Study of Memory in

Psychology

• Prepared by
• DR: Shimaa Elgamal
• Lecturer of neurology
• Faculty of medicine
• Kafr Elsheikh university
How Does Memory Work?
An Information-Processing Model
• Encoding: the information gets
Encoding
Encoding:
The information gets into our brains in a way that allows it to be stored
Storage: the information is held in a way that allows it to later be Storage
retrieved
Retrieval: reactivating and recalling the information, producing it
in a form similar to what was encoded.
Retrieval
 1. Encoding and Memory
• There are three main ways in which information can be encoded
(changed):

1. Visual (picture)

2. Acoustic (sound)

3. Semantic (meaning)
 1. Encoding and Memory
For example, how do you remember a telephone number you have looked
up in the phone book?

If you can see it then you are using visual coding, but if you are repeating it
to yourself you are using acoustic coding (by sound).
1. Encoding and Memory

• Evidence suggests that this is the principle coding system in short

term memory (STM) is acoustic coding.
• When a person is presented with a list of numbers and letters, they
will try to hold them in STM by rehearsing them (verbally).
• Rehearsal is a verbal process regardless of whether the list of items
is presented acoustically (someone reads them out), or visually (on a
sheet of paper).
1. Encoding and Memory

• The principle encoding system in long term memory (LTM) appears

to be semantic coding (by meaning). However, information in LTM can
also be coded both visually and acoustically.
 2. Storage and Memory
• This concerns the nature of memory stores,
a. where the information is stored,
b. how long the memory lasts for (duration),
c. how much can be stored at any time (capacity) and
d. what kind of information is held.
The way we store information affects the way we retrieve it.
• There has been a significant amount of research regarding the
differences between Short Term Memory (STM ) and Long Term Memory
(LTM)
2. Storage and Memory
• Most adults can store between 5 and 9 items in their short-term
memory.
• Miller put this idea forward and he called it the magic number 7
• He though that short-term memory capacity was 7 (plus or minus 2)
items because it only had a certain number of “slots” in which items
could be stored.
 2. Storage and Memory

• Short-term memory: Miller didn’t specify the amount of information

that can be held in each slot. Indeed, if we can “chunk” information
together we can store a lot more information in our short-term
memory.

• In contrast the capacity of LTM is thought to be unlimited. Information

can only be stored for a brief duration in STM (0-30 seconds), but LTM
can last a lifetime.
3. Retrieval and Memory
• This refers to getting information out storage. If we can’t remember
something, it may be because we are unable to retrieve it.

• When we are asked to retrieve something from memory, the

differences between STM and LTM become very clear.
 3. Retrieval and Memory
• STM is stored and retrieved sequentially. For example, if a group of
participants are given a list of words to remember, and then asked to
recall the fourth word on the list, participants go through the list in the
order they heard it in order to retrieve the information.

• LTM is stored and retrieved by association. This is why you can

remember what you went upstairs for if you go back to the room where
you first thought about it.
 3. Retrieval and Memory
• Organizing information can help aid retrieval.
• You can organize information in sequences (such as alphabetically, by size or
by time).

• Imagine a patient being discharged form hospital whose treatment involved

taking various pills at various times, changing their dressing and doing
exercises. If the doctor gives these instructions in the order which they must
be carried out throughout the day (i.e. in sequence of time), this will help the
patient remember them.
 Models of Memory Formation
The Atkinson-Shiffrin Model (1968)
1. Stimuli are recorded by our senses and held briefly in sensory memory.

2. Some of this information is processed into short-term memory and

encoded through rehearsal .

3. Information then moves into long-term memory where it can be retrieved

later.
Sensory Memory
• Duration: ¼ to ½ second

• Capacity: all sensory experience (v. larger capacity)

• Encoding: sense specific (e.g. different stores for each sense)

Short term memory
• Duration: 15 and 30 seconds

• Capacity: 7 +/- 2 items

• Encoding: mainly auditory

Long term memory
• Duration: Unlimited

• Capacity: Unlimited

• Encoding: Mainly Semantic (but can be visual and auditory)

 Short Term Memory
Short term memory has three key aspects:
1. limited capacity (only about 7 items can be stored at a time)
2. limited duration (storage is very fragile and information can be lost
with distraction or passage of time)
3. encoding (primarily acoustic, even translating visual information
into sounds).
 Why We Remember What We Remember
Short Term Memory
There are typically six reasons why information is stored in our short
term memory.
1. primacy effect information that occurs first is typically remembered
better than information occurring later. When given a list of words or
numbers, the first word or number is usually remembered due to
rehearsing this more than other information.
2. recency effect - often the last bit of information is remembered
better because not as much time has past; time which results in
forgetting.
3. distinctiveness - if something stands out from information around it, it is
often remembered better. Any distinctive information is easier to remember
than that which is similar or usual.
4. frequency effect - rehearsal, as stated in the first example, results in better
memory. Remember trying to memorize a formula for your math class. The
more you went over it, the better you knew it.
5. associations - when we associate or attach information to other information
it becomes easier to remember. Many of us use this strategy in our professions
and everyday life in the form of acronyms .
6. reconstruction - sometimes we actually fill in the blanks in our memory. In
other words, when trying to get a complete picture in our minds, we will make
up the missing parts, often without any realization that this is occurring.
 working memory
Working memory is STM.
Instead of all information going into one single store, there are different
systems for different types of information.
• Working memory consists of a central executive which controls and co-
ordinates the operation of two subsystems:
1- phonological loop and

