Does the Occipital Face Area Contribute to Holistic Face Processing?

Face perception depends on a network of brain areas that selectively respond to faces over non-face stimuli. These face-selective areas are involved in different aspects of face perception, but what specific process is implemented in a particular region remains little understood. A candidate processisholistic face processing, namely the integration of visual information across the whole of an upright face. In this thesis, I report two experimentsthat examine whether the occipital face area (OFA), a face-selective region in the inferior occipital gyrus, performs holistic processing for categorising a stimulus as a face. Both experiments were conducted using online, repetitive transcranial magnetic stimulation (TMS) to disrupt activity in the brain while participants performed face perception tasks. Experiment 1 was a localiser in which participants completed two face identification tasks while receiving TMS at OFA or vertex. Participants’ accuracy decreased for one of the tasks as a result of OFA but not vertex stimulation. This result confirms that OFA could be localised and its activity disrupted. Experiment 2 was a test of holistic processing in which participants categorised ambiguous two-tone images as faces or non-faces while TMS was delivered to OFA or vertex. Participants’ accuracy and response times were unchanged as a result of either stimulation. This result suggests that the OFA is not engaged in holistic processing for categorising a stimulus as a face. Overall, the currentresults are more consistent with previous studies suggesting that OFA is involved in processing of local face features/details rather than the whole face.