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Unit 3: Area of Study 2
Chapter 6 – Memory Theory notes
Without memory, every moment would be a new experience. Could you speak, dress
yourself, be in a relationship with anyone? Would you even know yourself? What
would happen every time you saw yourself in the mirror?
Memory isn’t a single thing. It’s a collection of complex interconnected systems. We do
not have a memory, we have different memory systems.
Memory is viewed as an active information processing system like a computer, which
receives, organises, stores and recovers information.
ENCODING
The acquisition (registering) and transforming raw information into meaningful stored form.
This involves forming a memory code. It requires attention which is an active process. Put
simply, encoding is the process of converting info into a useable form/code that can be stored
in memory.
STORAGE
This involves maintaining encoded information in memory over time. There is maintenance
and processing of encoded information. The depth of processing affects later
___________________. This is like a computer hard drive.
Memory storage is divided into three different kinds – sensory, short term and long term.
RETRIEVAL
This involves locating/recovering information from memory stores. Accessing the stored
information when needed involves searching memory and using retrieval strategies to get
encoded information out.
Three models for explaining human memory
1. Atkinson & Shriffrin multi-store model
2. Craik & Lockhart’s levels of processing framework
3. Baddeley & Hitch’s model of working memory
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1. Atkinson & Shriffrin multi-store model
Atkinson & Shiffrin proposed a model for memory consisting of three kinds/stages through
which information passes in a sequential way. Sensory  STM  LTM. They are seen as
separate sub-systems but they operate simultaneously and interact with other.
Information from environment  sensory memory  STM  LTM.
Each of the 3 stages differ in their function, capacity and duration.
Discuss Fig 6.5
SENSORY MEMORY
Sensory memory preserves information in its original sensory form for a brief time. Each
sensory impression is stored long enough to overlap with the next so that we experience the
world as continuous, not as a series of disconnected visual images or sounds. Any stimulus
that is registered is available to be selected for attention and processing (short-term or longterm memory). Information not attended to is quickly lost.
There are two sensory registers for visual and auditory information in sensory memory:
 ICONIC MEMORY (icon – image)
Visual sensory memory lasts about _________ seconds, called an icon. It registers the
sensory inputs long enough to be processed.
Test: Close your eyes for 1 min. Hold up your hand approx 25cm from your face. Open/Shut
eyes once quickly. Image of hand lasts for approx 1 second.
Example: movies are a series of individual frames. Our visual system & iconic memory
holds each frame long enough till the next frame comes. Our brain makes logical sense of it
all rather than seeing a series of still frames we see a “moving image”.
Other examples:
KINEOGRAPH or the flip book is one of the most
primitive forms of a physical contraption created to
produce an illusion of a moving picture. The flip book is a
book of several pages in which each succeeding page
contains the same image but slightly varied from the
previous image. When the pages are turned at a rapid
pace, the gradual variance of the images produce a
unified image that appears to be in motion.
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The THAUMATROPE is one of the next influential pieces created
advancing the portrayal of movement. The thaumatrope was a toy
that had a card with an image on either side of it. On the left and
right sides of the card were two strings that when twirled would
rotate the image at a fast enough pace to appear to combine the
two images into one. At the same time the thaumatrope was
explored, Peter Roget released an Article describing THE
PERSISTENCE OF VISION which many of these toys relied on in
order for the production of the illusion of a moving scene. The
thaumatrope also gave way to the exploration of ICONIC
MEMORY the short term, visual memory.
Experiments by Sperling (1960): Use of partial report technique to measure how rapid the
decay of the image was. Pg 298. He used a tachistoscope to quickly flash up some letters
onto a screen. Subjects had to recall as many as possible. Sujects could never recall all 12
letters as the visual image had “faded” before they had had time to write down all the letters.
He then introduced tones to direct the subjects to just one line of letters. Recall was now
perfect. He delayed the tone to test how quickly the images faded in iconic memory. Typical
duration of iconic memory is 0.2 – 0.4 seconds.
 ECHOIC MEMORY (echo – sound)
It is the memory of the auditory sensory system. Sounds linger like an echo!
Auditory sensory memory lasts ____________ called an echo.
