“ Memory is deceptive because it is colored by today's events. ” (Albert Einstein)

2. “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

3. 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

4. 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 2.5 bits Communication Channel In Out Source: Pollack 1952, 1953

5. It takes time to measure! Than how do we identify objects in 100ms? Multidimensional stimulus identification Egeth Pachella 1969 • Slower • More error prone • Speed and Accuracy decline with dimensionality

6. Collinearity Curvilinearity Detect non-accidental properties Detect Regions and Concavity Symmetry Component Determination Region Geon Parallel Curves Matching & Identification Vertices 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” Edge Extraction

7. Recognition By Components (Cont’) • 36 Geons suggested

8. Effects of temporal association on recognition memory G. Wallis, HH Bulthoff 2001 We are continuously associating views of objects to support later recognition.

9. Morphing visual memories through gradual associationsS. Preminger, D. Sagi, M Tsodyks (unpublished) • How exposure to face stimuli, associated with a previously memorized face , influences the long-term memory of the stored face”

10. Our Research

11. Limited Perception Limited ability to represent in memory Representation in Working Memory 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

12. Representation in Long Term Memory Search (Store) Retrieve 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?

13. Working memory We have limited ability to measure Can we at least maintain a measurement?

14. We cannot remember a measurement! Test your working memory • Find the longest line The Test Ended Jump to next test

15. Study the size of this circle (1) Jump to next test

16. How many circles of the same size do you see? (1) The Test Ended Jump to next test

17. Why was this test successful? Results (1) Jump to next test

18. Study the size of this circle (2) Jump to next test

19. How many circles of the same size do you see?(2) The Test Ended Jump to next test

20. Results (2) Jump to next test

21. Stimuli Stimuli Stimuli Stimuli What is the difference between the tests? • In the second test: • All circles are small • We modify the internal representation based on the stimuli Jump to next test

22. Representation in Working Memory Representation Limited Perception Limited Perception Limited ability to represent in memory Limited ability to represent in memory Representation in Working Memory Representation 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

23. 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?

24. Class A Class B Class C A1 A2 A3 A4 B1 B2 B3 B4 C1 C2 C3 C4 Classes: Objects: 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?

25. 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 We remember discretely • Semi-Discrete • ~7 Categories (?) • Categories of: • Length/Width/Depth • Angle • Ratio • Color

26. Representation in Long Term Memory Search (Store) Retrieve Limited Perception Limited ability to represent in memory Representation in Working Memory Representation Representation 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 • As a result: • Our long term memory is adaptive • We cannot rely on it for continuous measurements

27. 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

28. Could it be thatEinstein was right after all?When he said: “Memory is deceptive because it is colored by today's events.” (Albert Einstein) E=MC2