TMS to the 鈥渙ccipital face area鈥?affects recognition but not categorization of faces
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- 作者：Lily M. Solomon-Harris ; Caitlin R. Mullin ; Jennifer K.E. Steeves
- 关键词：Face processing ; FFA ; Fusiform gyrus ; Inferior occipital gyrus ; OFA ; Reverse hierarchy
- 刊名：Brain and Cognition
- 出版年：December, 2013
- 年：2013
- 卷：83
- 期：3
- 页码：245-251
- 全文大小：840 K
文摘
The human cortical system for face perception is comprised of a network of connected regions including the middle fusiform gyrus (鈥渇usiform face area鈥?or FFA), the inferior occipital cortex (鈥渙ccipital face area鈥?or OFA), and the superior temporal sulcus. The traditional hierarchical feedforward model of visual processing suggests information flows from early visual cortex to the OFA for initial face feature analysis to higher order regions including the FFA for identity recognition. However, patient data suggest an alternative model. Patients with acquired prosopagnosia, an inability to visually recognize faces, have been documented with lesions to the OFA but who nevertheless show face-selective activation in the FFA. Moreover, their ability to categorize faces remains intact. This suggests that the FFA is not solely responsible for face recognition and the network is not strictly hierarchical, but may be organized in a reverse hierarchical fashion. We used transcranial magnetic stimulation (TMS) to temporarily disrupt processing in the OFA in neurologically-intact individuals and found participants鈥?ability to categorize intact versus scrambled faces was unaffected, however face identity discrimination was significantly impaired. This suggests that face categorization but not recognition can occur without the 鈥渆arlier鈥?OFA being online and indicates that 鈥渓ower level鈥?face category processing may be assumed by other intact face network regions such as the FFA. These results are consistent with the patient data and support a non-hierarchical, global-to-local model with re-entrant connections between the OFA and other face processing areas.