Memory of sound lingers longer than sight. (Have you asked someone to repeat what they
said, but then remember?) Sounds are held for a few seconds in echoic memory then ->
STM to be processed. This is necessary for the comprehension of many sounds, especially
speech (need to identify all sounds in a word). We hear individual sounds. We can’t make
meaning of the words until you have heard all the sounds that make up a word. This is
sequential (not all at the same time). Auditory information must be stored long enough for all
the sounds to be received.
Experiment in text (bottom pg 301): Subjects asked to focus their attention on reading a
story and ignore any spoken words they hear. Periodically numbers are spoken. When a
signal sounds, subjects are asked to repeat the number just heard. Subjects reported being
unaware of the words tills the signal sounded and then they “heard” the words still in
memory.
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TRANSFER FROM SENSORY MEMORY => SHORT TERM MEMORY
o Not everything is ___________________
o What is attended to is transferred. Attention is required for transfer to short term
memory to occur. (Interesting, bizarre or different stimuli attract attention)
(Remember the “Cocktail party effect” - when we hear our name in a crowded room).
Our visual and sensory receptors are bombarded with billions of sights and sounds. Iconic
and Echoic memories select what we will attend to and transfer it to STM.
SHORT TERM MEMORY – (STM)
STM is a memory system with a limited storage capacity in which information is stored for a
relatively short period of time (unless rehearsed in some way)
Two routes by which information enters short-term memory:
- from the attended material in _____________________ memory
- retrieved from _____________________ memory.
Duration of STM
STM is a limited-capacity store that can maintain unrehearsed information for about 20 to 30
seconds.
- no longer an exact sensory image but an encoding of one.
- Information renewed by rehearsal or repetition (therefore can be kept longer than
about 20 seconds).
Capacity of STM – Miller (1956) 7  2
At any one time you can only recall about seven items from STM. If there are more items
added these “bump out” earlier items. If items are retrieved from LTM into STM, these will
______________some items from STM.
7±2 is the maximum number of pieces or units of information that short-term memory is
capable of holding.
Thus three things can happen to information in STM
1. Information can be________________
-through decay (not being used) eg forget what you wanted to say while
waiting for the other person to stop speaking.
-through displacement (being pushed out) eg forgetting a phone number while
saying goodbye to the operator
2. Retained through rehearsal
3. Information can be encoded and transferred to _________________________.
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STM as a working memory
STM is also called working memory. Information moves from sensory memory to STM to
LTM, and from LTM to STM. It is used to temporarily hold and manipulate (work on the)
information. It holds all of the information that is being consciously thought about at any
moment of time.
It involves interpreting and analysing information. It serves as a _______________ storage
of information in order to perform a task such as making decision, solving problems, and
comprehending written and spoken language.
For example: when performing a maths calculation. Numbers are temporarily held in
working memory (STM) while they are being manipulated/worked on.
For example: we can read because working memory holds the first few sentences in storage
while we process the rest of the sentences. Information is only held in STM while we are
consciously processing it. Then it either -> LTM or is discarded.
Some information is __________________ processed. It is encoded with little effort and
transferred to LTM.
For most information in STM, effort is required to process it, for example: a phone number
will be retained while dialing, but if distracted it will be forgotten. To remember information, it
is kept active so it remains for longer in STM and is transferred into LTM.
Allan Baddely (1999) described working memory as a system for processing, or working
with, current information across a wide range of tasks. It provides a ______________
storage facility and mental ‘workspace’ for information currently being used in some
conscious, cognitive activity.
Working Memory compared to a Computer (pg 307)
Keyboard
Sensory memory
CPU (Central
Processing Unit)
Sent to
Hard Drive
STM/working memory
Retrieved from
Hard drive
Hard Drive or
USB stick
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LTM
Chunking information
The capacity of STM may be increased by “chunking”. Chunking is the grouping of bits of
information into larger units that can be remembered as single __________.
Eg DNVRCEWVDCSV
VCR NSW VCE DVD
12 units to remember (>72)
4 units to remember (<72)
Chunk – A chunk is a group of familiar stimuli stored as a single unit, thus increasing the
amount of information in each chunk. Examples – numbers, images, words, sentences,
phrases, acronyms (eg VCE, CSIRO), chunks of numbers (eg telephone numbers, bank
account numbers, car registration, etc). Each unit fits one slot in STM
Effects of Rehearsal
Rehearsal is the process of repetitively verbalising or thinking about the information. STM
has a limited capacity and duration. Information is lost rapidly unless rehearsed. There are
two main types:
 Maintenance rehearsal
It is the process of simple, rote repetition of information to retain the information in STM.
