CINXE.COM

<!DOCTYPE html> <html class="client-nojs" lang="en" dir="ltr"> <head> <meta charset="UTF-8"/> <title>Brain - RationalWiki</title> <script>document.documentElement.className="client-js";RLCONF={"wgBreakFrames":!1,"wgSeparatorTransformTable":["",""],"wgDigitTransformTable":["",""],"wgDefaultDateFormat":"dmy","wgMonthNames":["","January","February","March","April","May","June","July","August","September","October","November","December"],"wgRequestId":"Z9-ultIucR6OOXyW_ZeP9wAAAMQ","wgCSPNonce":!1,"wgCanonicalNamespace":"","wgCanonicalSpecialPageName":!1,"wgNamespaceNumber":0,"wgPageName":"Brain","wgTitle":"Brain","wgCurRevisionId":2689385,"wgRevisionId":2689385,"wgArticleId":6188,"wgIsArticle":!0,"wgIsRedirect":!1,"wgAction":"view","wgUserName":null,"wgUserGroups":["*"],"wgCategories":["Pages using DynamicPageList parser function","Bronze-level articles","Biology","Medicine","Science","Anatomy"],"wgPageContentLanguage":"en","wgPageContentModel":"wikitext","wgRelevantPageName":"Brain","wgRelevantArticleId":6188,"wgIsProbablyEditable":!0,"wgRelevantPageIsProbablyEditable":!0,"wgRestrictionEdit":[], "wgRestrictionMove":[],"wgMediaViewerOnClick":!0,"wgMediaViewerEnabledByDefault":!0};RLSTATE={"site.styles":"ready","noscript":"ready","user.styles":"ready","user":"ready","user.options":"loading","ext.cite.styles":"ready","skins.vector.styles.legacy":"ready","mediawiki.toc.styles":"ready"};RLPAGEMODULES=["ext.cite.ux-enhancements","site","mediawiki.page.startup","mediawiki.page.ready","mediawiki.toc","skins.vector.legacy.js","ext.gadget.ReferenceTooltips","mmv.head","mmv.bootstrap.autostart"];</script> <script>(RLQ=window.RLQ||[]).push(function(){mw.loader.implement("user.options@1hzgi",function($,jQuery,require,module){/*@nomin*/mw.user.tokens.set({"patrolToken":"+\\","watchToken":"+\\","csrfToken":"+\\"}); });});</script> <link rel="stylesheet" href="/w/load.php?lang=en&modules=ext.cite.styles%7Cmediawiki.toc.styles%7Cskins.vector.styles.legacy&only=styles&skin=vector"/> <script async="" src="/w/load.php?lang=en&modules=startup&only=scripts&raw=1&skin=vector"></script> <meta name="ResourceLoaderDynamicStyles" content=""/> <link rel="stylesheet" href="/w/load.php?lang=en&modules=site.styles&only=styles&skin=vector"/> <meta name="generator" content="MediaWiki 1.35.6"/> <meta name="description" content="The brain is the chunk of fat that sits at the terminus of the central nervous system and helps coordinate sensory input, motor activity, and behavior. Most animals have something similar to a brain, though the level of complexity differs greatly across taxa. We all have a brain (well, most of us anyway), but only some of us think with it.&#91;citation&#160;NOT needed&#93;"/> <link rel="alternate" type="application/x-wiki" title="Edit" href="/w/index.php?title=Brain&action=edit"/> <link rel="edit" title="Edit" href="/w/index.php?title=Brain&action=edit"/> <link rel="shortcut icon" href="/favicon.ico"/> <link rel="search" type="application/opensearchdescription+xml" href="/w/opensearch_desc.php" title="RationalWiki (en)"/> <link rel="EditURI" type="application/rsd+xml" href="https://rationalwiki.org/w/api.php?action=rsd"/> <link rel="license" href="/wiki/RationalWiki:Copyrights"/> <link rel="alternate" type="application/atom+xml" title="RationalWiki Atom feed" href="/w/index.php?title=Special:RecentChanges&feed=atom"/> <meta property="og:type" content="article"/> <meta property="og:site_name" content="RationalWiki"/> <meta property="og:title" content="Brain"/> <meta property="og:description" content="The brain is the chunk of fat that sits at the terminus of the central nervous system and helps coordinate sensory input, motor activity, and behavior. Most animals have something similar to a brain, though the level of complexity differs greatly across taxa. We all have a brain (well, most of us anyway), but only some of us think with it.&#91;citation&#160;NOT needed&#93;"/> <meta property="og:url" content="https://rationalwiki.org/wiki/Brain"/>  </head> <body class="mediawiki ltr sitedir-ltr mw-hide-empty-elt ns-0 ns-subject mw-editable page-Brain rootpage-Brain skin-vector action-view minerva--history-page-action-enabled skin-vector-legacy"> <div id="mw-page-base" class="noprint"></div> <div id="mw-head-base" class="noprint"></div> <div id="content" class="mw-body" role="main"> <a id="top"></a> <div id="siteNotice" class="mw-body-content"><div id="localNotice" lang="en" dir="ltr"><div id="2025_RationalWiki_.27Oregon_Plan.27_Fundraiser"> <table role="presentation" style="margin: 1em auto 1em auto; width: 100%;"> <tbody><tr> <td style="width: 60%; text-align: left;"><big><center><b><a href="/wiki/RationalWiki:Fundraiser" title="RationalWiki:Fundraiser">2025 RationalWiki 'Oregon Plan' Fundraiser</a></b></center></big> <p><b>There is no RationalWiki without you.</b> We are a small non-profit with no staff—we are hundreds of volunteers who document pseudoscience and crankery around the world every day. We will never allow ads because we must remain independent. We cannot rely on big donors with corresponding big agendas. We are not the largest website around, but <a href="/wiki/RationalWiki:Fundraiser" title="RationalWiki:Fundraiser">we believe we play an important role in defending truth and objectivity</a>. </p> </td> <td style="width: 40%; text-align: center;"><big><b><a href="/wiki/RationalWiki:Fundraiser" title="RationalWiki:Fundraiser">Fighting pseudoscience isn't free</a>.<br />We are 100% user-supported! Help and donate $5, $10, $20 or whatever you can today with <img alt="PayPal Logo.png" src="/w/images/thumb/f/fb/PayPal_Logo.png/61px-PayPal_Logo.png" decoding="async" width="61" height="17" srcset="/w/images/thumb/f/fb/PayPal_Logo.png/92px-PayPal_Logo.png 1.5x, /w/images/thumb/f/fb/PayPal_Logo.png/122px-PayPal_Logo.png 2x" data-file-width="883" data-file-height="244" />!