Occipital face area
| Occipital face area | |
|---|---|
| Details | |
| System | Visual system |
| Location | Occipital lobe |
| Anatomical terms of neuroanatomy | |
The occipital face area (OFA) is a region of the human cerebral cortex which is specialised for face perception. The OFA is located on the lateral surface of the occipital lobe adjacent to the inferior occipital gyrus.[1] The OFA comprises a network of brain regions including the fusiform face area (FFA) and posterior superior temporal sulcus (STS) which support facial processing.
The identification of the OFA emerged from neuroimaging studies, particularly fMRI and PET, which revealed heightened neural activity in response to facial stimuli within this distinct cortical region.
Structure
[edit]Like other regions of cerebral cortex, the OFA is functionally defined by using neuroimaging techniques to localise changes in neural activity in response to different face stimuli.[2] Typically, participants will view different kinds of face stimuli which can be contrasted with scrambled images, letter strings or non-face objects to localise the OFA.[3][4][5] While the exact location of the OFA varies between individuals and depands on the specific paradigm used, it usually corresponds to Brodmann areas 18 or 19.[6] The OFA is positioned in close proximity to the FFA and the STS, forming a complex network crucial for facial processing.
Function
[edit]The OFA is believed to be functionally necessary for some face computations. Lesion studies using patients with prosopagnosia show that brain damage overlapping with the OFA is associated with impaired facial recognition.[7] TMS studies using healthy participants have shown that temporary inactivation of the OFA can produce deficits in various aspects of face perception including face recognition, face identity perception and facial feature processing.[8][9][10]
Research indicates that the OFA primarily engages in the early stages of face perception, focusing on the structural aspects of faces, such as contours and basic features. While it is specialized for facial processing, the OFA is not exclusively dedicated to this function, as studies suggest its involvement in processing non-face objects as well. The interaction between the OFA and other face-selective regions contributes to the holistic understanding of facial stimuli.
Compared to lower visual cortical areas such as V1, the OFA is believed to support face processing by representing higher-order features such as faces or facial features compared with lower-order features such as edges or contours. For example, it has been suggested that the OFA may represent faces using a topographic face map whereby neighbouring areas of the cortical surface reflect physically neighbouring regions of a face.[11] These representations likely emerge as a result of feedback connections between neighbouring cortical areas such as the OFA and FFA which provide fine-grained analysis and a general face-template respectively.[12] This suggestion is supported by evidence of reciprocal connectivity between the OFA and FFA, among other regions of visual cortex.[13]
Patient P.S.
[edit]Examining case studies of individuals with lesions to the OFA provides more insight into the functional role of the OFA. Prosopagnosic patients have been essential for this initiative, especially patient P.S., a right handed woman with a lesion extending from the posterior part of the right inferior occipital gyrus into the posterior fusiform gyrus. This lesion left patient P.S. without a right OFA and she exhibited great difficulty with facial recognition in daily life and facial gender discrimination, and could not match unfamiliar faces seen from different viewing angles. Despite the extensive cortical damage she suffered, patient P.S. exhibited a normal right FFA when compared to age matched controls using a standard fMRI localizer.[14] She was unimpaired with basic-level and within-class object discrimination and recognition tasks. [14][15] Results like these demonstrate that face information can still be processed in the right FFA despite the absence of the right OFA, thus suggesting the presence of alternate cortical routes between the early visual cortex and fusiform gyrus.
See also
[edit]References
[edit]- ^ Pitcher, David; Walsh, Vincent; Duchaine, Bradley (April 2011). "The role of the occipital face area in the cortical face perception network". Experimental Brain Research. 209 (4): 481–493. doi:10.1007/s00221-011-2579-1. ISSN 0014-4819. PMID 21318346. S2CID 6321920.
- ^ Rossion, Bruno; Hanseeuw, Bernard; Dricot, Laurence (2012-07-01). "Defining face perception areas in the human brain: A large-scale factorial fMRI face localizer analysis". Brain and Cognition. 79 (2): 138–157. doi:10.1016/j.bandc.2012.01.001. ISSN 0278-2626. PMID 22330606. S2CID 10457363.
- ^ Puce, Aina; Allison, Truett; Asgari, Maryam; Gore, John C.; McCarthy, Gregory (1996-08-15). "Differential Sensitivity of Human Visual Cortex to Faces, Letterstrings, and Textures: A Functional Magnetic Resonance Imaging Study". Journal of Neuroscience. 16 (16): 5205–5215. doi:10.1523/JNEUROSCI.16-16-05205.1996. ISSN 0270-6474. PMC 6579313. PMID 8756449.
