Memory: Introduction
Zara A. Melikyan
(some slides are courtesy of Dr. G.P.Sutton)
Lecture Plan:
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Memory: definition, subtypes, and processes
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Memory: assessment
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What is memory loss
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Clinical examples of memory loss - patients H.M. & C.W.
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Example of progressive memory loss - Alzheimer’s dementia
Memory: Definition
Memory is the process in which information is:
- Encoded - receiving, processing, combining information
- Stored - creation of permanent record of encoded information
- Retrieved - calling back the stored information to use in activity
Temporal Memory Organization
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Sensory Memory - limited capacity 12 elements (G.
Sperling), limited duration (hundreds of milliseconds).
Registers all the sensory information.
- Iconic
- Echoic
- Haptic
•
Short-Term Memory - limited capacity (7+/-2, or 4-5
elements), limited duration (18-30 sec). Registers information
to which attention is paid. Information is rehearsed and
chunked
•
Long-Term Memory - close to unlimited capacity, unlimited
duration.
Memory Models
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Atkinson-Shiffrin Model (1968)
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Baddeley & Hitch Model of Working Memory (1974)
Types of Long-Term
Memory
Long-term
memory (LTM)
Non-declarative
(Procedural)
Declarative
Episodic
Semantic
Skill
Learning
Priming
Conditioning
LTM:
Declarative vs. Nondeclarative
•
Declarative memory
- Memory that can be stated or described
- Capital of Italy
•
Nondeclarative (Procedural)
- Memory about perceptual/motor procedures
- Demonstrated via performance (not conscious recollection)
- Riding a bicycle
Declarative:
Episodic vs. Semantic
•
Episodic
- Detailed autobiographical memory
-15th birthday party
•
Semantic
- Generalized declarative memory
- Facts and information acquired through learning
- Capital of Italy
Nondeclarative:
Skill Learning vs. Priming vs. Conditioning
•
Skill Learning
Learning how to perform a task by repeating a process
May include:
- Sensorymotor skills (mirror tracing)
- Perceptual skills (reading mirror-reversed text)
- Cognitive skills (planning and problem-solving)
Nondeclarative:
Skill Learning vs. Priming vs. Conditioning
•
Priming
- Change in how you process a stimulus (e.g. word,
picture) because you have seen it (or something
similar) previously
- Does not require declarative memory (intact in H.M.)
Nondeclarative:
Skill Learning vs. Priming vs. Conditioning
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Conditioning
Involves relationships between events
Associative learning
- Classical conditioning. Association is formed between
two previously unrelated stimuli. Pavlov’s dogs.
- Instrumental/operant conditioning. Association is
formed between behavior and cosenquences. Skinner box.

http://www.youtube.com/watch?v=TtfQlkGwE2U
Study of Memory
•
Tests:
- Verbal: word lists, paragraphs
- Visual: shapes, objects, scenes
- Tactile, audial, memory for smells
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Learning and immediate retrieval, delayed recall,
recognition
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Recency and Primacy Effects
Patient 1:
Henry Gustav Molaison (1926-2008)
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The case of H.M. is widely studied and published on. Played
important role in cognitive neuropsychology of memory;
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Suffered intractable epilepsy: partial seizures, after 16y.o.
tonic-clonic seizures;
•
Source of epileptic discharge - left and right medial temporal
lobes;
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1953 (27 y.o.) bilateral medial temporal lobe resection hippocampi, amygdalae, enthorhinal cortex, anterolateral
temporal cortex. Most structures were not functional;
Patient 1:
Henry Gustav Molaison (1926-2008)
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After the surgery: epilepsy is controlled, severe memory impairment:
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Severe anterograde amnesia: explicit & semantic memory;
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Moderate temporary-graded retrograde amnesia: could not
remember most events 1-2 years prior and some events 11 years
prior to surgery;
•
Intact: working memory, procedural memory;
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At the end of life: worked crossword puzzles, able to fill in answers to
cues related to pre-surgery knowledge, able to modify old memories
with new information;
•
Resided in care institute 1953-2008. Sliced brain in UCSD.