</b></big><a href="https://www.paypal.com/donate/?hosted_button_id=67BJMQC85CUFW" title="Donate via PayPal" rel="nofollow"><img alt="" src="/w/images/thumb/1/10/DonateButton.png/100px-DonateButton.png" decoding="async" width="100" height="32" srcset="/w/images/thumb/1/10/DonateButton.png/150px-DonateButton.png 1.5x, /w/images/thumb/1/10/DonateButton.png/200px-DonateButton.png 2x" data-file-width="759" data-file-height="241" /></a> </td></tr></tbody></table> <div role="progressbar" style="width: 100%; border: 2px solid black; position: relative; padding: 2px; border-radius: 18px;"> <a href="/wiki/RationalWiki:Fundraiser" title="RationalWiki:Fundraiser"><span style="text-shadow: -1px -1px 0 #FFFFFF, 1px -1px 0 #FFFFFF, -1px 1px 0 #FFFFFF, 1px 1px 0 #FFFFFF; color: black; font-size: 125%; position: absolute; left: 0%; margin: 0 0 0 10px"><b>Donations so far: $7608.77</b></span></a><a href="/wiki/RationalWiki:Fundraiser" title="RationalWiki:Fundraiser"><span style="text-shadow: -1px -1px 0 #FFFFFF, 1px -1px 0 #FFFFFF, -1px 1px 0 #FFFFFF, 1px 1px 0 #FFFFFF; color: black; font-size: 125%; position: absolute; right: 0%; margin: 0 10px 0 0"><b>Goal: $10000</b></span></a><div style="height: 28px; border-radius: 14px; background-color: hsl(60.87016,100%,45%); width: 76.0877%;"></div> </div></div></div></div> <div class="mw-indicators mw-body-content"> <div id="mw-indicator-bronze" class="mw-indicator"><a href="/wiki/Category:Bronze-level_articles" title="Category:Bronze-level articles"><img alt="Bronze-level article" src="/w/images/thumb/3/3d/Copperbrain.png/25px-Copperbrain.png" decoding="async" width="25" height="25" style="vertical-align: baseline" srcset="/w/images/thumb/3/3d/Copperbrain.png/38px-Copperbrain.png 1.5x, /w/images/thumb/3/3d/Copperbrain.png/50px-Copperbrain.png 2x" data-file-width="800" data-file-height="800" /></a></div> </div> <h1 id="firstHeading" class="firstHeading" lang="en">Brain</h1> <div id="bodyContent" class="mw-body-content"> <div id="siteSub" class="noprint">From RationalWiki</div> <div id="contentSub"></div> <div id="contentSub2"></div> <div id="jump-to-nav"></div> <a class="mw-jump-link" href="#mw-head">Jump to navigation</a> <a class="mw-jump-link" href="#searchInput">Jump to search</a> <div id="mw-content-text" lang="en" dir="ltr" class="mw-content-ltr"><div class="mw-parser-output"><div class="thumb tright"><div class="thumbinner" style="width:149px;"><a href="/wiki/File:RWWW.png" class="image"><img alt="" src="/w/images/8/85/RWWW.png" decoding="async" width="147" height="121" class="thumbimage" data-file-width="147" data-file-height="121" /></a> <div class="thumbcaption"><div class="magnify"><a href="/wiki/File:RWWW.png" class="internal" title="Enlarge"></a></div>An artist's impression of the brain.</div></div></div> <table class="infobox" cellpadding="1" cellspacing="0" style="float: right; margin: 0 0 0.5em 0.5em; text-align:left; border: 1px solid #33CC00; width:175px;"> <tbody><tr> <td style="font-size: 95%; text-align:center; color:White; background-color:#33CC00"><b>Live, reproduce, die</b><br /><a href="/wiki/Biology" title="Biology"><font size="4" color="White"><b>Biology</b></font></a> </td></tr> <tr> <td style="background-color:#e1ffd6;" align="center"><a href="/wiki/Category:Biology" title="Category:Biology"><img alt="Icon bioDNA.svg" src="/w/images/thumb/d/d1/Icon_bioDNA.svg/100px-Icon_bioDNA.svg.png" decoding="async" width="100" height="100" srcset="/w/images/thumb/d/d1/Icon_bioDNA.svg/150px-Icon_bioDNA.svg.png 1.5x, /w/images/thumb/d/d1/Icon_bioDNA.svg/200px-Icon_bioDNA.svg.png 2x" data-file-width="200" data-file-height="200" /></a> </td></tr> <tr> <td style="font-size: 95%; color:White; background-color:#33CC00; text-align:center;"><b>Life as we know it</b> </td></tr> <tr> <td style="font-size: 95%; background-color:#e1ffd6;"> <ul><li><a href="/wiki/Genetics" title="Genetics">Genetics</a></li> <li><a href="/wiki/Evolution" title="Evolution">Evolution</a></li> <li><a href="/wiki/Cell" title="Cell">Fundamental unit of life: The cell</a></li> <li><a href="/wiki/Zoology" class="mw-redirect" title="Zoology">Zoology</a></li> <li><a href="/wiki/Botany" class="mw-redirect" title="Botany">Botany</a></li></ul> </td></tr> <tr> <td style="font-size: 95%; color:White; background-color:#33CC00; text-align:center;"><b>Divide and multiply</b> </td></tr> <tr> <td style="font-size: 95%; background-color:#e1ffd6;"> <ul><li><a href="/wiki/Laminin" title="Laminin">Laminin</a></li> <li><a href="/wiki/Biological_determinism" title="Biological determinism">Biological determinism</a></li> <li><a href="/wiki/Lenski_affair" title="Lenski affair">Lenski affair</a></li> <li><a href="/wiki/Suboptimal_design" title="Suboptimal design">Suboptimal design</a></li> <li><a href="/wiki/Jonas_Salk" title="Jonas Salk">Jonas Salk</a></li></ul> </td></tr> <tr> <td style="font-size: 95%; color:White; background-color:#33CC00; text-align:center;"><b>Great Apes</b> </td></tr> <tr> <td style="font-size: 95%; background-color:#e1ffd6;"> <ul><li><a href="/wiki/Linus_Pauling" title="Linus Pauling">Linus Pauling</a></li> <li><a href="/wiki/Nikolai_Vavilov" title="Nikolai Vavilov">Nikolai Vavilov</a></li> <li><a href="/wiki/Pyotr_Kropotkin" title="Pyotr Kropotkin">Pyotr Kropotkin</a></li> <li><a href="/wiki/Charles_Darwin" title="Charles Darwin">Charles Darwin</a></li> <li><a href="/wiki/Akinwumi_Adesina" title="Akinwumi Adesina">Akinwumi Adesina</a></li></ul> <div class="vte plainlinks" style="font-size:smaller; text-align:center;"><a href="/wiki/Template:Biology" title="Template:Biology">v</a> - <a href="/wiki/Template_talk:Biology" title="Template talk:Biology">t</a> - <a rel="nofollow" class="external text" href="https://rationalwiki.org/w/index.php?title=Template:Biology&action=edit">e</a></div> </td></tr></tbody></table> <table style="margin: auto; border-collapse:collapse; border-style:none; background-color:transparent;" class="cquote"> <tbody><tr> <td><div style="padding:4px 50px;position:relative;"><span style="position:absolute;left:10px;top:-6px;z-index:1;font-family:'Times New Roman',serif;font-weight:bold;color:#B2B7F2;font-size:36px">“</span><span style="position:absolute;right:10px;bottom:-20px;z-index:1;font-family:'Times New Roman',serif;font-weight:bold;color:#B2B7F2;font-size:36px">”</span>Brain and brain! <i>What is brain?!