Rehearsal of information is maintained acoustically (the sounds of the items are repeated
and stored). This can be covert (“in your head”) or overt (“out loud”). It can be visual or
spatial, but this is slower method.
It is very effective for retaining information in STM (can remain there indefinitely), but not
very effective in transferring it to LTM. Thus it does not always lead to long-term retention.
Recall that STM has limited capacity. If you are continually rehearsing something, the
amount of new information that can enter STM is restricted.
 Elaborative rehearsal
This involves _________________processing that focuses on the meaning of new
information, that is semantic encoding. It is the process of linking new information in a
meaningful way with information already stored in memory or with other new information at
the time of encoding. This aids in its storage and retrieval from LTM.
Information is more likely to be _________________ into long term memory through
elaborative rehearsal than through maintenance rehearsal. Think back to Psych Units 1 & 2.
What information do you remember well? Maybe doing an IQ test as you could personally
relate to it. LTM is far more effective at storing meaningful information than isolated
meaningless information. The self-reference effect is when we relate the information to
something personal to us.
Discuss Figure 6.22 pg 311
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Completing Learning Activities are useful because they make meaning of the information
we have just read and commit it to LTM for later recall.
2. Craik & Lockhart’s levels of processing framework
Craik and Lockhart (1972) are critical of the multi-store model. They suggest that memory is
not made up of three separate stores and that there is no clear distinction between STM and
LTM. Their levels of processing model focuses on the processes – different levels of
operations – involved in memory rather than on the structures involved.
The levels of processing model
Craik and Lockhart suggest that the
memory system consists of sensory
memory and one other memory
store, and that storage varies along
a continuum of levels of processing
ranging from shallow to deep
processing. How long and how well
information is stored does not
depend on three distinctly different
types of memory systems; it
depends on the level of processing
used during encoding.
According to Craik and Lockhart, the
type of rehearsal involved is crucial
to the depth of processing achieved.
Maintenance rehearsal uses shallow
processing to preserve information
but it doesn’t produce a lasting
memory trace. Elaborative rehearsal
uses semantic processing, therefore
it increases the depth of analysis and
produces longer lasting traces.
3. Baddeley & Hitch’s model of working memory
There are many entrance paths to working memory. It may hold the last few things noticed
in the environment, information from long-term memory or current thinking processes. It
can also be filled by recycling items currently in memory (memory rehearsal).
In Baddeley & Hitch’s (1974) working memory system, there are three main sub-systems:
1 Verbal working memory – phonological loop
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2
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Visual working memory – visuo-spatial sketchpad
Central __________________
1. The phonological loop (verbal working memory) stores and rehearses speech
information. It stores a _____________ number of sounds (phonemes) such as words, for a
short period of time. (Longer words with more sounds can take the same space as more
short words with fewer sounds). The phonological loop has a role in learning to read,
speech production, comprehension and acquiring a vocabulary.
The phonological loop has two subsystems – one for storage and one for processing. The
phonological store (the ‘inner ear’) holds the representations of sounds for approximately
1.5 – 2 seconds. These representations then fade unless they are taken up by the articulatory
control system (the ‘inner voice’). This system holds the sounds we want to keep or are
preparing to speak, in their order, for up to two seconds, by subvocalising (rehearsing by
silently repeating) them on a loop to prevent decay. When we silently read, the articulatory
control system converts written material to sounds (speech-based) so they can enter the
phonological loop.
2. The visuo-spatial sketchpad (visual working memory) temporarily stores and
manipulates visual and spatial information and is limited to about four items. It receives
information from visual perception or through generation of an _______________ from
visual memory. If you closed your eyes and tried to visualise the objects presently in the
room, you would be relying on the visuospatial sketchpad’s storage component.
For example this component is at work when someone is mentally trying to fit all the
components of a flow chart onto a single page. It is used in geographical orientation and
when planning spatial tasks.
For example remembering where a heat proof mat is placed when bringing out a dish from
the oven.