2- visuo-spatial sketchpad.
working memory
• Central Executive: Drives the whole system (e.g. the boss of working
memory) and allocates data to the subsystems (VSS & PL). It also
deals with cognitive tasks such as mental arithmetic and problem
solving.

• A. Visuo-Spatial Sketch Pad (inner eye): Stores and processes

information in a visual or spatial form. The VSS is used for navigation.
B. The phonological loop is the part of working memory that deals with
spoken and written material. It can be used to remember a phone number.

It consists of two parts

1. Phonological Store (inner ear) – Linked to speech perception Holds
information in speech-based form (i.e. spoken words) for 1-2 seconds.

2. Articulatory control process (inner voice) – Linked to speech production.

Used to rehearse and store verbal information from the phonological
store.
• The phonological loop is assumed to be responsible for the manipulation of
speech based information.

• The visuo-spatial sketchpad is assumed to be responsible for manipulating

visual images.

• The model proposes that every component of working memory has a

limited capacity, and also that the components are relatively independent of
each other.
Long Term Memory
• Theoretically, the capacity of long term memory could be unlimited,
the main constraint on recall being accessibility rather than availability.

• Duration might be a few minutes or a lifetime.

• Suggested encoding modes are semantic (meaning) and visual

(pictorial) in the main but can be acoustic also.
Long Term Memory
One of the earliest and most influential distinctions was proposed by
Tulving (1972).

He proposed a distinction between episodic, semantic and procedural

memory.
Long Term Memory
• Procedural memory is a part of the long-term memory is responsible
for knowing how to do things, i.e. memory of motor skills.

• It does not involve conscious (i.e. it’s unconscious - automatic)

thought is not declarative.

• For example, procedural memory would involve knowledge of how to

ride a bicycle.
Long Term Memory
• Semantic memory is a part of the long-term memory responsible for
storing information about the world.

This includes knowledge about the meaning of words, as well as

general knowledge.

For example, London is the capital of England. It involves conscious

thought and is declarative.
 Long Term Memory
• Episodic memory is a part of the long-term memory responsible for
storing information about events (i.e. episodes) that we have experienced
in out lives.

It involves conscious thought and is declarative. An example would be a

memory of our 1st day at school
Long Term Memory
• there is a distinction between declarative knowledge and procedural
knowledge.

• Procedural knowledge involves “knowing how” to do things. It

included skills, such as “knowing how” to playing the piano, ride a
bike; tie your shoes and other motor skills. It does not involve
conscious (i.e. automatic) thought. For example, we brush our teeth
with little or no awareness of the skills involved.
Long Term Memory

• Declarative knowledge involves “knowing that”, for example London

is the capital of England, zebras are animals, your mum's birthday etc.
Recalling information from declarative memory involves some degree
of conscious effort – information is consciously brought to mind and
“declared”.
Long Term Memory
The knowledge that we hold in semantic and episodic memories
focuses on “knowing that” something is the case (i.e. declarative).

• For example, we might have a semantic memory for knowing that

Paris is the capital of France, and we might have an episodic memory
for knowing that we caught the bus to college today.
Long Term Memory
Evidence for the distinction between declarative and procedural
memory has come from research on patients with amnesia.
• Typically, amnesic patients have great difficulty in retaining episodic
and semantic information following the onset of amnesia.
Their memory for events and knowledge acquired before the onset of
the condition tends to remain intact, but they can’t store new episodic
or semantic memories. In other words, it appears that their ability to
retain declarative information is impaired.
Long Term Memory
• However, their procedural memory appears to be largely unaffected.
They can recall skills they have already learned (e.g. riding a bike) and
acquire new skills (e.g. learning to drive)
• categorize memory as being explicit, which is defined as that involved in
the conscious recall of information about people, places, and things, or

• • implicit, which is characterized by the nonconscious recall of tasks such

as motor skills.
• • Explicit memory depends on the integrity of temporal lobe and
diencephalic structures such as the hippocampus, subiculum, and
entorhinal cortex.
• • Implicit memory includes simple associative forms of memory, such as
classical conditioning, and nonassociative forms, such as habituation, and
relies on the integrity of the cerebellum and basal ganglia