</i></div> </td></tr> </tbody></table> <p>The <b>brain</b> is the chunk of fat that sits at the terminus of the central nervous system and helps coordinate sensory input, motor activity, and behavior. Most animals have something similar to a brain, though the level of complexity differs greatly across taxa. We all have a brain (well, <a href="https://en.wikipedia.org/wiki/anencephaly" class="extiw" title="wp:anencephaly" rel="nofollow"><span style="color:#477979 !important;" title="Wikipedia: anencephaly">most of us anyway</span></a>),<sup><img alt="" src="https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/12px-Wikipedia%27s_W.svg.png" decoding="async" width="12" height="12" srcset="https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/18px-Wikipedia%27s_W.svg.png 1.5x, https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/24px-Wikipedia%27s_W.svg.png 2x" data-file-width="128" data-file-height="128" /></sup> but only some of us think with it.<sup>[<i>citation NOT needed</i>]</sup> </p><p>In humans, the brain is involved in thought, emotion, desire, action, choice, memories, and sensory processing. Other parts of the nervous system can do some basic preprocessing and all parts are needed, but the brain is in charge. Many people believe that the mind is not totally reducible to the brain.<sup id="cite_ref-1" class="reference"><a href="#cite_note-1">[note 1]</a></sup> This idea is rejected by most neurologists as unscientific and unnecessary to explain the function of the <a href="/wiki/Mind" title="Mind">mind</a>. </p> <div id="toc" class="toc" role="navigation" aria-labelledby="mw-toc-heading"><input type="checkbox" role="button" id="toctogglecheckbox" class="toctogglecheckbox" style="display:none" /><div class="toctitle" lang="en" dir="ltr"><h2 id="mw-toc-heading">Contents</h2><span class="toctogglespan"><label class="toctogglelabel" for="toctogglecheckbox"></label></span></div> <ul> <li class="toclevel-1 tocsection-1"><a href="#Basic_anatomy_of_the_human_brain"><span class="tocnumber">1</span> <span class="toctext">Basic anatomy of the human brain</span></a></li> <li class="toclevel-1 tocsection-2"><a href="#Brain_size_and_intelligence"><span class="tocnumber">2</span> <span class="toctext">Brain size and intelligence</span></a></li> <li class="toclevel-1 tocsection-3"><a href="#Evolution_of_the_human_brain"><span class="tocnumber">3</span> <span class="toctext">Evolution of the human brain</span></a></li> <li class="toclevel-1 tocsection-4"><a href="#Unused_part_of_the_brain"><span class="tocnumber">4</span> <span class="toctext">Unused part of the brain</span></a></li> <li class="toclevel-1 tocsection-5"><a href="#Who.27s_in_control_here.3F"><span class="tocnumber">5</span> <span class="toctext">Who's in control here?</span></a></li> <li class="toclevel-1 tocsection-6"><a href="#The_brain_and_modern_toys"><span class="tocnumber">6</span> <span class="toctext">The brain and modern toys</span></a> <ul> <li class="toclevel-2 tocsection-7"><a href="#MRI"><span class="tocnumber">6.1</span> <span class="toctext">MRI</span></a></li> <li class="toclevel-2 tocsection-8"><a href="#fMRI"><span class="tocnumber">6.2</span> <span class="toctext">fMRI</span></a></li> <li class="toclevel-2 tocsection-9"><a href="#TMS"><span class="tocnumber">6.3</span> <span class="toctext">TMS</span></a></li> </ul> </li> <li class="toclevel-1 tocsection-10"><a href="#Tasty_brains"><span class="tocnumber">7</span> <span class="toctext">Tasty brains</span></a></li> <li class="toclevel-1 tocsection-11"><a href="#Neuroscience"><span class="tocnumber">8</span> <span class="toctext">Neuroscience</span></a> <ul> <li class="toclevel-2 tocsection-12"><a href="#Folk_neuroscience"><span class="tocnumber">8.1</span> <span class="toctext">Folk neuroscience</span></a></li> <li class="toclevel-2 tocsection-13"><a href="#Common_handwaving"><span class="tocnumber">8.2</span> <span class="toctext">Common handwaving</span></a></li> </ul> </li> <li class="toclevel-1 tocsection-14"><a href="#See_also"><span class="tocnumber">9</span> <span class="toctext">See also</span></a> <ul> <li class="toclevel-2 tocsection-15"><a href="#The_topics_below_are_not_accredited_science."><span class="tocnumber">9.1</span> <span class="toctext">The topics below are not accredited science.</span></a></li> </ul> </li> <li class="toclevel-1 tocsection-16"><a href="#External_links"><span class="tocnumber">10</span> <span class="toctext">External links</span></a></li> <li class="toclevel-1 tocsection-17"><a href="#Notes"><span class="tocnumber">11</span> <span class="toctext">Notes</span></a></li> <li class="toclevel-1 tocsection-18"><a href="#References"><span class="tocnumber">12</span> <span class="toctext">References</span></a></li> </ul> </div> <h2><span class="mw-headline" id="Basic_anatomy_of_the_human_brain">Basic anatomy of the human brain</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Brain&action=edit&section=1" title="Edit section: Basic anatomy of the human brain">edit</a><span class="mw-editsection-bracket">]</span></span></h2> <div class="thumb tleft"><div class="thumbinner" style="width:202px;"><a href="/wiki/File:1543,_Andreas_Vesalius%27_Fabrica,_Base_Of_The_Brain.jpg" class="image"><img alt="" src="https://upload.wikimedia.org/wikipedia/commons/thumb/3/3a/1543%2C_Andreas_Vesalius%27_Fabrica%2C_Base_Of_The_Brain.jpg/200px-1543%2C_Andreas_Vesalius%27_Fabrica%2C_Base_Of_The_Brain.jpg" decoding="async" width="200" height="224" class="thumbimage" srcset="https://upload.wikimedia.org/wikipedia/commons/thumb/3/3a/1543%2C_Andreas_Vesalius%27_Fabrica%2C_Base_Of_The_Brain.jpg/300px-1543%2C_Andreas_Vesalius%27_Fabrica%2C_Base_Of_The_Brain.jpg 1.5x, https://upload.wikimedia.org/wikipedia/commons/thumb/3/3a/1543%2C_Andreas_Vesalius%27_Fabrica%2C_Base_Of_The_Brain.jpg/400px-1543%2C_Andreas_Vesalius%27_Fabrica%2C_Base_Of_The_Brain.jpg 2x" data-file-width="1202" data-file-height="1346" /></a> <div class="thumbcaption"><div class="magnify"><a href="/wiki/File:1543,_Andreas_Vesalius%27_Fabrica,_Base_Of_The_Brain.jpg" class="internal" title="Enlarge"></a></div>The base of the human brain as illustrated in 1543.