The document discusses various types and causes of memory disorders. It describes theories of forgetting such as decay and interference. It outlines the multi-store model of memory including sensory, short-term and long-term memory. Various memory disorders are explained like amnesia from brain damage or thiamine deficiency. Dissociative disorders involving repressed memories are also covered. Assessment methods for different memory systems and types of memory loss are presented.

1. Disorders of MemoryDisorders of Memory
Dr. Zahiruddin OthmanDr. Zahiruddin Othman
25/02/200725/02/2007

2. Theories of Forgetting
Decay (fade away)
 The strength of the
connections between
neurons established by
learning fades away over
time
 Storage failure
Interference
 The disruption of the
ability to remember one
piece of information by
the presence of other
information
 Probably because the
retrieval cues for various
memories are similar.
 Retrieval failure
Memory Cues
Cues are stimuli that help
you remember; they are
reminders of an event
Context dependent memory
State-dependent memory
e.g.,. drug, sober
Mood-dependent memory
e.g.,. happy, sad
A helpful retrieval cue matches
fragments of information that
are stored in LTM.
The theory views memory as a
continuum of processing from the
“transient product of sensory
analysis to the highly durable
product of semantic-associative
operations” (Craik & Lockhart)
The greater the depth of
processing, the more “durable” the
memory will be and thus the greater
the retention
Encoding
(forming a memory
code)
Encoding
(forming a memory
code)
Storage
(maintaining encoded
memory over time)
Storage
(maintaining encoded
memory over time)
Retrieval
(recovering information
from memory stores)
Retrieval
(recovering information
from memory stores)
KeyKey ProcessesProcesses
scanner DVD-writer
monitor

3. Sensory Memory
Iconic Memory (vision)
•Capacity: Essentially that of the visual system
•Duration: About 0.5 to 1.0 seconds
•Processing: None beyond raw perceptual processing
Echoic Memory (hearing}
•Capacity: ?
•Duration: About 4 to 5 seconds
•Processing: None beyond raw perceptual processing
Sensory Memory
Iconic Memory (vision)
•Capacity: Essentially that of the visual system
•Duration: About 0.5 to 1.0 seconds
•Processing: None beyond raw perceptual processing
Echoic Memory (hearing}
•Capacity: ?
•Duration: About 4 to 5 seconds
•Processing: None beyond raw perceptual processing
Short-term memory (STM) a.k.a. working memory
•Capacity: About 7 ± 2 "chunks" of information
•Duration: About 18 to 20 seconds
•Processing: information is often encoded verbally
Short-term memory (STM) a.k.a. working memory
•Capacity: About 7 ± 2 "chunks" of information
•Duration: About 18 to 20 seconds
•Processing: information is often encoded verbally
Long-term memory (LTM)
•Capacity: Virtually unlimited
•Duration: Up to a lifetime
•Processing: Information is organized according to
meaning and is associatively linked
Long-term memory (LTM)
•Capacity: Virtually unlimited
•Duration: Up to a lifetime
•Processing: Information is organized according to
meaning and is associatively linked
InputAttention
Storage
Retrieval
Rehearsal
Multi-StoreMulti-Store ModelModel
decay
interference
retrieval
failure
Forgetting

4. Computer MemoryComputer Memory Human MemoryHuman Memory
Unreliable and fallible
High confidence doesn’t
necessarily mean high accuracy
Source problems: we mix up
things that happen to us with
things we hear about, see on TV,
etc.
Memory is constructive and can
be heavily influenced by our prior
beliefs and schemas
When information is stored in the hard
disk, it remain unchanged indefinitely, and
you can retrieve an exact copy.
The original 2-stage model of the Atkinson-Shiffrin memory model (1968); lacking
the "sensory memory" stage, which was devised at a later stage in research

5. Photographic Memory:Photographic Memory:
Luria studied Shereshevski who had an unusual
form of eidetic imagery. He could look at a table
of numbers arranged randomly in rows and
columns for a couple of minutes, after which he
could read the table backward, diagonally, or any
other way by calling up the mental picture.
However, the test was a curse. He had trouble
forgetting what he wanted to
Eidetic imagery:Eidetic imagery:
Some children can hold a complex picture in
mind for a couple of minutes. The ability is rare
in adults and usually disappears by the middle
school years.
Mnemonists:Mnemonists:
Make use of rapid coding schemes.

