Visual modularity: Difference between revisions

Revision as of 07:54, 8 May 2013

Revision as of 00:36, 4 October 2013

Line 84:

== Form processing ==

Another clinical case that would a priori suggest a module for modularity in visual processing is visual [[agnosia]]. The well studied patient DF is unable to recognize or discriminate objects<ref name=mishkin>{{cite journal|last=Mishkin|first=Mortimer|coauthors=Ungerleider, Leslie G.; Macko, Kathleen A.|title=Object vision and spatial vision: two cortical pathways|journal=Trends in Neurosciences|year=1983|volume=6|pages=414–417|doi=10.1016/0166-2236(83)90190-X}}</ref> owing to damage in areas of the lateral occipital cortex although she can see scenes without problem – she can literally see the forest but not the trees.<ref name=steeves>{{cite journal|last=Steeves|first=Jennifer K.E.|coauthors=Culham, Jody C.; Duchaine, Bradley C.; Pratesi, Cristiana Cavina; Valyear, Kenneth F.; Schindler, Igor; Humphrey, G. Keith; Milner, A. David; Goodale, Melvyn A.|title=The fusiform face area is not sufficient for face recognition: Evidence from a patient with dense prosopagnosia and no occipital face area|journal=Neuropsychologia|year=2006|volume=44|issue=4|pages=594–609|doi=10.1016/j.neuropsychologia.2005.06.013|pmid=16125741}}</ref> [[Neuroimaging]] of intact individuals reveals strong occipito-temporal activation during object presentation and greater activation still for object recognition.<ref name=grillspector>{{cite journal|last=Grill-Spector|first=Kalanit|coauthors=Ungerleider, Leslie G.; Macko, Kathleen A.|title=The neural basis of object perception|journal=Current Opinion in Neurobiology|year=2003|volume=13|issue=3|pages=399|doi=10.1016/S0959-4388(03)00060-6}}</ref> Of course, such activation could be due to other processes, such as visual attention. However, other evidence that shows a tight coupling of [[perceptual]] and [[physiological]] changes<ref name=sheinberg>{{cite journal|last=Sheinberg|first=DL|coauthors=Logothetis, NK|title=Noticing familiar objects in real world scenes: the role of temporal cortical neurons in natural vision|journal=The Journal of neuroscience : the official journal of the Society for Neuroscience|date=2001 Feb 15|volume=21|issue=4|pages=1340–50|pmid=11160405}}</ref> suggests activation in this area does underpin object recognition. Within these regions are more specialized areas for face or fine grained analysis,<ref name=gauthier>{{cite journal|last=Gauthier|first=I|coauthors=Skudlarski, P; Gore, JC; Anderson, AW|title=Expertise for cars and birds recruits brain areas involved in face recognition|journal=Nature neuroscienceNeuroscience|date=2000 Feb|volume=3|issue=2|pages=191–7|doi=10.1038/72140|pmid=10649576}}</ref> place perception<ref name=epstein>{{cite journal|last=Epstein|first=R|coauthors=Kanwisher, N|title=A cortical representation of the local visual environment|journal=Nature|date=1998 Apr 9|volume=392|issue=6676|pages=598–601|doi=10.1038/33402|pmid=9560155}}</ref> and human body perception.<ref name=downing>{{cite journal|last=Downing|first=PE|coauthors=Jiang, Y; Shuman, M; Kanwisher, N|title=A cortical area selective for visual processing of the human body|journal=Science|date=2001 Sep 28|volume=293|issue=5539|pages=2470–3|doi=10.1126/science.1063414|pmid=11577239}}</ref> Perhaps some of the strongest evidence for the modular nature of these processing systems is the [[double dissociation]] between object- and face (prosop-) agnosia. However, as with color and motion, early areas (see <ref name=pasupathy/> for a comprehensive review) are implicated too, lending support to the idea of a multistage stream terminating in the inferotemporal cortex rather than an isolated module.

== Functional modularity ==