt through observation and practice
Not usually consciously recalled
E.g. making a cup of tea/riding a bike
Declarative memory (Explicit memories – “What?”)
②
Memories of facts and/or events
 Usually consciously recalled
 Two types of declarative memory:
a) Episodic memory



Memories of specific events or personal experiences
Include references to “when” and “where”
Semantic memory
b)



Memories of general academic knowledge
Facts not necessarily related to a specific place or time
Include references about “what” and “who”
Stage of
memory
Sensory
memory
(SM)
Function
•Receives sensory
Original sensory form
information (stimuli) E.g. lingering sense of
from environment
sound or pressure
Short-term •Receives info from
memory
SM
(STM)
•Receives info from
LTM
Long-term
memory
(LTM)
Form of storage
•Storehouse for
encoded info
coming from STM
Capacity
Duration
Unlimited
•Varies based
on sensation
•Usually
between 0.2 –
4 sec
•Occasionally
up to 10 sec
Encoded in terms of
physical properties of
stimuli
E.g. Starts with L
7 ±2 pieces •Usually 18-20
or chunks sec
of info
•Occasionally
up to 30 sec
Encoded in terms of
semantics - meaning
Unlimited
•Potentially
permanent
 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 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
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
 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)
Visuo-spatial sketchpad (Visual working memory)
②


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)
Central executive
③

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

Sensory input
Rehearsal
Rehearsal
Phonological
loop
Visuo-spatial
sketchpad
Central Executive
Episodic Buffer
Long-Term Memory
Phonological
Loop
Central Executive
• Controls attention
• Integrates info from the
two storage sub systems
• does the ‘working out’
storage of verbal
speech information
Episodic Buffer
Integrates useful LTM
into what currently
being worked on
Pulls together streams
of different info into
‘episodes’ as a
meaningful whole
•The seat of consciousness
Visio spatial
Sketchpad
Storage of visual and
spatial information
The workbench
 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
Page 314 questions 1-6
&
page 320 questions 1, 4, 5, 7 ONLY
 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)
 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 activities
Often difficult to explain this knowledge
Usually learnt through observation and practice
Not usually consciously recalled
E.g. making a cup of tea/riding a bike
Declarative memory (Explicit memories – “What?”)
②
Memories of facts and/or events
 Usually consciously recalled
 Two types of declarative memory:
a) Episodic memory



Memories of specific events or personal experiences
Include references to “when” and “where”
Semantic memory
b)



Memories of general academic knowledge
Facts not necessarily related to a specific place or time
Include references about “what” and “who”
 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.
 Complete
the table in your workbooks
Types of Long Term Memories
Procedural Memories
Definition:
Example:
Declarative Memories
Definition:
Episodic Memory
Example:
Example:
Semantic Memory
Example:
Page 325 questions 1-5 &
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.

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 !
 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
Fireman
Traffic lights
Fire Engine
Green
Fire
Trustworthy
Red
Emergency
Yellow
Blue
Police
Brave
Courage
Apple
Page 330 questions 1 – 2 ONLY
These are great exam practice
questions !


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 effect
 Superior recall of items at the start of the list
 Had 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

http://withfriendship.com/images/h/38230/the-serial-position-effect.gif

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.
Page 333 questions 1 – 3

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.
 Read
pages 335 – 336
 Kandel
identified that there are physical changes to
neurons during the formation of new memories




Worked primarily with large sea slugs (Aplysia
californica)
Has very simple Nervous System
20, 000 neurons
Largest 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

 Neural
basis for memory formation
 Synapse strength can increase in 3 ways
-
-
Release extra neurotransmitter
Increase number of receptor sites
Growth of new synapses
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
Page 337 questions 1 – 11
 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
Corpus
callosum
Thalamus
Amygdala



Henry 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
 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)
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.

The research
Rats learned to run a maze
to find a food reward
 4 groups
A – ECT immediately
B – ECT 20 seconds after
C – ECT 30 minutes after
D – ECT 60 minutes after

The Results
A – all rats forgot
completely
B – partial recall
C – partial recall (better
than B)
D – total recall

Consolidation seems
complete after about 1
hour

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.
 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.
Page 342 questions 1 – 6

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.
①






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
R
①
Retrograde amnesia
②





Loss of memory of old info and experiences before the trauma
occurred
Loss can extend back from moments to years
Usually temporary
However, 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
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 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
 Dementia





Progressive decline in mental functioning
Loss of mental capacity: decline in
intellectual ability, poor judgment, poor
social skills and abnormal emotional
reactions
Memory loss is persistent and progressive
Not a normal part of ageing
Comes in many different forms

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.
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:
Page 351 questions 1 – 3
 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 people
Less activity in areas of the frontal lobe associated with STM
when >60 years old

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
 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.
Page 351 questions 1 – 3

True/False Quiz on page 355

Practice Test on page 356-360