Transcript “Memory is deceptive because it is colored by today`s events

“Memory is deceptive because it is
colored by today's events.”
(Albert Einstein)
David Hadas, CS TAU
Under the supervision of:
Prof. Nathan Intrator, Dr. Galit Yovel
Agenda
• Distinction
– The magical number 7
– Multidimensional stimulus identification
• Recognition
– RBC
• Memory
– Effects of temporal association on recognition memory
– Morphing visual memories through gradual associations
• Our research
– Working memory
– Long term memory
• Identifying object classes
• Discrete vs. Continuous memory
– Current work
The magical number seven
George A. Miller (1956)
• For unidimensional judgments:
The “span of absolute judgment” is ~7
• We can improve by:
– Making relative judgments
– Increasing dimensionality
– Using successive judgments
3 bits
In
2.5 bits
Communication
Channel
Out
Source: Pollack 1952, 1953
Multidimensional stimulus identification
Egeth Pachella 1969
• Slower
• More error prone
• Speed and Accuracy decline with dimensionality
It takes time
to measure!
Than how do we identify objects in 100ms?
Recognition By Components (RBC)
Irving Biederman (1987)
• Primal Access
– Memory Access
– “The first contact of perceptual input from an isolated
unanticipated object to a representation in memory”
Symmetry
Curvilinearity
Collinearity
Edge Extraction
Detect non-accidental
properties
Detect Regions
and Concavity
Region
Parallel Curves
Vertices
Component Determination
Geon
Matching & Identification
Recognition By Components
• 36 Geons suggested
(Cont’)
Effects of temporal association on recognition memory
G. Wallis, HH Bulthoff 2001
We are continuously associating views
of objects to support later recognition.
Morphing visual memories through gradual associations
S. Preminger, D. Sagi, M Tsodyks (unpublished)
• How exposure to face stimuli, associated with a
previously memorized face , influences the long-term
memory of the stored face”
Our Research
Storing a representation
• We cannot memorize what we cannot perceive
• We can only store what we have in our working memory
Representation in
Long Term Memory
Store
Limited
Perception
Limited ability
to represent in
memory
Representation in
Working Memory
Recalling a representation
• We cannot recall what we cannot perceive
• We can only recall what we have in our working memory
• Do we store as we retrieve?
Representation in
Long Term Memory
Search
Retrieve
(Store)
Limited
Perception
Limited ability
to represent in
memory
Representation in
Working Memory
Working memory
• We have limited ability to measure
• Can we at least maintain a measurement?
Test your working memory
• Find the longest line
We cannot
remember a
measurement!
Jump to next test
The Test Ended
Study the size of this circle
Jump to next test
(1)
How many circles of the same size do you see?
Jump to next test
(1)
The Test Ended
Results
(1)
Why was
this test
successful?
Jump to next test
Study the size of this circle
Jump to next test
(2)
How many circles of the same size do you see?
Jump to next test
(2)
The Test Ended
Results
Jump to next test
(2)
What is the difference between the tests?
•
In the second test:
– All circles are small
– We modify the internal representation based on the stimuli
Stimuli
Stimuli
Stimuli
Jump to next test
Stimuli
A representation in working memory
• Depending on the memory type;
– We have limited ability to reliably store even a single memory
– We change the representation based on the stimuli
Representation
Limited
Perception
Limited ability
to represent in
memory
Representation in
Working Memory
Long term memory
• We seem to have a slight working memory problem
– We cannot reliably remember even a single dimension
• Can we at least trust our long term memory to help out?
How detailed is our long term memory?
• Can you describe a table?
• Can you describe your table at home?
– How do you remember it?
• Can you describe Clinton?
– How do you remember him?
Classes:
Class A
Class B
Class C
Objects:
A1 A2 A3 A4
B1 B2 B3 B4
C1 C2 C3 C4
We remember discretely
• Discrete
–
–
–
–
–
–
–
–
–
Parallel or not
Symmetrical or not
Collinear or not
Curvlinear or not
Type of vertex
Number of edges
Number of vertices
Certain Components
Certain component
arrangements
• Continuous
–
–
–
–
Length/Width/Depth
Angle
Ratio
Color
• Semi-Discrete
– ~7 Categories (?)
– Categories of:
•
•
•
•
Length/Width/Depth
Angle
Ratio
Color
A representation in long term memory
•
We can only store what we have in our working
memory
– We change the representation based on the stimuli
•
•
We seem to store as we search our long term
memory
Representation
Representation in
Long Term Memory
As a result:
– Our long term memory is adaptive
– We cannot rely on it for continuous measurements
Search
Retrieve
(Store)
Representation
Limited
Perception
Limited ability
to represent in
memory
Representation in
Working Memory
Current work
Protocols and measurements
for tuning of
the brain neural network
• We develop a tool and a technique for qualifying and
quantifying the plasticity shown during stimuli morphing
• We study:
– The brain inability to secure preset object representations
– The brain natural and involuntary tendency to modify such
representations based on stimuli
– The affect of a protocol on the internal representation
• We measure plasticity of subjects exposed to a morphing protocol
• We characterize the affecting protocol and the resulting changes
Could it be that
Einstein was right after all?
When he said:
“Memory is deceptive because
it is colored by today's events.”
(Albert Einstein)
2
E=MC