6. THE REAL GOD OF GAMBLERTHE REAL GOD OF GAMBLER
Professional gin rummy and poker player, the late
Stu Ungar, was said to have had eidetic memoryeidetic memory.
He was able to keep track of every card in a six-
deck blackjack shoe. In 1977 he was bet
$100,000 by Bob Stupak, an owner and designer
of casinos, that he could not count down the last
three decks in a six deck shoe. Ungar won the
bet.
http://en.wikipedia.org/wiki/Stu_Ungar
RAIN MANRAIN MAN
At a restaurant, a waitress is
slightly puzzled when Raymond
says her name and home
phone number. He had read
and memorized up to the letter
G — halfway through G — in
the residential directory of a
phone book the previous night.
Charlie is able to convince the
waitress that Raymond means
well, and she seems slightly
impressed. Later, the waitress
drops a box of toothpicks,
spilling its contents, prompting
Raymond to instantly calculate
the number of toothpicks on
the floor (246). Charlie thinks
his brother is wrong (since the
box is a 250-count size), until
the waitress says that four of
the toothpicks remained in the
box.
http://en.wikipedia.org/wiki/The_Rain_Man
Eidetic memory, photographic memory, or total recall, is the ability to recall images, sounds, or
objects in memory with great accuracy and in seemingly unlimited volume. The word eidetic
(pronounced: /a d t k/) comes from the Greek word είδος (eidos), which means "image" or "form".ɪˈ ɛ ɪ

7. Sensory
Memory
< 5 seconds
Sensory
Memory
< 5 seconds
InputAttention
Storage
Retrieval
Rehearsal
Recent
Memory
Last few days-weeks
Recent
Memory
Last few days-weeks
Remote
Memory
Last few years
Remote
Memory
Last few years
Word List
Memory Test
-recall a list of unrelated
word after 5 minutes
Word List
Memory Test
-recall a list of unrelated
word after 5 minutes
Memory ModelMemory Model Clinical AssessmentClinical Assessment
Events in the
previous days
or weeks
Events in the
previous days
or weeks
Events in the
previous months
or years
Events in the
previous months
or years
LTM>Declarative>LTM>Declarative>Events (episodic memory)Events (episodic memory)
LTM
< lifetime
LTM
< lifetime
Delayed
Memory
Last few minutes
Delayed
Memory
Last few minutes
STM
< 20 seconds
STM
< 20 seconds
Immediate
Memory
Last few seconds
Immediate
Memory
Last few seconds

8. Disorders of Memory:
AmnesiaAmnesia
(loss of memory)
AmnesiaAmnesia
(loss of memory)
AmnesticAmnestic
DisordersDisorders
(organic)
AmnesticAmnestic
DisordersDisorders
(organic)
Paramnesia
(errors of memory)
Paramnesia
(errors of memory)
Dissociative
Disorders
(psychogenic)
Dissociative
Disorders
(psychogenic)
The character Neo experiencesThe character Neo experiences déjà vudéjà vu when he sees a black cat go past twice in awhen he sees a black cat go past twice in a
row. Trinity explains to Neo thatrow. Trinity explains to Neo that "a déjà vu is usually a glitch in the matrix""a déjà vu is usually a glitch in the matrix" whichwhich
occurs when the machines change something inside the matrix. The black cat passedoccurs when the machines change something inside the matrix. The black cat passed
twice when the machines placed brick walls outside all the windows in a buildingtwice when the machines placed brick walls outside all the windows in a building..
EpisodicEpisodic
Semantic
Source
EpisodicEpisodic
Semantic
Source
Confabulation
(unconscious filling up gaps
in memory)
Confabulation
(unconscious filling up gaps
in memory)
Déjà vu
(French; “already seen“)
Déjà vu
(French; “already seen“)
Déjà vécu
(already lived
through)
Déjà senti
(already felt)
Déjà visité
(already visited)
Déjà vécu
(already lived
through)
Déjà senti
(already felt)
Déjà visité
(already visited)
Dis. amnesia
Dis. Fugue
Dis. Identity
Dis. amnesia
Dis. Fugue
Dis. Identity
Retrograde
Anterograde
Retrograde
Anterograde