3. The central executive integrates information from the verbal and visual storage systems,
as well as information from long-term memory. It is the main coordinating system and it
controls the operations of working memory. It is needed for all aspects of cognitive
processing (thinking tasks), and enables processes such as problem solving, computation,
comprehension and search and comparison to be carried out.
For example, it is involved in the calculation of mental arithmetic tasks, making a decision,
analysing art, planning _______________ and coordinating behaviour. It is also responsible
for suppressing ___________________ information from conscious thinking. It helps you
decide what to do next and what not to do. Also responsible for shifts of attention. When
doing two things at once, the central executive allocates resources for each task and
decides when attention will be paid to each. It can’t do two things at once.
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This system does not explain how working memory is linked to LTM. Consequently,
Baddeley introduced a 4th sub-system in 2000 called the episodic buffer.
4. The episodic buffer briefly stores a limited amount of information from the phonological
loop and the visuospatial sketchpad with information retrieved from LTM, and integrates it into
a single multi-dimensional representation or ‘episode’. In doing so, it acts as an intermediary,
or ‘buffer’, between the phonological loop, visuospatial sketchpad and LTM so that we can
make sense of information entering different parts of working memory.
Baddeley & Hitch’s (2000) working memory model
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LONG TERM MEMORY – (LTM)
Consider how much information is stored in your LTM from birth, and in mine and in
someone who is 80 yrs old. Consider how long it takes to find information. Eg where you
lived when you were 6. We are amazing creations! When you retrieve that information,
Long-term memory (LTM) is the relatively _________________ store that can hold vast
amounts of information for long periods of time.
STM
Capacity
Duration
Encoding
Forgetting
Entry
7± 2
20 – 30 seconds
(unrehearsed)
Mainly acoustically (what
we saw, did, heard etc)
Displacement/decay
Through attention or
retrieval from LTM
LTM
Unlimited
Relatively permanent
Mainly semantically (in
terms of meaning)
Interference/decay
Through elaboration
(from STM)
 It is an unlimited capacity store that can hold information over lengthy periods of time.
 It can store for indefinite periods of time, even across a whole lifetime. Some
psychologists believe that information stored is permanent.
 If storage is permanent then it is believed that forgetting occurs in LTM not because
the memory is gone but it is unable to be retrieved for some reason (possibily
because of poor organisation).
 Information is transferred from short term memory. Information being maintained in
short-term memory through rehearsal is gradually absorbed into long-term memory.
 The information stored is primarily _________________stored, that is in terms of its
meaning.
ORGANISATION OF INFORMATION IN LONG-TERM MEMORY
Theorists suggest that people have separate memory systems for different kinds of
information. Information is retrieved from LTM using cues (prompts).
The most basic division of memory into distinct systems contrasts procedural
memory with declarative memory.
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LTM
Procedural - Implicit
Declarative - Explicit
(know how – no conscious recall)
(know that – conscious recall)
Semantic
(meaning)
Episodic
(experiences)
 PROCEDURAL MEMORY SYSTEM
The procedural memory houses memory for actions, skills and procedures that have been
learned ________________. It is the memory of ‘how to do something’. It contains
memories of how to execute such actions as riding a bike, typing and tying one’s shoes.
 Procedural memory forms after practice or conditioning (difficult to put into words).
 The memory cannot always be consciously activated and communicated. For
example if doing a complex dance routine, if asked about the rapid series of motor
behaviours involved, would have difficulty in communicating that.
 Procedural memory is considered a relatively primitive type of memory.
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 DECLARATIVE MEMORY SYSTEM
The declarative memory system is the memory of specific facts or events which can be
brought to conscious memory (explicitly stated or declared) and usually communicated. It
handles _______________ information. It retains recollections of words, definitions,
names, dates, facts, events, concepts and ideas.
Example: describing a movie you saw or what happened at school today.
Subdivisions: Declarative memory is further subdivided into semantic and episodic memory.
Both contain factual information.
1. SEMANTIC MEMORY SYSTEM
The semantic memory system contains general knowledge that is not tied to the time
when the information was learned (it is held in storage). It is the organised knowledge
that we have about the _______________.