</div></div></div> <p>The first part to understanding anatomy is to understand directional terms. There are three axes: top to bottom, front to back, and left to right of center. The top is referred to as dorsal, the bottom as ventral(sometimes superior and inferior as well). The front is anterior and the back is posterior, while those areas in the center of the brain are medial and those moving to the left or right side are lateral. </p><p>The human brain is anatomically referenced based on several distinct and universal features. The most notable is the medial longitudinal fissure, which is a wide gap that separates the brain into two hemispheres (right and left). Moving from the middle of the fissure down the sides of the brain is the central sulcus. From the side view of the brain, another sulcus (or gap) can be seen just below the central sulcus, running from the bottom front to about halfway back. This is the superior temporal sulcus. </p><p>The brain has two major divisions, cortical and sub-cortical. The cortical structures are on the outside of the brain and are the folds of gray and white matter that most people picture as being the brain. Below that are the sub-cortical structures. </p><p>There are four major lobes in the cortex each playing a dominant role in different functions. The frontal lobe is the whole section of the brain that is anterior to the central sulcus and ventral to the superior temporal sulcus. The parietal lobe is posterior to the central sulcus and ventral to the superior temporal sulcus. The temporal lobe is dorsal to the superior temporal sulcus. Finally, there is the occipital lobe, which is at the most posterior region of the cortex. </p><p>The frontal lobe is associated with executive function, logical thought, planning, motivation, and many of the “higher order” brain functions. The parietal lobe contains the sensory cortex and is responsible for a large portion of sensory integration. The temporal lobe is associated with memory and learning. The occipital lobe is the visual processing center of the brain. </p><p>At cellular level, <a href="https://en.wikipedia.org/wiki/neuron" class="extiw" title="wp:neuron" rel="nofollow"><span style="color:#477979 !important;" title="Wikipedia: neuron">neuron</span>s</a><sup><img alt="" src="https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/12px-Wikipedia%27s_W.svg.png" decoding="async" width="12" height="12" srcset="https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/18px-Wikipedia%27s_W.svg.png 1.5x, https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/24px-Wikipedia%27s_W.svg.png 2x" data-file-width="128" data-file-height="128" /></sup> are the primary cells that form the brain and the rest of the nervous system, with a number that in humans is 10-20 billion in the former plus another 55-70 billion in the <a href="https://en.wikipedia.org/wiki/cerebellum" class="extiw" title="wp:cerebellum" rel="nofollow"><span style="color:#477979 !important;" title="Wikipedia: cerebellum">cerebellum</span></a>.<sup><img alt="" src="https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/12px-Wikipedia%27s_W.svg.png" decoding="async" width="12" height="12" srcset="https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/18px-Wikipedia%27s_W.svg.png 1.5x, https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/24px-Wikipedia%27s_W.svg.png 2x" data-file-width="128" data-file-height="128" /></sup> They are accompanied by similar numbers of <a href="https://en.wikipedia.org/wiki/Glia" class="extiw" title="wp:Glia" rel="nofollow"><span style="color:#477979 !important;" title="Wikipedia: Glia">support cells</span></a>,<sup><img alt="" src="https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/12px-Wikipedia%27s_W.svg.png" decoding="async" width="12" height="12" srcset="https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/18px-Wikipedia%27s_W.svg.png 1.5x, https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/24px-Wikipedia%27s_W.svg.png 2x" data-file-width="128" data-file-height="128" /></sup> whose functions include structural and metabolic support, insulation of neurons producing myelin sheaths, immune response, and tissue maintenance among others. </p> <h2><span class="mw-headline" id="Brain_size_and_intelligence">Brain size and intelligence</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Brain&action=edit&section=2" title="Edit section: Brain size and intelligence">edit</a><span class="mw-editsection-bracket">]</span></span></h2> <div class="thumb tright"><div class="thumbinner" style="width:252px;"><a href="/wiki/File:Chimp_Brain_in_a_jar.jpg" class="image"><img alt="" src="https://upload.wikimedia.org/wikipedia/commons/thumb/1/14/Chimp_Brain_in_a_jar.jpg/250px-Chimp_Brain_in_a_jar.jpg" decoding="async" width="250" height="315" class="thumbimage" srcset="https://upload.wikimedia.org/wikipedia/commons/thumb/1/14/Chimp_Brain_in_a_jar.jpg/375px-Chimp_Brain_in_a_jar.jpg 1.5x, https://upload.wikimedia.org/wikipedia/commons/thumb/1/14/Chimp_Brain_in_a_jar.jpg/500px-Chimp_Brain_in_a_jar.jpg 2x" data-file-width="2540" data-file-height="3200" /></a> <div class="thumbcaption"><div class="magnify"><a href="/wiki/File:Chimp_Brain_in_a_jar.jpg" class="internal" title="Enlarge"></a></div>The brain of some unfortunate chimpanzee.</div></div></div> <p><a href="/wiki/Carl_Sagan" title="Carl Sagan">Carl Sagan</a> suggested that the advent of Caesarean sections and <i>in vitro</i> fertilization may permit humans to evolve <a href="https://en.wikipedia.org/wiki/Brain_size#Cranial_capacity" class="extiw" title="wp:Brain size" rel="nofollow"><span style="color:#477979 !important;" title="Wikipedia: Brain size#Cranial capacity">larger heads</span></a>,<sup><img alt="" src="https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/12px-Wikipedia%27s_W.svg.png" decoding="async" width="12" height="12" srcset="https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/18px-Wikipedia%27s_W.svg.png 1.5x, https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/24px-Wikipedia%27s_W.svg.png 2x" data-file-width="128" data-file-height="128" /></sup> resulting in improvements via natural selection in the heritable component of human intelligence.