Transcript Memory: Introduction - People Server at UNCW

Memory: Introduction
Zara A. Melikyan
(some slides are courtesy of Dr. G.P.Sutton)
February 5, 2015
Lecture Plan:
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Memory: definition, subtypes and processes
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Clinical examples of memory loss - patients H.M. & C.W.
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What is memory loss
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Memory: assessment
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Example of progressive memory loss - Alzheimer’s dementia
Memory: Definition
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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
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Short-Term Memory - limited capacity (7+/-2, or 4-5 elements), limited duration
(18-30 sec). Registers information to which attention is paid. Transient patterns of
neuronal connection in prefrontal & temporal lobes, hippocampus essential for
information consolidation from STM to LTM.
Information is rehearsed and chunked
•
Long-Term Memory - close to unlimited capacity, unlimited duration. More stable
and permanent changes in neuronal connections throughout the brain.
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
LTM
Declarative
Episodic
Nondeclarative
(Procedural)
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
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;
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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;
•
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)
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Accomplished British musicologist, conductor, keyboardist;
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In 1985 (47y.o.) contracted Herpesviral encephalitis (Herpes simplex virus) that attacked his
CNS: hippocampus (transfers STM to LTM), frontal lobes;
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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)
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Intact: 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
- Usually due to injury or disease
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Retrograde amnesia
Loss of memories prior to an event. Disruption of memory
consolidation
•
Anterograde amnesia
Inability to form new memories (e.g. H.M., C.W.)
Study of Memory
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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
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
Dementias have different etiologies: primary - organic brain degeneration (AD), secondary (TBI,
infection, intoxication, etc.).
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Dementia is very 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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Alzheimer’s Dementia named after Aloysius (Alois) Alzheimer, a
German psychiatrist and neuropathologist who identified the first
case of the disease in 1906;
His patient Mrs. Auguste Dete, a 51 year old woman experiencing
symptoms of memory loss, unusual behavioral changes,
hallucinations, delusions, and impaired social functioning;
Post-mortem brain examination by Dr. Alzheimer revealed AD
markers: amyloid plaques, neurofibrillary tangles, and arteriosclerotic
alterations of brain matter.
Alzheimer’s Dementia: Symptoms
Symptoms worsen over time. Symptoms may vary but, at least two of the following
mental functions must be significantly impaired:
Domain
Memory
Symptoms
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
Communication,
language,
comprehension
Inability to understand instructions, follow the logic of moderately complex sentences.
Later: difficulty understanding own sentences, difficulty forming thoughts into words
Poor judgement
Do not recognize consequences of own actions, unable to evaluate appropriateness
of behavior, level of risk. Behavior may become rude, overly friendly, aggressive.
Personal hygiene may be ignored.
Impaired
orientation
Decreased
attention,
increased
restlessness
Visual perception
To time (date, time), place, person
Quickly begin activity, quickly loose interest/wander (safety problems)
Thank you!