1. HCI/ComS 575X: Computational Perception Instructor: Alexander Stoytchev http://www.vrac.iastate.edu/~alexs

2. Phantoms In The Brain HCI/ComS 575X: Computational Perception Iowa State University Copyright © Alexander Stoytchev

3. Readings for Today Ramachandran, V.S. and S. Blakeslee (1998). "Phantoms in the Brain: Probing the Mysteries of the Human Mind", William Morrow, New York. pp. 1-62.

4. Phantoms in the Brain: Probing the Mysteries of the Human Mind by V. S. Ramachandran and Sandra Blakeslee

5. Recommended Book

6. Readings for Next Time New Scientist (2005). Cover story: "Why you have at least 21 senses", January 29, pp. 33-43. P. Bach-y-Rita, C. C. Collins, F. Sauders, B. White, and L. Scadden, (1969), ``Vision substitution by tactile image projection''. Nature, 221, pp. 963-964.``Vision substitution by tactile image projection''

7. Readings for Next Time Andy Clark, (2003). "Who are we?", Ch. 5 in Natural-Born Cyborgs: Minds, Technologies, and the Future of Human Intelligence, Oxford University Press.

8. Why study brain disorders? Option 1: –curiosities –file and forget Option 2: –these syndromes illustrate fundamental principles of how the normal human mind and brain work

9. Example: Number sense These two disorders often occur together –dyscalculia: impairment of the ability to solve mathematical problems –finger agnosia: inability to name ones own fingers “Is it a complete coincidence that both arithmetic operations and finger naming occupy adjacent brain regions, or does it have something to do with the fact we all learn to count by using our fingers in early childhood?” (p. 19)

10. Example: Natural Smile v.s. Smile on Command

11. Example: yawing v.s. voluntary movement

12. Nature v.s. Nurture “To what extent is all this intricate circuitry in the brain specified by your genes or to what extent is it acquired gradually as the result of your early experiences, as an infant interacts with the world?” - Ramachandran and Blakeslee, p.20

13. Modularity v.s. Holism Modularity –Where is it localized? Holism –How does it work?

14. “Where is it localized?” v.s. “How does it work?“

15. Where is “Baywatch” localized? phosphor glowing on the TV screen cathode-ray tube electromagnetic waives transmitted through the air video tape in the TV studio camera recording the actors [http://www.tv-sets.com/Spike_Tv-baywatch.jpg] [See “Phantoms in the brain”, p. 11.]

16. Where is Iowa State University Localized? Ames Beardshear Hall Howe Hall Memorial Union

17. The Phantom Limb Phenomenon

18. Points on the body surface that yielded referred sensations in the phantom hand [From Ramachandran and Blakeslee, p.30]

19. Transfer of other sensations Warmth Cold Vibrations

20. Phantom Pain

21. What causes the phantom Option 1: Sprout of new connections Option 2:Redundancy of existing connections –each neuron is in a dynamic equilibrium with other adjacent neurons

22. What causes the phantom? “… the phantom emerges not from the stump but from the face and jaw, because every time [the person] smiles or moves his face and lips the impulses activate the “hand” are of his cortex creating the illusion that his hand is still there.” (p. 33)

23. Penfield (a.k.a. Sensory) Homunculus

24. And its 3D analog

25. Origins of the word Homunculus: A miniature, fully formed individual believed by adherents of the early biological theory of preformation to be present in the sperm cell.

26. [http://www.pbs.org/saf/1509/images09/cortex.jpg]

27. Motor Homunculus

28. Sensory and Motor Homunculus

29. Mirror Box [http://www.23nlpeople.com/phantom_limb_pain.htm]

30. Mirror Box [http://www.23nlpeople.com/phantom_limb_pain.htm]

31. Other Phantom Phenomena Gaze tinnitus – damage to auditory nerve can cause people to hear ringing noises when looking in a specific direction

32. In-Class Experiments (30 minutes)

33. The Pinocchio Effect

34. The table is part of my arm The experiment is described on page 60 in “Phantoms in the brain”.

35. THE END