<sup id="cite_ref-2" class="reference"><a href="#cite_note-2">[1]</a></sup> However, neurological functions are determined more by the organization of the brain rather than the volume; Neanderthal cranial capacity for females was 1300 cm<sup>3</sup> and 1600 cm<sup>3</sup> for males,<sup id="cite_ref-3" class="reference"><a href="#cite_note-3">[2]</a></sup> while among modern <i>Homo sapiens</i>, northern populations have a 20% larger visual cortex than those in the southern latitude populations, and this potentially explains the population differences in brain size (and roughly cranial capacity).<sup id="cite_ref-4" class="reference"><a href="#cite_note-4">[3]</a></sup><sup id="cite_ref-5" class="reference"><a href="#cite_note-5">[4]</a></sup> Either way, gigantic heads remain a long-standing cliché for abnormally intelligent characters in <a href="/wiki/Science_fiction" title="Science fiction">science fiction</a>. Fan et al. found a more complex pattern, noting: "Crania of African ancestry tended to have a narrower cranial base, and those of Northern European ancestry had elongated occipital and frontal regions. Crania of East Asian ancestry had a high cranial vault, and crania of Native American ancestry were flatter."<sup id="cite_ref-6" class="reference"><a href="#cite_note-6">[5]</a></sup> </p> <h2><span class="mw-headline" id="Evolution_of_the_human_brain">Evolution of the human brain</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Brain&action=edit&section=3" title="Edit section: Evolution of the human brain">edit</a><span class="mw-editsection-bracket">]</span></span></h2> <p>The human brain has several unique features, most notably a massively expanded frontal lobe and significant anatomical specification throughout the frontal lobe tissue. Other areas linked to language processing are also highly developed. This massive expansion of the frontal lobe does not seem to coincide with any immediate changes in survival skills for the human species. Many early <a href="/wiki/Hypothesis" title="Hypothesis">hypotheses</a> for the <a href="/wiki/Evolution" title="Evolution">evolutionary</a> pressures leading to this expansion (such as hunting, tool making, or language development) did not coincide temporally with when the expansion took place. Most current hypotheses focus on this expansion as being driven by social navigation or even sexual selection. </p> <h2><span class="mw-headline" id="Unused_part_of_the_brain">Unused part of the brain</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Brain&action=edit&section=4" title="Edit section: Unused part of the brain">edit</a><span class="mw-editsection-bracket">]</span></span></h2> <p>A lot of woo (and science fiction) centers around the idea that 90% of the brain is unused, and we could perform amazing feats if we could tap into it. Sadly, as awesome as that would be, we're pretty much using all we've got.<sup id="cite_ref-7" class="reference"><a href="#cite_note-7">[6]</a></sup> One simple refutation of the myth is that if it were true, we could lose large chunks of brain without impairment, which is most certainly not the case. Not to mention that evolution would select against having this unused 90% sitting around, eating up oxygen and nutrients and making childbirth that much more painful and dangerous, unless there was a tangible benefit rather than a potential one. Many of these ideas specifically center on using 100% of your brain <i>all at once</i> to make these superhuman feats attainable. People who actually have some knowledge about this subject will recognize that some people really do this already, and that the medical term for it is a generalized tonic-clonic seizure (also known as a grand mal seizure); this is clearly not a higher form of thought, and is in fact a highly dangerous and sometimes deadly occurrence. </p> <h2><span id="Who's_in_control_here?"></span><span class="mw-headline" id="Who.27s_in_control_here.3F">Who's in control here?</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Brain&action=edit&section=5" title="Edit section: Who's in control here?">edit</a><span class="mw-editsection-bracket">]</span></span></h2> <p>The gut <a href="/wiki/Bacteria#Microbiomes" title="Bacteria">microbiome</a> has an effect on <a class="mw-selflink selflink">brain</a> functioning, including various social, emotional, and anxiety-like behaviours.<sup id="cite_ref-8" class="reference"><a href="#cite_note-8">[7]</a></sup> </p> <h2><span class="mw-headline" id="The_brain_and_modern_toys">The brain and modern toys</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Brain&action=edit&section=6" title="Edit section: The brain and modern toys">edit</a><span class="mw-editsection-bracket">]</span></span></h2> <div class="thumb tright"><div class="thumbinner" style="width:302px;"><a href="/wiki/File:Liberal_Brain.jpg" class="image"><img alt="" src="/w/images/thumb/f/fb/Liberal_Brain.jpg/300px-Liberal_Brain.jpg" decoding="async" width="300" height="237" class="thumbimage" srcset="/w/images/thumb/f/fb/Liberal_Brain.jpg/450px-Liberal_Brain.jpg 1.5x, /w/images/f/fb/Liberal_Brain.jpg 2x" data-file-width="550" data-file-height="434" /></a> <div class="thumbcaption"><div class="magnify"><a href="/wiki/File:Liberal_Brain.jpg" class="internal" title="Enlarge"></a></div>Real brain scans, unfortunately, aren't this simple or conclusive. We can conclude, however, that this brain is made out of <a href="/wiki/Straw_man" title="Straw man">straw</a>.