1. Spatial representation and coordinate frames in the brain

2. Hemispheric Neglect Unilateral Neglect: failure to attend to (or represent) sensory information in the left (contralesional) side of space, following right brain parietal injury.

3. Neglect as a deficit in representation Bisiach & Luzzati (1978): imagining a familiar scene (e.g., central square of Milan), from opposite view points

4. Parietal lesions in the right hemisphere are commonly associated with left field neglect Yellow Red Yellow : the lesion typically involves the supramarginal gyrus at the temporoparietal junction Red: variation in the exact extent of the lesion Driver and Mattinagley, NNS, 1998

5. Common tests for Visual Neglect Drawing from memory

6. copying pictures or words

7. crossing out items

8. line bisection

9. reading words

10. “Burning house”: Implicit processing of the unattended side

11. Neglect can be in egocentric and/or allocentric reference frames

12. Egocentric/allocentric neglect

13. Scene/view/object centered neglect Hillis & Caramazza 1990

14. SEF neurons show selectivity for saccade direction Olson 2003

15. An SEF neuron that shows selectivity on bar-left trials regardless of the saccade’s physical direction

16. Posterior parietal cortex – parietal reach region

17. Eye position gain fields in parietal cortex Andersen et al., 1985

18. neurons with head centered RF (in VIP) (Duhamel et al., 1997)

19. Coordinate transformations

20. Neuronal activity in area 5 dependence on eye & hand position fixed eye position fixed hand position 1 sec Buneo et al., 2002

21. What’s the coordinate system of these neurons?

22. PRR neuronal activity: Reach Plans in Eye-Centered Coordinates Target Buttons Initial hand position Initial eye position Same eye position Same hand position

23. optimal target position depends on

24. Tactile-visual processing in peripersonal space

25. Peripersonal space- The immediate space surrounding the body (or a certain body part). Extrapersonal space – unreachable.

26. Visual RF Integrated visual-tactile coding of peripersonal space, centered on body parts Iriki A. et al., Neuroreport 1996 Tactile RF

27. Representation of visual information in hand-based coordinates Graziano MS., PNAS 1999 Tactile RF Visual stimulus trajectory 12341234 Stimulus trajectory Response of neuron (spike/sec)

28. The cell’s response doesn’t depend on fixation position

29. Neurons with multimodal receptive fields were found in areas: -Ventral premotor -Ventral intraparietal (VIP) -Parietal BA 7b, 5 - Putamen

30. M.S. Graziano et al., Science (2000) Postural bimodal neurons in area 5 respond to the seen position of the hand

31. M.S. Graziano et al., Science (2000) The effect of the fake arm

32. The rubber hand illusion It’s mine!

33. Pointing at my hand? Botvinick and Cohen, 1998, Nature

34. The rubber hand illusion in the fMRI scanner

35. The rubber hand illusion

36. Brain activity - 2 subjective rating of the illusion vs. level of PM activity R 2 = 0.3969, P<0.003R 2 = 0.3982, P<0.002 * Also found in R. cerebellum. Linear relationship

37. Makin et al 2007