Occipital face area

Last updated
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.

Contents

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

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

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.

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

Related Research Articles

<span class="mw-page-title-main">Face perception</span> Cognitive process of visually interpreting the human face

Facial perception is an individual's understanding and interpretation of the face. Here, perception implies the presence of consciousness and hence excludes automated facial recognition systems. Although facial recognition is found in other species, this article focuses on facial perception in humans.

<span class="mw-page-title-main">Prosopagnosia</span> Cognitive disorder of face perception

Prosopagnosia, also known as face blindness, is a cognitive disorder of face perception in which the ability to recognize familiar faces, including one's own face (self-recognition), is impaired, while other aspects of visual processing and intellectual functioning remain intact. The term originally referred to a condition following acute brain damage, but a congenital or developmental form of the disorder also exists, with a prevalence of 2.5%. The brain area usually associated with prosopagnosia is the fusiform gyrus, which activates specifically in response to faces. The functionality of the fusiform gyrus allows most people to recognize faces in more detail than they do similarly complex inanimate objects. For those with prosopagnosia, the method for recognizing faces depends on the less sensitive object-recognition system. The right hemisphere fusiform gyrus is more often involved in familiar face recognition than the left. It remains unclear whether the fusiform gyrus is specific for the recognition of human faces or if it is also involved in highly trained visual stimuli. Prosopoagnosic patients are under normal conditions able to recognize facial expressions and emotions.

<span class="mw-page-title-main">Fusiform gyrus</span> Gyrus of the temporal and occipital lobes of the brain

The fusiform gyrus, also known as the lateral occipitotemporal gyrus,is part of the temporal lobe and occipital lobe in Brodmann area 37. The fusiform gyrus is located between the lingual gyrus and parahippocampal gyrus above, and the inferior temporal gyrus below. Though the functionality of the fusiform gyrus is not fully understood, it has been linked with various neural pathways related to recognition. Additionally, it has been linked to various neurological phenomena such as synesthesia, dyslexia, and prosopagnosia.

Visual processing is a term that is used to refer to the brain's ability to use and interpret visual information from the world around us. The process of converting light energy into a meaningful image is a complex process that is facilitated by numerous brain structures and higher level cognitive processes. On an anatomical level, light energy first enters the eye through the cornea, where the light is bent. After passing through the cornea, light passes through the pupil and then lens of the eye, where it is bent to a greater degree and focused upon the retina. The retina is where a group of light-sensing cells, called photoreceptors are located. There are two types of photoreceptors: rods and cones. Rods are sensitive to dim light and cones are better able to transduce bright light. Photoreceptors connect to bipolar cells, which induce action potentials in retinal ganglion cells. These retinal ganglion cells form a bundle at the optic disc, which is a part of the optic nerve. The two optic nerves from each eye meet at the optic chiasm, where nerve fibers from each nasal retina cross which results in the right half of each eye's visual field being represented in the left hemisphere and the left half of each eye's visual fields being represented in the right hemisphere. The optic tract then diverges into two visual pathways, the geniculostriate pathway and the tectopulvinar pathway, which send visual information to the visual cortex of the occipital lobe for higher level processing.

Visual agnosia is an impairment in recognition of visually presented objects. It is not due to a deficit in vision, language, memory, or intellect. While cortical blindness results from lesions to primary visual cortex, visual agnosia is often due to damage to more anterior cortex such as the posterior occipital and/or temporal lobe(s) in the brain.[2] There are two types of visual agnosia: apperceptive agnosia and associative agnosia.

<span class="mw-page-title-main">Inferior temporal gyrus</span> One of three gyri of the temporal lobe of the brain

The inferior temporal gyrus is one of three gyri of the temporal lobe and is located below the middle temporal gyrus, connected behind with the inferior occipital gyrus; it also extends around the infero-lateral border on to the inferior surface of the temporal lobe, where it is limited by the inferior sulcus. This region is one of the higher levels of the ventral stream of visual processing, associated with the representation of objects, places, faces, and colors. It may also be involved in face perception, and in the recognition of numbers and words.

<span class="mw-page-title-main">Colour centre</span> Brain region responsible for colour processing

The colour centre is a region in the brain primarily responsible for visual perception and cortical processing of colour signals received by the eye, which ultimately results in colour vision. The colour centre in humans is thought to be located in the ventral occipital lobe as part of the visual system, in addition to other areas responsible for recognizing and processing specific visual stimuli, such as faces, words, and objects. Many functional magnetic resonance imaging (fMRI) studies in both humans and macaque monkeys have shown colour stimuli to activate multiple areas in the brain, including the fusiform gyrus and the lingual gyrus. These areas, as well as others identified as having a role in colour vision processing, are collectively labelled visual area 4 (V4). The exact mechanisms, location, and function of V4 are still being investigated.