It includes our specialised knowledge in areas of expertise, academic knowledge, about
famous individuals, places, meaning of words, formulae, symbols, concepts etc. The
person doesn’t remember when they learned these facts. Information is stored
undated.
Example: the moves in a chess game or spelling rules “i before e”.
2. EPISODIC MEMORY SYSTEM
This is the declarative memory system that stores life _________________. It is made
up of chronological, or temporarily (related to time) dated, recollection of personal
experiences.
It is the record of things you’ve done, seen and heard, including WHERE and WHEN
you did these things, saw them or heard them. It remembers specific events and
personal experiences (like a neural diary).
NOTE:
Episodic memory is like an autobiography,
Semantic memory is like an encyclopedia
Semantic and episodic systems often work together in forming new memories. A
specific episode is recalled usually being related to some other general knowledge
based information. (For example if doing an assignment one evening, you remember
when and where you did it, as well as the information).
Amnesia provides evidence for the two memory systems.
Declarative memory can be severely impaired, while procedural memory is left largely
intact. Eg. With amnesia you can learn and remember new motor skills, but can’t remember
the name of the person teaching you.
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Organisation of information in LTM
Long term memory houses a vast amount of information and needs some organisation.
LTM is characterised by overlapping organisational _________________. There are
several different theories which describe and explain the way in which the vast amount of
information is stored and organised in long-term memory.
SEMANTIC NETWORK THEORY
Semantic network theory proposes that information in LTM is organised systematically in
the form of overlapping networks of concepts and units of information that are
interconnected and interrelated by meaningful ___________________.
Much knowledge seems to be organised into less systematic frameworks, called semantic
networks (Collins and Loftus, 1975). (Less systematic than a conceptual hierarchy because
not all information fits neatly into a conceptual hierarchy.)
A semantic network consists of nodes representing concepts, joined together by pathways
that link related concepts.
Nodes
Represent the __________________. Each node is linked with a number of other nodes. As
we retrieve information, the activator of one node causes other related nodes to be
activated.
Pathways
Lines connecting the nodes are pathways; pathways (can be labelled) show how the
concepts are related to one another. The length of each pathway represents the degree of
association between two concepts. Shorter pathways imply stronger associations and
therefore quicker retrieval times.
Example: Qantas Map
– cities are the nodes
– arrows between the cities are the flight pathways
Retrieval of information from LTM starts with searching a particular region of memory and
tracing associations for links in that region rather than randomly searching the whole LTM
(like using Google as a search engine)
Spreading activation
When people think of a word, their thoughts naturally go to related words. It is assumed
that activation spreads out along the pathways of the semantic network surrounding the
word.
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An example of the semantic network theory
SERIAL POSITION EFFECT
The serial position effect occurs when recall of items in serial lists tends to be
_____________ for items at the beginning and end of a list than for items in the middle of
the list (end best, then beginning, then middle).
Rundus (1971) performed an experiment where participants were required to recall a list of
20 words. The percentage of recall for each word is graphed as a function of its
position on the list. This graph results in a ‘U’ curve.
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The effect involves two components :
Primacy Effect
This occurs when items near the beginning of a list are recalled better. This reflects LTM
storage where the words at the beginning of the list get rehearsed more often than the
others so therefore are more likely to be transferred into LTM than later words.
Recency Effect
This occurs when items near the end of a list are recalled better. Recency effects reflects
STM storage since the words at the end of the list are most recently presented, they are still
available in STM if participant’s recall is tested_________________.
 During presentation, all items enter STM but as additional ones are added, some are
transferred into LTM and others are lost (because STM can only hold 72 items).
The words in the middle therefore are lost and hence the low recall (unless they are
unique in some way).
 If recall is delayed 30 seconds or more, no recency effect is shown, due to the words
being lost from STM.
Neural basis of Memory
 Role of the neuron in memory formation
How does our brain form memories? Researchers interested in memory formation and
storage focus on what occurs in the brain during memory formation. Specifically, they are
interested in changes within the brain’s neurons and at the synapse between neurons.
Research suggests that neuronal
activity is the basis of memory formation
and storage, and that each memory has
a unique pattern, or memory trace. A
memory trace is a physical or chemical
change that is believed to occur in brain
cells as they store information during
memory formation. One neuron
stimulates another neuron to fire by
releasing its neurotransmitters
(chemicals released at the synapse that
transmit messages between neurons)
into the synapse.
