Transcript Models of Memory

Models of Memory
Introduction to Cognitive Science
Lecture 7: Memory/Sleep
September 29, 2009
Lecture Overview
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The Modal Model (Atkinson & Shiffrin)
ACT* Model (Anderson)
Working Memory Model (Baddeley)
Change Blindness
The Hippocampus
Sleep & Memory
MODELS OF MEMORY
The Modal Model (Atkinson & Shiffrin)
STIMULUS INPUT
e.g. Visual (iconic)
Auditory (echoic), etc.
Sensory
Memory
Some Control Processes:
Rehearsal, Coding,
Decisions, Retrieval
Strategies
RESPONSE
OUTPUT
Short-term
Memory
RETRIEVAL
ENCODING
Long-term
Memory
Figure 5.3, p 134 in text
ACT* Model: Adaptive Control of Thought (Anderson)
External Environment
Encoding
Performance
Working
Memory
Storage
Match
Retrieval
Declarative
Memory
Figure 5.4, p 136 in text
Execution
Production
Memory
The Working Memory Model (Baddeley)
Visuo-spatial Sketchpad
Processing of Visual
Information
Executive Control System
Supervises and controls
processes
Articulatory Loop
Rehearsal and processing of
auditory information
Figure 5.5, p 138 in text
TESTING THE CAPACITY OF VISUAL WORKING
MEMORY:
CHANGE BLINDNESS
Occurs when major changes to a visual scene go unnoticed by the observer.
Pay Attention….
Change Blindness
Differences between the two images can be
detected only if we attend to one of the changing
objects.
This experiment demonstrates that we memorize
only very little information from visual scenes.
We typically use visual scenes as our “external
memory” rather than filling our working memory
with a large amount of scene information.
The Hippocampus
Long-Term Memory
Learning
Navigation
THE HIPPOCAMPUS =
Dentate Gyrus, CA1-CA3, & Subiculum
Marjor input from Entorhinal Cortex
which is  other brain areas such as
the Prefrontal Cortex
Information Flow:
Entorhinal Cortex 
Dentate Gyrus
CA3CA1
Subiculum
Neurogenesis: birth of new neurons
Highly active throughout development
Also adult hippocampal neurogenesis
(dentate gyrus)!
What might this mean for learning and
memory?
Hippocampal Damage
• Retrograde Amnesia: loss of memories before
damage to the hippocampus
• Anterograde Amnesia: inability to form new
memories
• Some causes: aging, Alzheimer’s disease,
stress, temporal lobe epilepsy
Patient H.M.
Patient H.M.
After Surgery for Temporal
Lobe Epilepsy
Anterograde Amnesia:
Intact working and procedural memory
Could not commit to long-term
SOME Retrograde Amnesia:
Couldn’t remember 3–4 -day prior to
surgery, + some events up > 11 years
prior
Able to commit new motor skills to
long-term memory without actually
remembering learning them
http://images.google.com/imgres?imgurl=http://dspace.mit.edu/bitstream/handle/1721.1/45580/9-10Spring-2004/NR/rdonlyres/Brain-and-Cognitive-Sciences/9-10Spring-2004/8AFEA93F-9C52-42E5-B967211CCD2AA287/0/chp_9_10_hip_enc.jpg&imgrefurl=http://dspace.mit.edu/bitstream/handle/1721.1/45580/9-10Spring-2004/OcwWeb/Brain-and-Cognitive-Sciences/9-10Spring2004/CourseHome/index.htm&usg=__baapQ1i44dpgT7ZDQuuBuOVnwnw=&h=307&w=350&sz=26&hl=en&start=2&um=1&tbnid=n5pajUYXebb7tM:&tbnh=105&tbnw=120&prev=/images%3Fq%3Dcoronal%2Bhippocampal%2Bhuman%26hl%3Den%26client%3Dfirefoxa%26rls%3Dorg.mozilla:en-US:official%26sa%3DG%26um%3D1
Sleep & Memory Consolidation
• Born & Marshall The contribution of sleep to
hippocampus-dependent memory
consolidation
• MP Walker
• Stickgold
SLEEP: Overview
Relaxed Wakefulness
NREM Stage 1
Sleep Can Be Divided Into:
NREM Stage 2
•NREM (Stages 1-4)
NREM Stage 3, 4/Slow Wave Sleep
Delta Waves
•REM
Different stages are identified
using EEG
REM
NREM & REM cycle about
every 90 minutes
Early in the night:
NREM 3 & 4 dominate
Later in the night:
Stage 2 and REM dominate
Matthew P. Walker* and Robert Stickgold* Sleep-Dependent Learning
and Memory Consolidation Neuron, Vol. 44, 121–133, Sept 30, 2004
Neurobiology of
Sleep Regulation
Many subcortical regions are involved:
•Thalamus
•Hypothalamus
•Pons
Dreaming also involves:
•Cortical: Prefrontal and Posterior
(vision)
•Subcortical: limbic (emotion)
Some key neurotransmitters:
•Serotonin (5-HT)
•Noradrenaline (NA)
•Acetylcholine (Ach)
3, 679-693 (September 2002)
Hobson & Pace-Schott
Influence of sleep on a motor skill task
(A-C) and a visual skill task (D-F)
(A) Motor performance increase after
sleep
(B) Such performance increase is not
strengthened during subsequent
wake phase
(C) Performance improve is strongly
correlated with amount of stage 2
NREM sleep.
(D) Increased level of visual
performance after one night of
sleep.
(E) Performance iprovement with
regular sleep periods (red) and no
improvement after sleep
deprivation during first night after
training (green).
(F) Improvement is correlated with
amount of slow-wave sleep and
REM sleep.
Replay of
hippocampal
firing during
sleep
Rodent Running path
Hippocampal cells and
location-specific firing
during running
Timecourse of firing
patterns of 10 cells
(rows) during running
Timecourse of firing
patterns of 10 cells
(rows) during REM
Louie & Wilson. Temporally Structured Replay of Awake Hippocampal Ensemble
Activity during Rapid Eye Movement Sleep . Volume 29, Issue 1, January 2001,
Pages 145-156