Patient 2:
Clive Wearing (born 1938)
•
•
Accomplished British musicologist, conductor, keyboardist
In 1985 (47y.o.) contracted Herpesviral encephalitis (Herpes
simplex virus) that attacked his CNS: hippocampus (transfers
STM to LTM), frontal lobes;
Patient 2:
Clive Wearing (born 1938)
Profound total amnesia:
- Severe anterograde amnesia (unable to form new
memories, his memory lasts 7-30 seconds),
- Moderate-severe retrograde amnesia (cannot recall
aspects of past memories, knows that he has children but
does not remember their names, loves his second wife),
- Unable to associate memories effectively,
- Unable to control emotions (labile mood) (e.g. shakes
spasmodically after music stops)
Patient 2:
Clive Wearing (born 1938)
Intact
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Procedural memory (knows how to play the piano, conduct
an orchestra);
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Can learn new practices and very few new facts not from
episodic memory but by procedural memory (e.g. after
having watched a video multiple times he is able to
anticipate parts of it).
http://www.youtube.com/watch?v=Lu9UY8Zqg-Q&feature=related
http://www.youtube.com/watch?v=xCyvzI2aVUo&feature=relmfu
https://www.youtube.com/watch?v=9BrCBq2FY_U
Memory Loss
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Amnesia, from Greek “a” - without, “mnemi" - memory
- Severe memory impairment: inability to encode and retrive info
- Usually due to injury or disease
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Retrograde amnesia
Loss of memories prior to an event. Disruption of memory
consolidation
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Anterograde amnesia
Inability to form new memories (e.g. H.M., C.W.)
Progressive Memory Loss:
Alzheimer’s Dementia
Dementia from Latin: “de” - to depart, “mens” - mind, being out of
one's mind.
General term that describes a wide range of symptoms
associated with a decline in mental ability severe enough to
reduce a person's ability to perform everyday activities. These
symptoms:
- Are not present since birth
- Are a change from previous baseline mental function
- Last more than six months
- Not associated with a loss/alteration of consciousness
- Not due to other medical conditions (e.g. depression)
- Progressive
Progressive Memory Loss:
Alzheimer’s Dementia
Etiology:
 Primary - organic brain degeneration (AD)
 Secondary (TBI, infection, intoxication, etc.)
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Wide spread due to increased life expectancy and
decreased birth: 2010 worldwide 35.6 million, in 2030 65.7
million, in 2050 115.4 million;
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AD 50-75% of all types of dementia;
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Associated with significant cost: lost jobs for patients and
caregivers, medical supplies and drugs, home modification,
care, nursing home
Progressive Memory Loss:
Alzheimer’s Dementia
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Named after Aloysius (Alois) Alzheimer, a German psychiatrist and
neuropathologist who identified the first case of the disease in 1906
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His patient Mrs. Auguste Dete, a 51 year old woman with memory
loss, unusual behavioral changes, hallucinations, delusions, and
impaired social functioning
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Post-mortem brain examination: amyloid plaques, neurofibrillary
tangles, and arteriosclerotic alterations of brain matter
https://www.youtube.com/watch?v=9Wv9jrk-gXc
Alzheimer’s Dementia: Symptoms
Domain
Symptoms
Memory
First short-term memory: keeping track of purse, wallet,
keys, paying bills, planning meals and cooking,
remembering appointments, where car is parked, the route
to home
Long-term memory: own biography, names and faces of
family members
Abstraction,
planning
Lose the ability to perform familiar tasks, plan activities, and
draw simple conclusions from facts
Inability to understand instructions, follow the logic of
Communication,
moderately complex sentences. Later: difficulty
language,
understanding own sentences, difficulty forming thoughts
comprehension
into words
Do not recognize consequences of own actions, unable to
evaluate appropriateness of behavior, level of risk. Behavior
Poor judgement
may become rude, overly friendly, aggressive. Personal
hygiene may be ignored.
Alzheimer’s Dementia: Symptoms
Domain
Symptoms
Impaired orientation
To time (date, time), place, person
Decreased attention,
increased restlessness
Quickly begin activity, quickly loose
interest/wander (safety problems)
Visual perception
Behavioral changes,
psychosis
Lose interest in once-pleasurable
activities, become passive, depressed
(20-30%), anxious (20%). Delusions,
suspicion, paranoia, hallucinations.
Sleep disturbances: insomnia, sleep
interruptions. Disinhibition, impulsivity,
agitation, balance problems, tremor,
troubles eating and swallowing,
wondering and restlessness.
Alzheimer’s Dementia:
Stages of the Disease
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Subjective Cognitive Decline (SCD) – no
impairment is seen, just subjective feeling that
something is “wrong”
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Mild Cognitive Impairment (MCI) – mild
impairments that do not significantly impair daily
functioning
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Alzheimer’s Disease (AD)
Alzheimer’s Dementia: Treatment
- Prevention
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Treatment is not effective (e.g. AChEIs,)
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Prevention – Modification of life style
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Physical exercise
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Intellectual activity
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Social activity
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Avoid risk factors: TBI, stress, infections, etc.
Main points
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Memory definition
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Temporal memory organization – sensory,
short-term, long-term memory
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Types of long-term memory
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Declarative – non-declarative (procedural)
memory
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Episodic – semantic memory
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Skill learning – priming - conditioning
Thank you!