Studies of lower order animals indicate that when this stimulation occurs, a lasting change in
the efficiency of the synapse is produced (Kandel & Schwartz, 1982). The receiving neuron
becomes more likely to fire again in the future, thus making it easier for nervous impulses to
travel the same pathway again.
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In 2000, Columbia University’s Professor Eric Richard Kandel won the Nobel Prize for his
previous work on the physiological basis of memory formation in neurons. In order to discover
the molecular mechanisms involved,
Kandel had studied learnt reflexes in a
simple organism, the Aplysia – or sea
slug. Aplysia were chosen because
they have a very simple nervous
system with a small number of
extraordinarily large and distinctively
pigmented nerve cells. This made it
easy to observe any physiological
changes, particularly synaptic
changes, occurring during learning.
Kandel observed the Aplysia’s neural
connections before and after learning, noting any anatomical or chemical changes,
particularly those relating to changes in the level of neurotransmitters released at the
synapse.
Kandel taught the Aplysia to respond to touch and pain. He concluded that reflex learning had
occurred because the Aplysia had formed a memory of the association between touch and
pain, causing the Aplysia to release more of its neurotransmitters into its synapses.
Based on these findings, Kandel theorised that memory formation depends on neuronal
activity, specifically related to the release of neurotransmitters at specific synapses. Increases
in the level of neurotransmitters strengthen the synaptic connections between neurons,
resulting in more efficient synaptic transmission and more efficient neural circuits.

Role of the hippocampus and temporal lobe
Psychologists believe that no single brain structure or area is responsible for memory.
Research results, such as those provided by Karl Lashley (1950), suggest that memory is the
result of the interaction of a number of brain areas. Lashley concluded that a single memory
can be stored in various parts of the brain; therefore, memory depends on the integration of
activity in several areas of the brain. These areas include the temporal lobes and the
hippocampus.
The fact that individuals who experience
damage to their temporal lobes often
suffer from amnesia – a temporary or
permanent, partial or complete loss of
memory – suggests that the temporal
lobes play a major role in memory
formation and storage.
Research findings indicate that severe
damage to the left temporal lobe results in
difficulty remembering and understanding
language, causing an inability to name
familiar objects, places or faces.
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Research has also shown that damage to the right temporal lobe can result in impaired
memory for nonverbal information such as recognising familiar faces, music and pictures.
Located below the cortex and buried deep within the brain, the hippocampus extends into
the temporal lobes. Psychologists believe that the hippocampus is heavily involved in forming,
sorting and storing memories. The hippocampus is located close to Wernicke’s area. PET
scans show the hippocampus ‘lighting up’ when people recall words, suggesting that it plays a
major role in the memory of language. The fact that people who experience severe
hippocampal damage also experience memory loss for language also supports this view.
Organising spatial information and the ability to navigate through space is also believed to be
linked to hippocampal activity. Research suggests that if the hippocampus is damaged,
specific types of new information may not be able to enter the memory system and old
information in LTM may not be able to be accessed. Individuals with hippocampal damage
have difficulty forming new memories, particularly memories involving information or events
related to the self. These memory deficits have led to the belief that the hippocampus also
plays a crucial role in the transfer of information, acting as a sort of ‘switching station’ where
new information is passed from STM into LTM for lasting storage.
Case Study: H. M. (Henry Molaison)
The hippocampus’ role in memory is clearly illustrated by a famous case study
of a patient, known as ‘H. M.’, by Canadian psychologist Brenda Milner. Two
years after an operation to minimise epileptic seizures damaged his
hippocampus, 29-year-old H. M. continued to give his age as 27. He also
reported that it seemed as if the operation had just taken place. His memory of
events before the operation remained clear, but he found forming new LTMs
almost impossible. When his parents moved to a new house a few blocks away
on the same street, he could not remember the new address. Month after
month, he read the same magazines over and over without finding them
familiar. H. M. still had a short-term memory, but if you met him and then left
the room to return 15 minutes later, he would not recognise you. Yet, he vividly
remembered his early past, and he could retain small bits of new information
for short periods. At one point Milner asked H. M. to remember three numbers.
