Fusiform face area

The Fusiform face area (FFA) is a part of the human visual system which seems to specialize in facial recognition, although there is also good evidence that it also processes categorical information about other objects.

Anatomy

The FFA is located in the ventral stream on the ventral surface of the temporal lobe on the fusiform gyrus. It is adjacent to the parahippocampal place area and near the putative extrastriate body area. It is in a slightly different place for each human and displays some lateralization, usually being larger in the right hemisphere.

Discovery

The FFA was discovered and continues to be investigated in humans using Positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) studies. Usually, a participant views images of faces, objects, places, bodies, scrambled faces, scrambled objects, scrambled places and scrambled bodies. This is called a functional localizer. Comparing the neural response between faces and scrambled faces will reveal areas that are face-responsive, while comparing cortical activation between faces and objects will reveal areas that are face-selective.

The human FFA was first described by Justine Sergent in 1992cite journal | author=Sergent J, Ohta S, MacDonald B | title=Functional neuroanatomy of face and object processing. A positron emission tomography study | journal=Brain | year=1992 Feb | pages=15–36 | volume=115 | issue=1 | pmid=1559150 | accessdate= 2007-12-04] and more recently by Nancy Kanwisher in 1997cite journal | author= Kanwisher N, McDermott J, Chun MM | title=The fusiform face area: a module in human extrastriate cortex specialized for face perception | journal=J Neurosci. | year=1997 Jun 1 | pages=4302–11 | volume=17 | issue=11 | pmid=9151747 | accessdate= 2007-12-04] who proposed that the existence of the FFA is evidence for domain specificity in the visual system.

More recently, it has been suggested that the FFA is a processing center for more than just faces. Some groups, including Isabel Gauthier and others, maintain that the FFA is an area for recognizing fine distinctions between well-known objects. Gauthier tested both car and bird experts, and found some activation in the FFA when car experts were identifying cars and when bird experts were identifying birds.cite journal | author=Gauthier I, Skudlarski P, Gore JC, Anderson AW | title=Expertise for cars and birds recruits brain areas involved in face recognition | journal=Nat Neurosci. | year=2000 Feb | pages=191–7 | volume=3 | issue=2 | pmid=10649576 | accessdate= 2007-12-04 | doi=10.1038/72140]

A recent paper by Kalanit Grill-Spector also suggests that processing in the FFA is not exclusive to faces.cite journal | author=Grill-Spector K, Sayres R, Ress D | title=High-resolution imaging reveals highly selective nonface clusters in the fusiform face area | journal=Nat Neurosci. | year=2006 Sep | pages=1177–85 | volume=9 | issue=9 | pmid=16892057 | accessdate= 2007-12-04 | doi=10.1038/nn1745] Although an erratum was later published which brought to light errors in this paper, the information presented nonetheless suggests that those in the field of neuroscience need to rethink their interpretations of the FFA.

Further reading

* McKone et al., Trends in Cognitive Science, 2007
* Carlson, Neil R., Physiology of Behavior, 9th ed., 2007. ISBN:0-205-46724-5
* Bukach, C. M., I. Gauthier, and M. Tarr. 2006. Beyond faces and modularity: The power of an expertise framework. TRENDS in Cognitive Sciences 10:159-166.

References