</div></div></div> <p>A new era in understanding how the brain creates thought has emerged with the development of several new toys. We now have the ability to non-invasively image the anatomy of the brain and functional activation of brain areas, measure cell firing rates, and even change the firing patterns of brain areas. Sadly, we still haven't figured out how to read minds completely without technology. </p> <h3><span class="mw-headline" id="MRI">MRI</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Brain&action=edit&section=7" title="Edit section: MRI">edit</a><span class="mw-editsection-bracket">]</span></span></h3> <p><a href="/wiki/MRI" title="MRI">Magnetic Resonance Imaging</a> uses a strong magnetic field to align the magnetic fields of hydrogen nuclei in the body. Applying radio-frequency radiation distorts this polarisation, and as the nuclei return to their original lowest energy state they emit further radio waves that can be translated into an image. Different molecules emit different energy patterns and so different things can be imaged from the same machine. </p><p>The most common molecule to be imaged is water and fat, as these are the most abundant in the body, providing good, clear images of the anatomy. </p> <h3><span class="mw-headline" id="fMRI">fMRI</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Brain&action=edit&section=8" title="Edit section: fMRI">edit</a><span class="mw-editsection-bracket">]</span></span></h3> <p>Functional Magnetic Resonance Imaging works the same way as any MRI, but instead of water the machine is calibrated to measure blood. It is theorized that brain areas that are undergoing increased activation will also have a corresponding increase in metabolic requirements. The need to provide oxygen to these areas will increase the blood flow. Thus the fMRI measures the blood-oxygen-level dependent (BOLD) signal. </p><p>The BOLD signal is often superimposed on an anatomical MRI. This allows figuring out which areas of the brain seemed to be activated at a particular time. </p> <h3><span class="mw-headline" id="TMS">TMS</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Brain&action=edit&section=9" title="Edit section: TMS">edit</a><span class="mw-editsection-bracket">]</span></span></h3> <p>Transcranial Magnetic Stimulation is the “black art” of <a href="/wiki/Neuroscience" class="mw-redirect" title="Neuroscience">neuroscience</a>. Essentially, a large coil has an electrical field pulsed through it, which (supposedly) can be used to temporarily change the firing patterns of neurons in the brain. It is not clear whether the TMS acts to excite or inhibit brain activation (or even do both). Effects from the TMS can last as long as 12-24 hours after application or as short as a few minutes. </p> <h2><span class="mw-headline" id="Tasty_brains">Tasty brains</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Brain&action=edit&section=10" title="Edit section: Tasty brains">edit</a><span class="mw-editsection-bracket">]</span></span></h2> <div class="thumb tright"><div class="thumbinner" style="width:252px;"><a href="/wiki/File:Zombie.jpg" class="image"><img alt="" src="/w/images/thumb/e/e7/Zombie.jpg/250px-Zombie.jpg" decoding="async" width="250" height="255" class="thumbimage" srcset="/w/images/thumb/e/e7/Zombie.jpg/375px-Zombie.jpg 1.5x, /w/images/thumb/e/e7/Zombie.jpg/500px-Zombie.jpg 2x" data-file-width="588" data-file-height="600" /></a> <div class="thumbcaption"><div class="magnify"><a href="/wiki/File:Zombie.jpg" class="internal" title="Enlarge"></a></div>Braaaaaaiiiins!!!! Brahhhhiaaaannnnsssss.... Mrsssuuurrrrrrhhhhh.... Braaiaiaaaannnssssz....</div></div></div> <p>There's good eating on a brain. While it is socially unacceptable to eat a <a href="/wiki/Human" title="Human">human</a> brain — unless you are Hannibal Lecter, a <a href="/wiki/Conservapedia" title="Conservapedia">Conservapedian</a> (providing it's your own brain), or a <a href="/wiki/Zombie" class="mw-redirect" title="Zombie">zombie</a><sup id="cite_ref-9" class="reference"><a href="#cite_note-9">[note 2]</a></sup> — the brain of a cow, pig, <a href="/wiki/Goat" title="Goat">goat</a> or, in some exotic locations, a monkey, can make a nutritious meal, although it's relatively tasteless by itself (to the extent they have any flavor on their own, it's vaguely like scrambled eggs with a much more mushy texture) and is rather high (as in 1000%—1500% of recommended daily intake per serving, depending on the animal) in cholesterol. Problematically, ignoring social constraints and eating human brains can cause kuru, a <a href="/wiki/Prion" title="Prion">prion</a> disease similar to <a href="/wiki/Mad_Cow_Disease" class="mw-redirect" title="Mad Cow Disease">Mad Cow Disease</a>, while eating the brains of cows and <a href="/wiki/Sheep" title="Sheep">sheep</a>, and possibly also <a href="/wiki/Pig" class="mw-redirect" title="Pig">pigs</a> etc. can cause actual Mad Cow Disease, or just cause heart attacks. </p><p>The immense similarity in reactions between <a href="/wiki/Creationists" class="mw-redirect" title="Creationists">creationists</a> and zombies is, frankly, appalling, and not worth repeating.<sup id="cite_ref-10" class="reference"><a href="#cite_note-10">[note 3]</a></sup> </p> <h2><span class="mw-headline" id="Neuroscience">Neuroscience</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Brain&action=edit&section=11" title="Edit section: Neuroscience">edit</a><span class="mw-editsection-bracket">]</span></span></h2> <p>Neuroscience is the scientific study of the nervous system. </p><p>Throughout history, changes in behaviour have been noted in people who receive injuries to the brain, but in recent decades technology has allowed for scientists to actually study why this is. </p><p>Learning how the brain develops and functions can lead to treatments and preventions of neurological disorders such as Parkinson's and Alzheimer's. </p><p>Such treatments may be possible through <a href="/wiki/Stem_cell_research" title="Stem cell research">stem cell research</a>, which is controversial when it utilizes embryos. </p> <h3><span class="mw-headline" id="Folk_neuroscience">Folk neuroscience</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Brain&action=edit&section=12" title="Edit section: Folk neuroscience">edit</a><span class="mw-editsection-bracket">]</span></span></h3> <p>Even folksy generalizations about neuroscience are useful to the average person because: (1) the brain and nervous system are amazingly complex; (2) research is on-going; (3) findings by investigations have enormous consequences in terms of understanding ourselves, human culture, and the evolution of "<a href="/wiki/Reason" title="Reason">reason</a>" and "<a href="/wiki/Religion" title="Religion">religion</a>"; (4) we never learned this stuff in high