By making elaborate associations, he managed to retain the numbers for 15
minutes. But moments later, he could not recall the digits or the train of
associations that had helped in recalling them. He could not even remember
being assigned the task.
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Consolidation Theory
Consolidation is a process involving the gradual conversion of information in to durable
memory codes stored in long term memory. Put simply, it is the transfer of information from
STM -> LTM. It is the process whereby ________________ memories are formed.
The transfer of information from STM to LTM requires a period of time for consolidation or
stabilisation in order for it to be permanently stored.
For a memory trace to become permanent, some neurological changes take place and
these changes are time dependent. It is proposed that if the memory is disrupted in certain
ways during the consolidation phase, memory _____________ occurs.
Physical changes to the neurons in the brain occur when something new is being learned
and immediately following learning.
Consolidation appears to be a gradual process and the material remembered is vulnerable
to disruption for at least 30 MINUTES. It is like the information is wet cement. It takes time
to consolidate and move the information into LTM. Factors such as a blow to the head, brain
injury, ECT (electroconvulsive therapy) could disrupt the consolidation and lead to memory
loss for events immediately preceding the accidents.
For example if someone is knocked unconscious they are unable to report any memory of
events immediately preceding the accident. This is because the memories didn’t have a
chance to be consolidated and transferred to LTM.
Amnesia resulting from Brain Trauma and Neurodegenerative diseases
Brain Trauma is any damage/injury that causes a disruption to the brain’s normal functioning.
Like any brain injury, brain disease also disrupts brain functioning, including memory
processes. A range of neurodegenerative diseases can gradually and progressively kill nerve
cells, causing nervous system dysfunction and permanent loss of ability. Neurodegenerative
diseases can have a genetic cause but they can also be caused by chronic alcoholism,
tumour, stroke, toxins, chemicals and viruses.
Alzheimer’s disease is an age-related neurodegenerative disease linked to damaged
neurons, resulting in memory failure.
Amnesia is the partial or complete ___________ of memory. The memory loss can be
temporary or permanent. Amnesia can be STM, LTM, learning new information or no sense of
the present.
 Extensive memory loss due to injury to the head or brain surgery
or_______________.
 Causes include: stroke, falls, car accidents, diseases, anoxia (oxygen deficiency), brain
tumours, neurosurgery, Korsakoff’s syndrome (a disease produces permanent brain
damage resulting from malnutrition associated with chronic alcoholism), and severe
malnutrition.
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Two types of Amnesia:
1. Anterograde Amnesia (Antero - means forward in time or after the injury)
 A person loses memories for events that occur ______________ the injury
 The memory of events that occurred prior to the damage remains.
For example they will _____________ learn the names of new people they meet, even
though see them daily.
This is due to brain damage, of the limbic area including hippocampus, amygdala, and
thalamus.
Examples:
- Case Study of H.M. Recall that he underwent surgery for epileptic seizures
which wiped out his ability to form long term memories; only a functioning short
term memory was left. He had no recollection of any events after the operation
(was only aware of the recent 30 seconds of life). The operation involved the
removal of the hippocampus, a structure in the limbic system. LTM of memories
prior to the operation were intact, STM continued to function and by rehearsal
he could retain information in STM for longer, but he did not have the ability to
form long term memories (due to lack of the process of consolidation in the
limbic system).
- Korsakoff’s syndrome – acute brain inflammation and damage as a result of
chronic alcoholism.
- Alzheimers – degenerative brain disease with abnormal changes in brain tissue.
Alzheimers intro video (3 mins)
-
“50 first dates” movie with Adam Sandler & Drew Barrymore. Lucy suffers from
Goldfield Syndrome, a fictional form of anterograde amnesia in which each
day's events disappear from her memory overnight.
2. Retrograde Amnesia (retro means backwards in time – before the injury)
A person loses memories for events that occurred ___________ to brain damage. Loss can
include some or all of life memories. Memory loss like this may extend back a few moments,
days, weeks or years depending on the severity of the blow to the head. This may be
received in a car accident, sporting accident, boxing match etc.
ECT can also cause it (treatment for depression).
Retrograde amnesia is usually of a _________________ nature and is rare in occurrence.
It is usually restricted to events immediately preceding the _______________.
