Date post: | 01-Jul-2015 |
Category: |
Health & Medicine |
Upload: | stan-james |
View: | 949 times |
Download: | 2 times |
Binocular Rivalry and Visual Awareness in Human Extrastriate Cortex
Frank Tong, Ken Nakayama, J. Thomas Vaughan, and Nancy KanwisherDepartment of PsychologyHarvard UniversityNeuron, Vol. 21 753-759, October 1998
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
B A C K G R O U N D
B A C K G R O U N D
Monocular Rivalry Examples
B A C K G R O U N D
Binocular Rivalry
Brain
2 Stimuli
1 Perception
B A C K G R O U N D
Binocular Rivalry
Brain
2 Stimuli
1 Perception
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
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
M E T H O D S
M E T H O D S
Creating binocular rivalry
M E T H O D S
fMRI Scans
1. Localizer Scans2. Rivalry Scans3. Non-rivalry Scans
Four healthy right-handed human
subjects, aged 20-39.
M E T H O D S
1. Localizer Scans
Alternating house and face stimuli Locate FFA and PPA
Localizer Scan(In actual experiment, stimuli were presented for 16 second intervals.)
M E T H O D S
1. Localizer Scans
Alternating house and face stimuli Locate FFA and PPA
M E T H O D S
2. Rivalry Scans
Present single rivalry-causing stimulus
Record timing of subject-reported dominant percept
Rivalry Scan
M E T H O D S
2. Rivalry Scans
Present single rivalry-causing stimulus
Record timing of subject-reported dominant percept
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
Non-Rivalry Scan(Stimuli presented in same sequence and duration as reported in rivalry scan.)
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
R E S U L T S
R E S U L T S
FFA = Fusiform Face Area
PPA = Parahippocampal Place Area
1. Localizer Scans
R E S U L T S
Localizer Scans – Raw Data
FFA = Fusiform Face Area
PPA = Parahippocampal Place Area
R E S U L T S
Rivalry Scans – Raw Data
FFA = Fusiform Face Area
PPA = Parahippocampal Place Area
R E S U L T S
Averaged Transition Data
R E S U L T S
Everything together
C O N C L U S I O N
C O N C L U S I O N
What can we conclude?
FFA & PPA are confirmed. FFA & PPA activity matches
perception. And back to our original
question…
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
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.
Questions?
•Picture of cool guy in glasses taken from: http://bill.innanen.com/ parkinsons/diary200110.shtml
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 KanwisherDepartment of PsychologyHarvard UniversityNeuron, Vol. 21 753-759, October 1998
Presented by Stan James and Mayumi [email protected]@tiscali.de
C O N C L U S I O NBinocular Rivalry and Visual Awareness in Human Extrastriate Cortex
Frank Tong, Ken Nakayama, J. Thomas Vaughan, and Nancy KanwisherDepartment of PsychologyHarvard UniversityNeuron, Vol. 21 753-759, October 1998
Presented by Stan James and Mayumi [email protected]@tiscali.de
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
2. Rivalry Scans – Raw Data
FFA = Fusiform Face Area
PPA = Parahippocampal Place Area
Still not convinced?
Rivalry
Binocular Rivalry
Brain
2 Stimuli
1 Perception