- ^ Gauthier, Isabel; Tarr, Michael J.; Moylan, Jill; Skudlarski, Pawel; Gore, John C.; Anderson, Adam W. (2000-05-01). "The Fusiform "Face Area" is Part of a Network that Processes Faces at the Individual Level". Journal of Cognitive Neuroscience. 12 (3): 495–504. doi:10.1162/089892900562165. ISSN 0898-929X. PMID 10931774. S2CID 8469964.
- ^ Yovel, Galit; Kanwisher, Nancy (2005-12-24). "The Neural Basis of the Behavioral Face-Inversion Effect". Current Biology. 15 (24): 2256–2262. doi:10.1016/j.cub.2005.10.072. ISSN 0960-9822. PMID 16360687. S2CID 14905812.
- ^ Pitcher, David; Walsh, Vincent; Duchaine, Bradley (April 2011). "The role of the occipital face area in the cortical face perception network". Experimental Brain Research. 209 (4): 481–493. doi:10.1007/s00221-011-2579-1. ISSN 0014-4819. PMID 21318346. S2CID 6321920.
- ^ "Behavioral Deficits and Cortical Damage Loci in Cerebral Achromatopsia". Cerebral Cortex. 16 (10): 1529. 2006-10-01. doi:10.1093/cercor/bhl065. ISSN 1460-2199.
- ^ Solomon-Harris, Lily M.; Mullin, Caitlin R.; Steeves, Jennifer K. E. (2013-12-01). "TMS to the "occipital face area" affects recognition but not categorization of faces". Brain and Cognition. 83 (3): 245–251. doi:10.1016/j.bandc.2013.08.007. ISSN 0278-2626. PMID 24077427. S2CID 23734197.
- ^ Ambrus, Géza Gergely; Dotzer, Maria; Schweinberger, Stefan R.; Kovács, Gyula (2017-07-11). "The occipital face area is causally involved in the formation of identity-specific face representations". Brain Structure and Function. 222 (9): 4271–4282. doi:10.1007/s00429-017-1467-2. ISSN 1863-2653. PMID 28699028. S2CID 23083539.
- ^ Pitcher, D.; Garrido, L.; Walsh, V.; Duchaine, B. C. (2008-09-03). "Transcranial Magnetic Stimulation Disrupts the Perception and Embodiment of Facial Expressions". Journal of Neuroscience. 28 (36): 8929–8933. doi:10.1523/jneurosci.1450-08.2008. ISSN 0270-6474. PMC 6670866. PMID 18768686.
- ^ Henriksson, Linda; Mur, Marieke; Kriegeskorte, Nikolaus (2015-11-01). "Faciotopy—A face-feature map with face-like topology in the human occipital face area". Cortex. 72: 156–167. doi:10.1016/j.cortex.2015.06.030. ISSN 0010-9452. PMC 4643680. PMID 26235800.
- ^ Rossion, Bruno (April 2008). "Constraining the cortical face network by neuroimaging studies of acquired prosopagnosia". NeuroImage. 40 (2): 423–426. doi:10.1016/j.neuroimage.2007.10.047. ISSN 1053-8119. PMID 18086537. S2CID 1215719.
- ^ Frässle, Stefan; Paulus, Frieder Michel; Krach, Sören; Schweinberger, Stefan Robert; Stephan, Klaas Enno; Jansen, Andreas (January 2016). "Mechanisms of hemispheric lateralization: Asymmetric interhemispheric recruitment in the face perception network". NeuroImage. 124 (Pt A): 977–988. doi:10.1016/j.neuroimage.2015.09.055. ISSN 1053-8119. PMID 26439515. S2CID 7009210.
- ^ a b Rossion, B. (2003-11-01). "A network of occipito-temporal face-sensitive areas besides the right middle fusiform gyrus is necessary for normal face processing". Brain. 126 (11): 2381–2395. doi:10.1093/brain/awg241. ISSN 1460-2156. PMID 12876150.
- ^ Busigny, Thomas; Graf, Markus; Mayer, Eugène; Rossion, Bruno (2010-06-01). "Acquired prosopagnosia as a face-specific disorder: Ruling out the general visual similarity account". Neuropsychologia. 48 (7): 2051–2067. doi:10.1016/j.neuropsychologia.2010.03.026. ISSN 0028-3932. PMID 20362595. S2CID 31665053.