Editing Brain (section)

===== Primates =====
{{See also|Human brain}}

{| class="wikitable" align="right" style="margin-left: 10px;"
|+Encephalization Quotient
!Species
!EQ<ref name=Roth2005>{{cite journal |title=Evolution of the brain and Intelligence |last1=Roth |first1=G |last2=Dicke |first2=U |journal=Trends in Cognitive Sciences |volume=9 |issue=5 |pages=250–257 |year=2005 |doi=10.1016/j.tics.2005.03.005 |pmid=15866152|s2cid=14758763 }}</ref>
|-
|Human||7.4–7.8
|-
|[[Common chimpanzee]]||2.2–2.5
|-
|[[Rhesus macaque|Rhesus monkey]]||2.1
|-
|[[Bottlenose dolphin]]||4.14<ref name=Marino>{{cite journal |last=Marino |first=Lori |title=Cetacean Brain Evolution: Multiplication Generates Complexity |journal=International Society for Comparative Psychology |issue=17 |pages=1–16 |year=2004 |url=http://www.cogs.indiana.edu/spackled/2005readings/CetaceanBrainEvolution.pdf |access-date=2010-08-29 |archive-url=https://web.archive.org/web/20180916132752/http://www.cogs.indiana.edu/spackled/2005readings/CetaceanBrainEvolution.pdf |archive-date=2018-09-16 |url-status=dead }}</ref>
|-
|[[Elephant]]||1.13–2.36<ref>{{Cite journal |doi=10.1016/j.brainresbull.2006.03.016 |last1=Shoshani |first1=J |last2=Kupsky |first2=WJ |last3=Marchant |first3=GH |title=Elephant brain Part I: Gross morphology, functions, comparative anatomy, and evolution |journal=Brain Research Bulletin |volume=70 |issue=2 |pages=124–157 |year=2006 |pmid=16782503|s2cid=14339772 }}</ref>
|-
|[[Dog]]||1.2
|-
|[[Horse]]||0.9
|-
|[[Rat]]||0.4
<!--|-
|colspan="2" style="text-align: left;" |EQ relative to the cat as standard species: EQ(cat)=1-->
|-
|}

The [[human brain|brains of humans]] and other [[primate]]s contain the same structures as the brains of other mammals, but are generally larger in proportion to body size.<ref name=Finlay>{{cite journal |year=2001 |title=Developmental structure in brain evolution |journal=Behavioral and Brain Sciences |volume=24 |pages=263–308 |pmid=11530543 |last1=Finlay |first1=BL |last2=Darlington |first2=RB |last3=Nicastro |first3=N |issue=2 |doi=10.1017/S0140525X01003958|s2cid=20978251 }}</ref> The [[encephalization quotient]] (EQ) is used to compare brain sizes across species. It takes into account the nonlinearity of the brain-to-body relationship.<ref name=Roth2005/> Humans have an average EQ in the 7-to-8 range, while most other primates have an EQ in the 2-to-3 range. Dolphins have values higher than those of primates other than humans,<ref name=Marino/> but nearly all other mammals have EQ values that are substantially lower.

Most of the enlargement of the primate brain comes from a massive expansion of the cerebral cortex, especially the [[prefrontal cortex]] and the parts of the cortex involved in [[Visual perception|vision]].<ref>{{cite book|last=Calvin|first=William H.|url=https://archive.org/details/howbrainsthinkev00calv|title=How Brains Think|publisher=BasicBooks|year=1996|isbn=978-0-465-07278-1|edition=1st|location=New York, NY |url-access=registration}}</ref> The visual processing network of primates includes at least 30 distinguishable brain areas, with a complex web of interconnections. It has been estimated that visual processing areas occupy more than half of the total surface of the primate neocortex.<ref name = Sereno1995>{{cite journal |doi=10.1126/science.7754376 |last1=Sereno |first1=MI |last2=Dale |first2=AM |last3=Reppas |first3=AM |last4=Kwong |first4=KK |last5=Belliveau |first5=JW |last6=Brady |first6=TJ |last7=Rosen |first7=BR |last8=Tootell |first8=RBH |year=1995 |title=Borders of multiple visual areas in human revealed by functional magnetic resonance imaging |journal=Science |volume=268 |issue=5212 |pages=889–893 |url=http://www.cogsci.ucsd.edu/~sereno/papers/HumanRetin95.pdf |archive-url=https://web.archive.org/web/20060523153637/http://cogsci.ucsd.edu/~sereno/papers/HumanRetin95.pdf |archive-date=2006-05-23 |url-status=live |pmid=7754376 |bibcode=1995Sci...268..889S}}</ref> The [[prefrontal cortex]] carries out functions that include [[foresight (psychology)|planning]], [[working memory]], [[motivation]], [[attention]], and [[executive functions|executive control]]. It takes up a much larger proportion of the brain for primates than for other species, and an especially large fraction of the human brain.<ref>{{cite book|last=Fuster|first=Joaquín M.|url=https://archive.org/details/prefrontalcortex00fust_846|title=The Prefrontal Cortex|publisher=Elsevier|year=2008|isbn=978-0-12-373644-4|edition=4th |pages=[https://archive.org/details/prefrontalcortex00fust_846/page/n15 1]–7|url-access=limited}}</ref>