<span class="mw-page-title-main">Fusiform face area</span> Part of the human visual system that is specialized for facial recognition

The fusiform face area is a part of the human visual system that is specialized for facial recognition. It is located in the inferior temporal cortex (IT), in the fusiform gyrus.

In cognitive neuroscience, visual modularity is an organizational concept concerning how vision works. The way in which the primate visual system operates is currently under intense scientific scrutiny. One dominant thesis is that different properties of the visual world require different computational solutions which are implemented in anatomically/functionally distinct regions that operate independently – that is, in a modular fashion.

The greebles are artificial objects designed to be used as stimuli in psychological studies of object and face recognition. They were named by the American psychologist Robert Abelson. The greebles were created for Isabel Gauthier's dissertation work at Yale, so as to share constraints with faces: they have a small number of parts in a common configuration. Greebles have appeared in psychology textbooks, and in more than 25 scientific articles on perception. They are often used in mental rotation task experiments.

<span class="mw-page-title-main">Brain asymmetry</span> Term in human neuroanatomy referring to several things

In human neuroanatomy, brain asymmetry can refer to at least two quite distinct findings:

Prosopamnesia is a selective neurological impairment in the ability to learn new faces. There is a special neural circuit for the processing of faces as opposed to other non-face objects. Prosopamnesia is a deficit in the part of this circuit responsible for encoding perceptions as memories.

Discrete categories of objects such as faces, body parts, tools, animals and buildings have been associated with preferential activation in specialised areas of the cerebral cortex, leading to the suggestion that they may be produced separately in discrete neural regions.

<span class="mw-page-title-main">Superior temporal sulcus</span> Part of the brains temporal lobe

In the human brain, the superior temporal sulcus (STS) is the sulcus separating the superior temporal gyrus from the middle temporal gyrus in the temporal lobe of the brain. A sulcus is a deep groove that curves into the largest part of the brain, the cerebrum, and a gyrus is a ridge that curves outward of the cerebrum.

Visual object recognition refers to the ability to identify the objects in view based on visual input. One important signature of visual object recognition is "object invariance", or the ability to identify objects across changes in the detailed context in which objects are viewed, including changes in illumination, object pose, and background context.

The N170 is a component of the event-related potential (ERP) that reflects the neural processing of faces, familiar objects or words. Furthermore, the N170 is modulated by prediction error processes.

The extrastriate body area (EBA) is a subpart of the extrastriate visual cortex involved in the visual perception of human body and body parts, akin in its respective domain to the fusiform face area, involved in the perception of human faces. The EBA was identified in 2001 by the team of Nancy Kanwisher using fMRI.

<span class="mw-page-title-main">Visual word form area</span> Region of the brain

The visual word form area (VWFA) is a functional region of the left fusiform gyrus and surrounding cortex that is hypothesized to be involved in identifying words and letters from lower-level shape images, prior to association with phonology or semantics. Because the alphabet is relatively new in human evolution, it is unlikely that this region developed as a result of selection pressures related to word recognition per se; however, this region may be highly specialized for certain types of shapes that occur naturally in the environment and are therefore likely to surface within written language.

Prosopometamorphopsia is a visual disorder characterized by altered perceptions of faces. In the perception of a person with the disorder, facial features are distorted in a variety of ways including drooping, swelling, discoloration, and shifts of position. Prosopometamorphopsia is distinct from prosopagnosia, which is characterised by the inability to recognise faces. About 75 cases of prosopometamorphopsia have been reported in the scientific literature. In about half of the reported cases, features on both sides of the face appear distorted. In the other half of cases, distortions are restricted to one side of the face and this condition is called hemi-prosopometamorphopsia.

The face inversion effect is a phenomenon where identifying inverted (upside-down) faces compared to upright faces is much more difficult than doing the same for non-facial objects.

References

  1. ↑ 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.
  2. ↑ 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.
  3. ↑ 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.
  4. ↑ 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.
  5. ↑ 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.
  6. ↑ 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.
  7. ↑ "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.
  8. ↑ 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.
  9. ↑ 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.
  10. ↑ 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.
  11. ↑ 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.
  12. ↑ 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.
  13. ↑ 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.
  14. 1 2 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.
  15. ↑ 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.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.