As time passes memory of events is restored, proceeding from the events ______________
in time to the most recent. However events prior to the injury may be lost permanently
because were never encoded due to the interruption in the consolidation process.
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Dementia and Alzheimer’s disease.
Dementia is an umbrella term used to describe a variety of symptoms of a large group of
illnesses or neurodegenerative diseases that cause a progressive decline in a person’s
mental functioning. Dementia usually develops over a number of years, gradually worsening.
It is not a normal part of the ageing process. Most people who age do not develop dementia.
Jessica’s Story - Childhood Dementia (6 mins)
More than 60 known diseases or illnesses,
many of which are neurodegenerative, can
cause dementia symptoms. When caused by
neurodegenerative factors, the symptoms are
usually irreversible. The most common form
of dementia is Alzheimer’s disease,
accounting for about 50% to 70% of all
dementia cases.
Alzheimer’s disease is a neurodegenerative
disease characterised by the gradual
widespread degeneration of brain neurons,
causing memory loss, a decline in cognitive
and social skills, and personality changes.
Currently Alzheimer’s disease is the fourth
largest cause of death in Australia.
Neuroimaging techniques such as PET and
MRI are frequently used to identify the extent
of brain damage resulting from Alzheimer’s
disease. The computer-generated images
produced by PET and MRI make it possible
to identify the parts of the brain that have
deteriorated.
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Memory Decline over the Lifespan
There may be some naturally occurring decline in memory as people age, but is it an
inevitable consequence of growing older?
Factors influencing memory decline:

If the information is well learned and _______________ often it will be retained.

The types of information (and related LTM stores). There is a steady decline in episodic
memory. Procedural and _______________ memories remain intact over time.

Depends on measure of retention used; recognition differs little in relation to age whereas
recall does decline. Ability to free recall lists declined gradually with age, but no difference
on cued _________________ tests.

A low level of motivation, or self-confidence of the individual will result in __________
being retained.

Information that was once a part of daily ____________ is retained.

There is age related decline in ability to retain newly learned material eg. recall of
nonsense syllables, wordlists, strings of numbers, written prose, the name of someone just
introduced. This could be due to:
- Slowing of neural processes can impair performance is tasks involving memory.
- Lack of ___________________ for memory of these types of tasks.
- Loss of confidence in their memory

The more complex, challenging and stimulating a person’s occupation or lifestyle, the
_________________ they maintain mental abilities including memory.

STM changes are very small with simple tasks but more significant when the tasks are
more ____________________.

Difficulties occur at the encoding and retrieval stage.

Time taken to encode information is __________________ in aged people and less
accurately.
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Memory Decline with Age Summary:


Some people have very good memories in their old age – their memories are not affected at all.
Others experience effects in working memory and declarative memory (episodic and semantic)
In Short Term Memory



Depends on the nature of the task –
Simple tasks are not generally affected
More complex tasks (eg those requiring divided attention like approaching a 4 way intersection,
with all the information to deal with – need to be processed in the working memory) may be
affected.
In Long Term Memory






Depends on the type of memory
Episodic appears to decline
Procedural appears to remain the same
Semantic appears to remain the same
Take longer to learn new information and skills – don’t encode new information with as much
detail or precisely.
Speed and fluency of retrieval decline
Some of the reasons could be
 Motivation lower
 Confidence lower
 Measure of retention impacts memory (recognition not affected, recall decreases)
 CNS slows (probably the main reason) – called “cognitive slowing” – frontal lobes decrease
in size.
SUMMARY OF MEMORY DECLINE RELATED TO AGE
Taken from old Nelson Psychology Units 3 & 4, Published by Thomson and Nelson, 2005, Authors too
numerous to mention!! :
“There may be a naturally occurring decline in memory for certain types of information as we age, but
fortunately this does not apply to all types of information. IN particular, and as mentioned earlier,
procedural memories (memories of how to do things) are very resistant to forgetting. If we have
carefully encoded and regularly use our semantic memories (memories of impersonal facts and rules
that help us to make meaning), these can also be quite resistant to forgetting.” (P 259)
“Research such as Nilsson’s indicates that although decline in episodic memory can begin as early as
30, procedural memories seem to remain intact over time. Semantic memories also appear to be very
resistant to the ageing process.” (P 260)
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