school, and (5) the learning curve needs to start somewhere. But when the learning curve stops, the <a href="/wiki/Woo" title="Woo">woo</a> begins. Topics with enormous potential for enlightenment and mischief are the following: </p> <ul><li><a href="/wiki/Human_nature" title="Human nature">Human nature</a> and its anthropological cousin, <a href="https://en.wikipedia.org/wiki/Cultural_universal" class="extiw" title="wp:Cultural universal" rel="nofollow"><span style="color:#477979 !important;" title="Wikipedia: Cultural universal">cultural universals</span></a><sup><img alt="" src="https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/12px-Wikipedia%27s_W.svg.png" decoding="async" width="12" height="12" srcset="https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/18px-Wikipedia%27s_W.svg.png 1.5x, https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/24px-Wikipedia%27s_W.svg.png 2x" data-file-width="128" data-file-height="128" /></sup></li> <li><a href="/wiki/Hemispheric_dominance" title="Hemispheric dominance">Hemispheric dominance</a> (left-brain, right brain)</li> <li><a href="https://en.wikipedia.org/wiki/Triune_brain" class="extiw" title="wp:Triune brain" rel="nofollow"><span style="color:#477979 !important;" title="Wikipedia: Triune brain">Reptile brain</span></a><sup><img alt="" src="https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/12px-Wikipedia%27s_W.svg.png" decoding="async" width="12" height="12" srcset="https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/18px-Wikipedia%27s_W.svg.png 1.5x, https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/24px-Wikipedia%27s_W.svg.png 2x" data-file-width="128" data-file-height="128" /></sup></li> <li><a href="https://en.wikipedia.org/wiki/Neural_oscillation" class="extiw" title="wp:Neural oscillation" rel="nofollow"><span style="color:#477979 !important;" title="Wikipedia: Neural oscillation">Brain waves</span></a><sup><img alt="" src="https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/12px-Wikipedia%27s_W.svg.png" decoding="async" width="12" height="12" srcset="https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/18px-Wikipedia%27s_W.svg.png 1.5x, https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/24px-Wikipedia%27s_W.svg.png 2x" data-file-width="128" data-file-height="128" /></sup> and <a href="/wiki/Brainwave_woo" title="Brainwave woo">Brainwave woo</a></li></ul> <h3><span class="mw-headline" id="Common_handwaving">Common handwaving</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Brain&action=edit&section=13" title="Edit section: Common handwaving">edit</a><span class="mw-editsection-bracket">]</span></span></h3> <p>It's a relatively common to handwave pseudoscienctific assertions about human nature as being backed by neuroscience: keep an eye out for direct references to actual scientific papers that use observational evidence, whose claims tend not to be quite so grandiose. To see examples, try searching the internet for the phrase "Neuroscience says that". You can find all sorts of generalizations that have no real basis, like: </p> <ul><li>Becoming immune to stress<sup id="cite_ref-11" class="reference"><a href="#cite_note-11">[8]</a></sup><sup id="cite_ref-12" class="reference"><a href="#cite_note-12">[9]</a></sup></li> <li>The right side of the brain that specializes in creativity (See the <a href="/wiki/Hemispheric_dominance" title="Hemispheric dominance">hemispheric dominance</a> article for why this is wrong)</li></ul> <p>Usually, these kinds of claims come from <a href="/wiki/Charlatan" title="Charlatan">someone who's trying to sell you something</a> (and <a href="/wiki/Scam" class="mw-redirect" title="Scam">that something is probably useless</a>). </p> <h2><span class="mw-headline" id="See_also">See also</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Brain&action=edit&section=14" title="Edit section: See also">edit</a><span class="mw-editsection-bracket">]</span></span></h2> <ul><li><a href="/wiki/Mind" title="Mind">Mind</a></li> <li><a href="/wiki/Hemispheric_dominance" title="Hemispheric dominance">Hemispheric dominance</a></li> <li><a href="/wiki/Neuroplasticity" title="Neuroplasticity">Neuroplasticity</a></li> <li><a href="/wiki/Non-materialist_neuroscience" title="Non-materialist neuroscience">Non-materialist neuroscience</a></li> <li><a href="/wiki/Split_brain" title="Split brain">Split brain</a></li></ul> <h3><span class="mw-headline" id="The_topics_below_are_not_accredited_science.">The topics below are not accredited science.</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Brain&action=edit&section=15" title="Edit section: The topics below are not accredited science.">edit</a><span class="mw-editsection-bracket">]</span></span></h3> <ul><li><a href="/wiki/Aura" title="Aura">Aura</a></li> <li><a href="/wiki/Brain_Gym" title="Brain Gym">Brain Gym</a></li> <li><a href="/wiki/Brainwave_woo" title="Brainwave woo">Brainwave woo</a></li> <li><a href="/wiki/Deepak_Chopra" title="Deepak Chopra">Deepak Chopra</a></li> <li><a href="/wiki/Indigo_child" title="Indigo child">Indigo child</a></li> <li><a href="/wiki/Human_Potential_Movement" title="Human Potential Movement">Human Potential Movement</a></li> <li><a href="/wiki/Neurolinguistic_programming" title="Neurolinguistic programming">Neurolinguistic programming</a></li> <li><a href="/wiki/Phrenology" title="Phrenology">Phrenology</a></li> <li><a href="/wiki/Soul" title="Soul">Soul</a></li></ul> <h2><span class="mw-headline" id="External_links">External links</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Brain&action=edit&section=16" title="Edit section: External links">edit</a><span class="mw-editsection-bracket">]</span></span></h2> <ul><li><a rel="nofollow" class="external text" href="http://www.snopes.com/science/stats/10percent.asp">Snopes.com - The Ten Percent Myth</a> - exposing the myth that we supposedly "only use 10% of our brains".