<article_title>Brain</article_title>
<edit_user>Tryptofish</edit_user>
<edit_time>Wednesday, August 4, 2010 9:08:59 PM CEST</edit_time>
<edit_comment>/* Primates */ &amp;quot;of&amp;quot;</edit_comment>
<edit_text>The brains of humans and other primates contain the same structures as the brains of other mammals, but are considerably larger in proportion to body size.&lt;ref name=&quot;Finlay&quot; /&gt; Most of the enlargement comes from a massive expansion of the cortex, focusing especially on the parts serving vision and forethought.&lt;ref&gt;Calvin, How Brains Think&lt;/ref&gt; The visual processing network of primates is very complex, including at least 30 distinguishable areas, with a bewildering web of interconnections. Taking all of these together, visual processing makes use <strong>of </strong>more than half of the primate neocortex.&lt;ref name = Sereno1995&gt;&quot;Over half of the neocortex in non-human primates is occupied by visual areas. At least 25 visual areas beyond the primary visual cortex (V1) have been identified with a combination of microelectrode mapping, tracer injections, histological stains, and functional studies (1).&quot; see: and refs contained therein&lt;/ref&gt; The other part of the brain that is greatly enlarged is the prefrontal cortex, whose functions are difficult to summarize succinctly, but relate to planning, working memory, motivation, attention, and executive control.</edit_text>
<turn_user>Edhubbard<turn_user>
<turn_time>Wednesday, August 4, 2010 8:34:22 PM CEST</turn_time>
<turn_topicname>Primate brain</turn_topicname>
<turn_topictext>Actually, it is pretty well established, based on single-unit studies that show visual responsiveness, that more than half the primate neocortex (not brain) is dedicated to vision. See, for example: Sereno, M.I., A.M. Dale, J.B. Reppas, K.K. Kwong, J.W. Belliveau, T.J. Brady, B.R. Rosen, and R.B.H. Tootell (1995) Borders of multiple visual areas in human revealed by functional magnetic resonance imaging. Science 268:889-893. http://www.cogsci.ucsd.edu/~sereno/papers/HumanRetin95.pdf Where they state "Over half of the neocortex in non-human primates is occupied by visual areas. At least 25 visual areas beyond the primary visual cortex (V1) have been identified with a combination of microelectrode mapping, tracer injections, histological stains, and functional studies (1)." Their references for this claim are: M.I. Sereno and J.M. Allman, in The Neural Basis of Visual Function, A.G. Leventhal Ed.(Macmillan, London, 1991), pp. 160-172 J.H. Kaas and L.A. Krubitzer, Neuroanatomy of Visual Pathways and their Retinotopic Organization, B. Dreher and S.R. Robinson Eds. (Macmillan, London, 1991), pp. 302-359 D.J. Felleman and D.C. Van Essen, Cereb. Cortex 1, 1 (1991) M.G.P. Rosa, J.G. Soares, M. Fiorani Jr, R. Gattass, Vis. Neurosci. 10, 827 (1993). In humans, due to the increase in the size of the parietal and pre-frontal cortex, this number is probably lower than in our primate cousins. See, for example, for the cross-species comparisons Van Essen, D.C. Lewis, J.W,. Drury, H.A., Hadjikhani, N., Tootell, R.B., Bakircioglu, M. and Miller, M.I. (2001) Mapping visual cortex in monkeys and humans using surface-based atlases. Vision Research 41: 1359-1378. http://brainmap.wustl.edu/resources/VE_VisRes01.pdf Cheers, Edhubbard (talk) 20:34, 4 August 2010 (UTC) Thanks for that, much better now. There's a big difference between half of the brain and half of the neocortex. --Tryptofish (talk) 21:10, 4 August 2010 (UTC) Sure no problem... I'm renaming this section because it's worth mentioning that the references here, especially by people like Sereno, Felleman, Kaas, etc. are also good refs for the differential expansion of the frontal cortex in humans, relative to our other great ape/primate ancestors. I was going to add the Van Essen paper that I've cited above for the frontal cortex expansion, but there are probably other citations that would be good too (also, I think my ref format was incorrect for this page, but a badly formatted ref is better than none at all). Others who would be relevant to look at here are Patricia Goldman-Rakic, Joaquin Fuster (see his book: The Prefrontal Cortex 978-0123736444) and others who study the function of the pre-frontal cortex. There is some debate about the degree to which human frontal cortex differs from other great apes (see, Semendeferi, K., Lu, A., Schenker, N., and H. Damasio. 2002. Humans and great apes share a large frontal cortex. Nature Neuroscience. 5:272-276.) but there is little doubt that human frontal cortex is larger than in macaques. Another good, general source for these types of things would be Georg F. Striedter and his book Streidter, G.F. (2005). Principles of Brain Evolution Sinauer Associates, Sunderland, MA. ISBN 978-0878938209. Cheers, Edhubbard (talk) 21:36, 4 August 2010 (UTC)</turn_topictext>
<turn_text>Actually, it is pretty well established, based on single-unit studies that show visual responsiveness, that more than half the primate neocortex (not brain) is dedicated to vision. See, for example: Sereno, M.I., A.M. Dale, J.B. Reppas, K.K. Kwong, J.W. Belliveau, T.J. Brady, B.R. Rosen, and R.B.H. Tootell (1995) Borders of multiple visual areas in human revealed by functional magnetic resonance imaging. Science 268:889-893. http://www.cogsci.ucsd.edu/~sereno/papers/HumanRetin95.pdf Where they state "Over half of the neocortex in non-human primates is occupied by visual areas. At least 25 visual areas beyond the primary visual cortex (V1) have been identified with a combination of microelectrode mapping, tracer injections, histological stains, and functional studies (1)." Their references for this claim are: M.I. Sereno and J.M. Allman, in The Neural Basis of Visual Function, A.G. Leventhal Ed.(Macmillan, London, 1991), pp. 160-172 J.H. Kaas and L.A. Krubitzer, Neuroanatomy of Visual Pathways and their Retinotopic Organization, B. Dreher and S.R. Robinson Eds. (Macmillan, London, 1991), pp. 302-359 D.J. Felleman and D.C. Van Essen, Cereb. Cortex 1, 1 (1991) M.G.P. Rosa, J.G. Soares, M. Fiorani Jr, R. Gattass, Vis. Neurosci. 10, 827 (1993). In humans, due to the increase in the size of the parietal and pre-frontal cortex, this number is probably lower than in our primate cousins. See, for example, for the cross-species comparisons Van Essen, D.C. Lewis, J.W,. Drury, H.A., Hadjikhani, N., Tootell, R.B., Bakircioglu, M. and Miller, M.I. (2001) Mapping visual cortex in monkeys and humans using surface-based atlases. Vision Research 41: 1359-1378. http://brainmap.wustl.edu/resources/VE_VisRes01.pdf Cheers, </turn_text>