1. Binocular Rivalry and Visual Awareness in Human Extrastriate Cortex Frank Tong, Ken Nakayama, J. Thomas Vaughan, and Nancy Kanwisher Department of Psychology Harvard University Neuron, Vol. 21 753-759, October 1998 Neuron, Vol. 21 753-759, October 1998

2. M E T H O D S B A C K G R O U N D R E S U L T S C O N C L U S I O N Talk Outline

3. B A C K G R O U N D

4. Monocular Rivalry Examples

5. B A C K G R O U N D Binocular Rivalry Brain 2 Stimuli 1 Perception

6. B A C K G R O U N D Binocular Rivalry Brain 2 Stimuli 1 Perception

7. B A C K G R O U N D Where is rivalry resolved? LGN First guess: LGN or PVC But, single-unit recordings in monkeys… ??? PVC

8. B A C K G R O U N D Where is rivalry resolved? FFA = Fusiform Face Area PPA = Parahippocampal Place Area LGN FFA PPA PVC

9. M E T H O D S

10. Creating binocular rivalry

11. M E T H O D S fMRI Scans 1.Localizer Scans 2.Rivalry Scans 3.Non-rivalry Scans Four healthy right-handed human subjects, aged 20-39.

12. M E T H O D S 1. Localizer Scans  Alternating house and face stimuli  Locate FFA and PPA

13. Localizer Scan (In actual experiment, stimuli were presented for 16 second intervals.)

14. M E T H O D S 1. Localizer Scans  Alternating house and face stimuli  Locate FFA and PPA

15. M E T H O D S 2. Rivalry Scans  Present single rivalry-causing stimulus  Record timing of subject-reported dominant percept

16. Rivalry Scan

17. M E T H O D S 2. Rivalry Scans  Present single rivalry-causing stimulus  Record timing of subject-reported dominant percept

18. M E T H O D S 3. Non-rivalry Scans  Alternating house and face stimuli  Present stimuli in identical temporal sequence reported during rivalry scans

19. Non-Rivalry Scan (Stimuli presented in same sequence and duration as reported in rivalry scan.)

20. M E T H O D S 3. Non-rivalry Scans  Alternating house and face stimuli  Present stimuli in identical temporal sequence reported during rivalry scans

21. R E S U L T S

22. FFA = Fusiform Face Area PPA = Parahippocampal Place Area 1. Localizer Scans

23. R E S U L T S Localizer Scans – Raw Data FFA = Fusiform Face Area PPA = Parahippocampal Place Area

24. R E S U L T S Rivalry Scans – Raw Data FFA = Fusiform Face Area PPA = Parahippocampal Place Area

25. R E S U L T S Averaged Transition Data

26. R E S U L T S Everything together

27. C O N C L U S I O N

28. What can we conclude?  FFA & PPA are confirmed.  FFA & PPA activity matches perception.  And back to our original question…

29. C O N C L U S I O N Upper bound on rivalry resolution FFA = Fusiform Face Area PPA = Parahippocampal Place Area LGN FFA PPA PVC

30. M E T H O D S B A C K G R O U N D R E S U L T S C O N C L U S I O N Executive Summary Where is rivalry resolved? Chic glasses + fMRI. 3 experiments. FFA & PPA respond the same for rivalry and non-rivalry. Rivalry is resolved before these stages of processing.

31. Questions?

33. Picture of cool guy in glasses taken from: http://bill.innanen.com/ parkinsons/diary200110.shtmlbill.innanen.com/ parkinsons/diary200110.shtml

34. C O N C L U S I O N Binocular Rivalry and Visual Awareness in Human Extrastriate Cortex Frank Tong, Ken Nakayama, J. Thomas Vaughan, and Nancy Kanwisher Department of Psychology Harvard University Neuron, Vol. 21 753-759, October 1998 Neuron, Vol. 21 753-759, October 1998 Presented by Stan James and Mayumi Koguchi stan@wanderingstan.com koguchischoepf@tiscali.de

35. C O N C L U S I O N Binocular Rivalry and Visual Awareness in Human Extrastriate Cortex Frank Tong, Ken Nakayama, J. Thomas Vaughan, and Nancy Kanwisher Department of Psychology Harvard University Neuron, Vol. 21 753-759, October 1998 Neuron, Vol. 21 753-759, October 1998 Presented by Stan James and Mayumi Koguchi stan@wanderingstan.com koguchischoepf@tiscali.de

36. M E T H O D S B A C K G R O U N D R E S U L T S C O N C L U S I O N Where is rivalry resolved? Stylish glasses, fMRI FFA & PPA respond the same for rivalry and non. Rivalry is resolved before these stages of processing. Executive Summary

38. 2. Rivalry Scans – Raw Data FFA = Fusiform Face Area PPA = Parahippocampal Place Area

39. Still not convinced?

40. Rivalry

41. Binocular Rivalry Brain 2 Stimuli 1 Perception