Binocular Rivalry and Visual Awareness in Human Extrastriate
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
Talk Outline BACKGROUND METHODS RESULTS CONCLUSION
BACKGROUND
BACKGROUND Monocular Rivalry Examples
BACKGROUND Binocular Rivalry J J Brain 1 Perception 2 Stimuli
BACKGROUND Binocular Rivalry J Brain 1 Perception 2 Stimuli
BACKGROUND Where is rivalry resolved? J LGN PVC ? ? ? • First guess: LGN or PVC • But, single-unit recordings in monkeys…
BACKGROUND Where is rivalry resolved? J LGN PVC FFA PPA FFA = Fusiform Face Area PPA = Parahippocampal Place Area
METHODS
METHODS Creating binocular rivalry
METHODS f. MRI Scans 1. Localizer Scans 2. Rivalry Scans 3. Non-rivalry Scans Four healthy right-handed human subjects, aged 20 -39.
METHODS 1. Localizer Scans § Alternating house and face stimuli § Locate FFA and PPA
Localizer Scan (In actual experiment, stimuli were presented for 16 second intervals. )
METHODS 1. Localizer Scans § Alternating house and face stimuli § Locate FFA and PPA
METHODS 2. Rivalry Scans § Present single rivalry-causing stimulus § Record timing of subject-reported dominant percept
Rivalry Scan
METHODS 2. Rivalry Scans § Present single rivalry-causing stimulus § Record timing of subject-reported dominant percept
METHODS 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. )
METHODS 3. Non-rivalry Scans § Alternating house and face stimuli § Present stimuli in identical temporal sequence reported during rivalry scans
RESULTS
RESULTS 1. Localizer Scans FFA = Fusiform Face Area PPA = Parahippocampal Place Area
RESULTS Localizer Scans – Raw Data FFA = Fusiform Face Area PPA = Parahippocampal Place Area
RESULTS Rivalry Scans – Raw Data FFA = Fusiform Face Area PPA = Parahippocampal Place Area
RESULTS Averaged Transition Data
RESULTS Everything together
CONCLUSION
CONCLUSION What can we conclude? § FFA & PPA are confirmed. § FFA & PPA activity matches perception. § And back to our original question…
CONCLUSION Upper bound on rivalry resolution J LGN PVC FFA PPA FFA = Fusiform Face Area PPA = Parahippocampal Place Area
Executive Summary BACKGROUND METHODS Where is rivalry resolved? Chic glasses + f. MRI. 3 experiments. RESULTS FFA & PPA respond the same for rivalry and non-rivalry. CONCLUSION Rivalry is resolved before these stages of processing.
Questions?
• Picture of cool guy in glasses taken from: http: //bill. innanen. com/ parkinsons/diary 200110. shtml
CONCLUSION 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 Presented by Stan James and Mayumi Koguchi stan@wanderingstan. com koguchischoepf@tiscali. de
CONCLUSION 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 Presented by Stan James and Mayumi Koguchi stan@wanderingstan. com koguchischoepf@tiscali. de
Executive Summary BACKGROUND METHODS RESULTS CONCLUSION Where is rivalry resolved? Stylish glasses, f. MRI FFA & PPA respond the same for rivalry and non. Rivalry is resolved before these stages of processing.
2. Rivalry Scans – Raw Data FFA = Fusiform Face Area PPA = Parahippocampal Place Area
Still not convinced?
Rivalry
Binocular Rivalry J J Brain 1 Perception 2 Stimuli
- Slides: 41