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Domain specificity in face perception (Kanwisher, 2000). Betty Tijms & Kim Huijpen. Outline. Introduction Domain-specificity view Domain-general view Conclusion Discussion & suggestions for further research. Two views on face perception. Domain-specificity view
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Domain specificity in face perception (Kanwisher, 2000) Betty Tijms & Kim Huijpen
Outline • Introduction • Domain-specificity view • Domain-general view • Conclusion • Discussion & suggestions for further research
Two views on face perception • Domain-specificity view • Distinct mechanisms for various cognitive functions • A module for processing faces in particular • Domain-general view • General mechanism for different domains • Mechanisms can operate on nonface stimuli as well
Prosopagnosia (face blindness) • Patients are unable to recognize familiar faces • They can recognize objects • Mostly a result from lesions of both occipital and temporal lobe where the FFA resides
Fusiform Face Area (FFA) • A region in the fusiform gyrus • Is activated when subjects view faces (fMRI, scalp ERP’s, MEG and single cell recordings)
Arguments for domain-specificity • Face recognition is more disrupted by inversion than object recognition • ‘Holistic’ advantage for face perception • Double dissociation: Prosopagnosia and reverse Prosopagnosia (CK)
Case of CK • CK is severely impaired at reading and object recognition • Face recognition seems relatively unimpaired
Case of CK • CK is severely impaired at reading and object recognition • Face recognition seems relatively unimpaired
Arguments for domain-specificity (2) • FFA activated when subjects view faces • Four times as high when distinguishing between familiar faces than between familiar hands • Evolutionary advantage to have a face-recognition module
Arguments for Domain-general mechanisms • The FFA does not exclusively respond to faces • Prosopagnosia does not exclusively affect face recognition
Ambiguous arguments • Higher order features • Evolutionary view
Conclusions • Kanwisher concludes in favor of domain specificity • Results from other research make this distinction between the two views difficult: • Results Steeves et al. (2005), Rossion et al. (2003), von Kriegstein (2005).
Other findings in relation to face perception • FFA is not exclusively needed in face recognition also occipital face area necessary for face processing • Autism patients show different activations in response to familiar faces in comparison with unfamiliar faces • FFA is also activated with familiar voices (a non visual stimulus!)
Points of Discussion • Both domain specific modules and general mechanisms could play a role in face perception • Could the FFA play a mediating role in recognition of familiar objects (i.e. also faces and sounds)?
Suggestions for future research • How is FFA activated by babies? • Does WJ show comparable activation of FFA in response to sheep as a normal response to faces? • How do activations in the brain differ between CK, WJ (sheepfarmer) and normal subjects? • What is the effect of lesioning FFA of monkeys? • How is FFA activated in response to familiar audio stimuli (voices) in blind subjects?