Editing Cerebral cortex (section)

===Thickness===
For species of mammals, larger brains (in absolute terms, not just in relation to body size) tend to have thicker cortices.<ref name=CNSVert/> The smallest mammals, such as [[shrew]]s, have a neocortical thickness of about 0.5&nbsp;mm; the ones with the largest brains, such as humans and fin whales, have thicknesses of 2–4&nbsp;mm.<ref name="Saladin"/><ref name="Roberts"/> There is an approximately [[logarithm]]ic relationship between brain weight and cortical thickness.<ref name=CNSVert>{{cite book |title=The central nervous system of vertebrates, Volume 1 |publisher=Springer |year=1998 |isbn=978-3-540-56013-5 |pages=2011–2012 |vauthors=Nieuwenhuys R, Donkelaar HJ, Nicholson C}}</ref>
[[Magnetic resonance imaging of the brain]] (MRI) makes it possible to get a measure for the thickness of the human cerebral cortex and relate it to other measures. The thickness of different cortical areas varies but in general, sensory cortex is thinner than motor cortex.<ref>{{cite journal | vauthors = Kruggel F, Brückner MK, Arendt T, Wiggins CJ, von Cramon DY | title = Analyzing the neocortical fine-structure | journal = Medical Image Analysis | volume = 7 | issue = 3 | pages = 251–264 | date = September 2003 | pmid = 12946467 | doi = 10.1016/S1361-8415(03)00006-9 | hdl-access = free | hdl = 11858/00-001M-0000-0010-9C60-3 }}</ref> One study has found some positive association between the cortical thickness and [[intelligence]].<ref>{{cite journal | vauthors = Narr KL, Woods RP, Thompson PM, Szeszko P, Robinson D, Dimtcheva T, Gurbani M, Toga AW, Bilder RM | title = Relationships between IQ and regional cortical gray matter thickness in healthy adults | journal = Cerebral Cortex | volume = 17 | issue = 9 | pages = 2163–2171 | date = September 2007 | pmid = 17118969 | doi = 10.1093/cercor/bhl125 | doi-access = free }}</ref>
Another study has found that the [[somatosensory cortex]] is thicker in [[migraine]] patients, though it is not known if this is the result of migraine attacks, the cause of them or if both are the result of a shared cause.<ref>{{cite journal | vauthors = DaSilva AF, Granziera C, Snyder J, Hadjikhani N | title = Thickening in the somatosensory cortex of patients with migraine | journal = Neurology | volume = 69 | issue = 21 | pages = 1990–1995 | date = November 2007 | pmid = 18025393 | pmc = 3757544 | doi = 10.1212/01.wnl.0000291618.32247.2d }}</ref><ref>{{cite news | vauthors = Paddock C |title=Migraine Sufferers Have Thicker Brain Cortex |work=[[Medical News Today]] |url=http://www.medicalnewstoday.com/articles/89286.php |date=2007-11-20| url-status = live| archive-url = https://web.archive.org/web/20080511153657/http://www.medicalnewstoday.com/articles/89286.php| archive-date = 2008-05-11}}</ref>
A later study using a larger patient population reports no change in the cortical thickness in patients with migraine.<ref>{{cite journal | vauthors = Datta R, Detre JA, Aguirre GK, Cucchiara B | title = Absence of changes in cortical thickness in patients with migraine | journal = Cephalalgia | volume = 31 | issue = 14 | pages = 1452–1458 | date = October 2011 | pmid = 21911412 | pmc = 3512201 | doi = 10.1177/0333102411421025 }}</ref>
A genetic disorder of the cerebral cortex, whereby decreased folding in certain areas results in a [[microgyrus]], where there are four layers instead of six, is in some instances seen to be related to [[dyslexia]].<ref>{{cite journal | vauthors = Habib M | title = The neurological basis of developmental dyslexia: an overview and working hypothesis | journal = Brain | volume = 123 Pt 12 | issue = 12 | pages = 2373–2399 | date = December 2000 | pmid = 11099442 | doi = 10.1093/brain/123.12.2373 | doi-access = free }}</ref>