9. • Syndromes
– Alcoholic blackouts
– Korsakoff syndrome
– Transient global
amnesia
• Causes
– Trauma or surgery
– Drugs: anticonvulsants
– Toxin: lead, mercury,
organophosphate
insecticides, and
industrial solvents
Amnestic Disorders:

10. Memory Loss: Patient "H.M." &Memory Loss: Patient "H.M." &
Damage to the HippocampusDamage to the Hippocampus

11. The Day His World Stood StillThe Day His World Stood Still

12. • Thiamine (B1) cause damage in the
diencephalondiencephalon
– including the thalamus, basal forebrain,
mamillary bodies, and raphe nuclei
• AnterogradeAnterograde amnesia is severe but
incomplete.
– Patients are able to repeat a series of
numbers or objects as they are stated but not
after a recall period.
• RetrogradeRetrograde amnesia is demonstrated by
gaps in patients' memories of recent and
remote past that antedate the onset of
illness.
• These gaps in memory are associated with
confabulationconfabulation
– i.e., filling in of memory gaps with data the
patient can readily recall.
Korsakoff Syndrome:

13. • Localized amnesiaLocalized amnesia
– occurs when patients cannot remember certain time
periods or events such as experiences in battle or
situations of torture.
• Selective amnesiaSelective amnesia
– occurs when the person can recall some, but not all,
of the events during a circumscribed period of time
e.g., a combat veteran can recall only some part of a
series of violent combat experiences.
• Generalized amnesiaGeneralized amnesia
– occurs when patients cannot remember anything in
their lifetime, including their own identity.
• Continuous amnesiaContinuous amnesia
– occurs when patients have no memory of events up
to and including the present time. This means that
patients are alert and aware of their surroundings
but are not able to remember anything.
• Systematized amnesiaSystematized amnesia
– occurs when patients have a loss of memory for
certain categories of information, such as certain
places or persons.
Dissociative Disoders:
Repressed Memories

14. Dissociative Disorders:
DissociativeDissociative
AmnesiaAmnesia
DissociativeDissociative
AmnesiaAmnesia
DissociativeDissociative
FugueFugue
DissociativeDissociative
FugueFugue
DissociativeDissociative
Identity DisorderIdentity Disorder
(multiple personality disorder)
DissociativeDissociative
Identity DisorderIdentity Disorder
(multiple personality disorder)
Lunch (Ranchi) has dissociative identity disorder; whenever
she sneezes, she switches between a sweet innocent girl
with blue hair, and a blonde who commits crimes for fun and
is quick to respond with gunfire when angered (pulling a
machine-gun out from nowhere when needed). Neither of
Lunch’s personalities remembers what the other says or
does, and it is never said if the evil side knows of the
innocent self; however, the innocent Lunch is aware of her
evil side (although she doesn't really seem very concerned
over her presence). http://en.wikipedia.org/wiki/Lunch_
%28Dragon_Ball%29
Unexpected travelUnexpected travel
AmnesiaAmnesia
± New identityNew identity
Unexpected travelUnexpected travel
AmnesiaAmnesia
± New identityNew identity

17. Confabulation
• ‘‘False statements that are not made to deceive,
are typically more coherent than thoughts
produced during delirium”
• It ranges from small distortions on laboratory
tasks to striking bizarre stories that patients tell
in describing their personal histories
• Typically occurs in the context of executive
deficits such as perseveration, poor self-
monitoring, and difficulty with self-initiated
processes

19. Cryptamnesia
"concealed recollection"
• It refers to cases where (apparently)
a person believes that he or she is
creating or inventing something new,
such as a story, poem, artwork, or
joke, but is actually recalling a similar
or identical work which he or she has
previously encountered.
• The Frost King was a short story
written by Helen Keller at the age of
twelve, in 1892, which was an
apparent product of cryptomnesia.
http://en.wikipedia.org/wiki/The_Frost_King

20. Further Reading
• Korsakoff syndrome: http://www.emedicine.com/med/topic2405.htm
• Transient global amnesia: http://www.emedicine.com/neuro/topic380.htm
• Dissociative disorders: http://www.emedicine.com/med/topic3484.htm
• Atkinson-Shiffrin: http://users.ipfw.edu/abbott/120/AtkinsonShifrin.html