2. “ Memory is deceptive because it is colored by today's events. ” (Albert Einstein) Memory is deceptive because it is colored by today's events. 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 Source: Pollack 1952, 1953 Communication Channel InOut 3 bits2.5 bits

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

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

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 Morphing visual memories through gradual associations S. Preminger, D. Sagi, M Tsodyks (unpublished) How exposure to face stimuli, associated with a previously memorized face, influences the long-term memory of the stored face ”

10. Our Research

11. Storing a representation We cannot memorize what we cannot perceive We can only store what we have in our working memory Representation in Working Memory StoreStore Representation in Long Term Memory Limited ability to represent in memoryLimitedPerception

12. 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 Working Memory RetrieveRetrieve Search (Store) Search (Store) Representation in Long Term Memory Limited ability to represent in memoryLimitedPerception

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

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

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

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. 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 Jump to next test

22. 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 in Working Memory Representation Limited ability to represent in memoryLimitedPerception Representation in Working Memory Representation Limited ability to represent in memoryLimitedPerception

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. 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? A1 Class AClass BClass C A2A3A4B1B2B3B4C1C2C3C4 Classes: Objects:

25. 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

26. 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 Representation in Working Memory Representation RetrieveRetrieve Search (Store) Search (Store) Representation in Long Term Memory Representation Limited ability to represent in memoryLimitedPerception

27. Current work 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 Protocols and measurements for tuning of the brain neural network

28. Could it be that Einstein was right after all? When he said: E=MC 2 “ Memory is deceptive because Memory is deceptive because it is colored by today's events. it is colored by today's events. ” (Albert Einstein)