Download Memory Models


“Human Beings are Information
Processors”
› We take information into our brains, and
store it for later, thus creating a memory
› When we see/experience something, we
must encode it, in order for it to become a
memory
› How does this happen?
 There are three different theories
Idea that humans are information
processors
 Memory consists of a number of separate
“stores”
 Memory process is sequential

› Processes include:
 Attention, coding, and rehearsal
 You must pay attention to something to remember it
 You give that thing a “form” to remember it (encoding)
 You must then rehearse, or repeat the memory so that it
can be stored
Atkinson and Shiffrin 1968
 The basic structure of memory

Encoding
Sensory
Input

Sensory Memory
› Information comes into the mind through the
senses.
› Information will stay here for a few seconds

Short Term Memory
› It then goes into the Short Term Memory
› Stays for 6-12 seconds
› Can only hold 7 items at a time
› Quickly lost if not given attention

Long Term Memory
› Unlimited Capacity
› Memories are encoded, and placed into the
LTM
› Not exact memories, stored in outline form
› When we retrieve information, we may fill in
gaps to create a meaningful memory





Participants were presented with sets of triplets to
memorize (three letters) (IE: KDF, CLS)
After showing the participants the triplets, they were
asked to complete a counting task which lasted
either: 3,6,9,12,15, or 18 seconds. (Counting back
wards by 3’s)
As the amount of time spent on the counting task
increased, the ability to recall the triplets became
worse
At a 3-second interval, 80% of the triplets were
recalled, at the 18 second interval less than 10% were
recalled
This is because when rehearsal is prevented,
information is lost rapidly from the STM
Cat
 Car
 Face
 Tractor
 Shoe
 Clog
 Tiger
 Rain
 Tree

Fig
Apple
Grass
Grade
Tire
Leaf

Serial Position Curve
› Participants were presented with a list of 15
words and told to memorize them
 Half were asked to recall the words immediately
(IFR – immediate free recall)
 The other half were asked to recall after a delay of
30 seconds (during the delay they were asked to
count backwards in threes from a 3-digit number)
(DFR – delayed free recall)
› The researchers hypothesized that participants
would recall the first few and last few words, but
would forget the middle words
Primacy effects: The ability to recall the
first few words in a set because the new
stimulus received the most attention,
and had the most rehearsal, transferring
the words from the STM to the LTM
 Recency effects: The ability to recall the
last few words in a set because they
remain in the STS when recall
commenced

IFR group recalled words at the
beginning and the end of the list (Serial
Position)
 DFR group did not recall the words at the
end because the 30 second delay
caused decay in the STM


Baddeley and Hitch 1974
› Based on the Multi-Store Model

Challenges the idea that Short Term
Memory is a single store
› This model shows different ways the Short
Term Memory creates and recalls Long Term
Memories
Encoding
Long-Term

The Central Executive:
› “Controlling system” which controls the other
“slave systems”
› Processes sensory information
› Most important function is attentional control
 This tells your mind what to focus on
 The Automatic Level: Based on habit and controlled
by stimuli from the environment
 The Supervisory Attentional Level: Deals with
emergencies or creates new strategies when old ones
are no longer sufficient
 You are aware of this attention

Episodic Buffer
› Temporary, unconscious storage
› Imagine having to consciously remember
the sound of a band, or a landscape
› The information has already been processed
in other parts of the brain, and will
temporarily stay in the episodic buffer until
you need it

Phonological Loop
› Two components
› Articulatory Control System: (inner voice)
converts written information into a verbal form
 When you read a word, or phone number, you are
able to “repeat it”
 When you are preparing to speak, the memory of
how to pronounce words occurs here
› Phonological Store: (inner ear) Holds speech-
based material in a phonological form. You can
recall sounds that you have heard

Visuospatial Sketchpad
› Recall of visual-spatial information
› Processes it from sensory information to long
term memory

http://www.youtube.com/watch?v=Zaa
5w8cIxXI

Dual-Task experiments
› Baddeley and Hitch (1974)
› Asked participants to attempt to read and
memorize a prose while also remembering a
list of numbers
› This is almost impossible, because it would
require the same component of short term
memory
However, we are able to multi-task
 This is because if the activity involves
multiple components, we are able to do
both at once

› It is easier to perform a visual and a verbal
task at the same time rather than two visual
or two verbal tasks

Baddley and Hitch 1974
› When the participants were asked to
verbally answer a true/false question and
memorize a set of numbers, they were able
to do so
› Although there is a slight delay as the
number of digits increased, it was not
significant
› This is because memorizing digits occurs in
the phonological loop, and reasoning
occurs in the central executive
Long Term Memory
Explicit/Declarative
memories
Semantic
Memories
(memory of
facts)
WHAT
.
Episodic
Memories
(memory of
events) .
WHEN
Implicit/Non-Declarative
Memories
Procedural
Memories
(memory of how
to do things)
HOW
Emotional
Memories
(memory of how
emotional states)
.
HOW
Long Term Memory is divided into two
systems, explicit memory and implicit
memory
 Explicit Memory: Fact based memories
the we are consciously aware of

› Semantic Memory: General knowledge
 Ms. C is a teacher
› Episodic Memory: Memory for personal
experiences and events
 I saw Ms. C this morning

Implicit Memory: Memories we are not
consciously aware of
› Procedural Memory: Non-Conscious memory
for skills, habits, actions
› Emotional Memory: How to react
emotionally
 Crying during a sad movie
 Feeling fear in a haunted house

The Hippocampus plays a role in the
formation of explicit memories
› Kandel found that people with hippocampal
damage can no longer form now explicit
memories but can form and recall implicit
memories

The Amygdala plays a role in the
formation of implicit memories
› Neuroscientist LeDoux has found that certain
memories have emotional significance,
which is why we remember them better

Biological factors of memory
› Eric Kandel
› Researched memory at the cellular level
› As a person learns, there are changes in the
synapses of the brain
› As we learn, neurons grow more connections
and form neural networks
Neurologist who studied him – Oliver Sacks
2007
 Clive suffered from the most extensive
amnesia ever recorded

› He suffered from Retrograde(loss of previous
memories) and Anterograde (loss of ability to
make new memories) amnesia
Clive had suffered brain damage to his
hippocampus and frontal lobe regions
 He could not form any new memories, even
for a moment


Wearing was unable to transfer new
information into his long-term memory
› He could still remember how to play the
piano and conduct music, like he could
before his illness – part of his implicit memory
› Still felt affection and love for his wife
 Wearing’s amygdala was not damaged,
therefore his implicit memories remained intact

Evidence of a distributed memory system

Studied by Milner and Scoville 1957
› Because of a head injury at 9 years old, he
began to suffer from seizures
› Dr’s removed a portion of temporal lobe,
including the hippocampus, to stop the seizures

Became unable to form new memories –
anterograde amnesia
› He cannot remember faces of those he meets,
or remember books he reads
› However, HM had his previous memories

In 1997 his brain was studied with an MRI
scanner
› Showed damage to the hippocampus and
amygdala
› This supports the theory that these areas are
responsible for formation of new memories