</li></ul> <ul><li><a rel="nofollow" class="external text" href="http://www.sfn.org">Society for Neuroscience</a></li></ul> <ul><li><a rel="nofollow" class="external text" href="http://www.bbc.co.uk/programmes/b00fbd26">BBC: In Our Time: Neuroscience</a></li></ul> <h2><span class="mw-headline" id="Notes">Notes</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Brain&action=edit&section=17" title="Edit section: Notes">edit</a><span class="mw-editsection-bracket">]</span></span></h2> <div class="references-small" style="font-size:90%;"> <div class="mw-references-wrap"><ol class="references"> <li id="cite_note-1"><span class="mw-cite-backlink"><a href="#cite_ref-1">↑</a></span> <span class="reference-text">See <a href="/wiki/Dualism" title="Dualism">dualism</a> and <a href="/wiki/Non-materialist_neuroscience" title="Non-materialist neuroscience">non-materialist neuroscience</a>.</span> </li> <li id="cite_note-9"><span class="mw-cite-backlink"><a href="#cite_ref-9">↑</a></span> <span class="reference-text">Well, the last two are the same, really.</span> </li> <li id="cite_note-10"><span class="mw-cite-backlink"><a href="#cite_ref-10">↑</a></span> <span class="reference-text">And yet we have. Several times. I guess it's just that funny.</span> </li> </ol></div></div> <h2><span class="mw-headline" id="References">References</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Brain&action=edit&section=18" title="Edit section: References">edit</a><span class="mw-editsection-bracket">]</span></span></h2> <div class="references-small" style="-moz-column-count:2; -webkit-column-count:2; column-count:2; font-size:80%;"> <div class="mw-references-wrap"><ol class="references"> <li id="cite_note-2"><span class="mw-cite-backlink"><a href="#cite_ref-2">↑</a></span> <span class="reference-text"> Sagan, Carl (1977). The Dragons of Eden. Random House.</span> </li> <li id="cite_note-3"><span class="mw-cite-backlink"><a href="#cite_ref-3">↑</a></span> <span class="reference-text">Stanford, C., Allen, J.S., Anton, S.C., Lovell, N.C. (2009). Biological Anthropology: the Natural History of Humankind. Toronto: Pearson Canada. p. 301</span> </li> <li id="cite_note-4"><span class="mw-cite-backlink"><a href="#cite_ref-4">↑</a></span> <span class="reference-text"> "BBC News - Dark winters 'led to bigger human brains and eyeballs'". BBC News.</span> </li> <li id="cite_note-5"><span class="mw-cite-backlink"><a href="#cite_ref-5">↑</a></span> <span class="reference-text">Alok Jha. "People at darker, higher latitudes evolved bigger eyes and brains". <i>The Guardian</i>.</span> </li> <li id="cite_note-6"><span class="mw-cite-backlink"><a href="#cite_ref-6">↑</a></span> <span class="reference-text"><a rel="nofollow" class="external free" href="https://www.cell.com/current-biology/fulltext/S0960-9822(15)00671-5">https://www.cell.com/current-biology/fulltext/S0960-9822(15)00671-5</a></span> </li> <li id="cite_note-7"><span class="mw-cite-backlink"><a href="#cite_ref-7">↑</a></span> <span class="reference-text"><a rel="nofollow" class="external free" href="http://www.scientificamerican.com/article/do-people-only-use-10-percent-of-their-brains/">http://www.scientificamerican.com/article/do-people-only-use-10-percent-of-their-brains/</a></span> </li> <li id="cite_note-8"><span class="mw-cite-backlink"><a href="#cite_ref-8">↑</a></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://www.nature.com/nrn/journal/v15/n2/full/nrn3669.html">The gut–microbiome–brain connection</a></span> </li> <li id="cite_note-11"><span class="mw-cite-backlink"><a href="#cite_ref-11">↑</a></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://www.inc.com/geoffrey-james/neuroscience-become-immune-to-stress.html">Neuroscience: How to Become Immune to Stress</a>. inc.com, 4 October 2014.</span> </li> <li id="cite_note-12"><span class="mw-cite-backlink"><a href="#cite_ref-12">↑</a></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://www.cell.com/cell/abstract/S0092-8674%2814%2901049-6">Skeletal Muscle PGC-1α1 Modulates Kynurenine Metabolism and Mediates Resilience to Stress-Induced Depression</a>. Cell 159:1, 25 September 2014, p. 33-45.</span> </li> </ol></div></div>    </div></div><div class="printfooter">Retrieved from "<a dir="ltr" href="https://rationalwiki.org/w/index.php?title=Brain&oldid=2689385">https://rationalwiki.org/w/index.php?title=Brain&oldid=2689385</a>"</div> <div id="catlinks" class="catlinks" data-mw="interface"><div id="mw-normal-catlinks" class="mw-normal-catlinks"><a href="/wiki/Special:Categories" title="Special:Categories">Categories</a>: <ul><li><a href="/wiki/Category:Bronze-level_articles" title="Category:Bronze-level articles">Bronze-level articles</a></li><li><a href="/wiki/Category:Biology" title="Category:Biology">Biology</a></li><li><a href="/wiki/Category:Medicine" title="Category:Medicine">Medicine</a></li><li><a href="/wiki/Category:Science" title="Category:Science">Science</a></li><li><a href="/wiki/Category:Anatomy" title="Category:Anatomy">Anatomy</a></li></ul></div><div id="mw-hidden-catlinks" class="mw-hidden-catlinks mw-hidden-cats-hidden">Hidden category: <ul><li><a href="/wiki/Category:Pages_using_DynamicPageList_parser_function" title="Category:Pages using DynamicPageList parser function">Pages using DynamicPageList parser function</a></li></ul></div></div> </div> </div> <div id="mw-navigation"> <h2>Navigation menu</h2> <div id="mw-head">  <nav id="p-personal" class="vector-menu" aria-labelledby="p-personal-label" role="navigation" > <h3 id="p-personal-label"> <span>Personal tools</span> </h3>  <div class="body vector-menu-content">  <ul class="vector-menu-content-list"><li id="pt-anonuserpage">Not logged in</li><li id="pt-anontalk"><a href="/wiki/Special:MyTalk" title="Discussion about edits from this IP address [n]" accesskey="n">Talk</a></li><li id="pt-anoncontribs"><a href="/wiki/Special:MyContributions" title="A list of edits made from this IP address [y]" accesskey="y">Contributions</a></li><li id="pt-createaccount"><a href="/w/index.php?title=Special:CreateAccount&returnto=Brain" title="You are encouraged to create an account and log in; however, it is not mandatory">Create account</a></li><li id="pt-login"><a href="/w/index.php?title=Special:UserLogin&returnto=Brain" title="You are encouraged to log in; however, it is not mandatory [o]" accesskey="o">Log in</a></li></ul> </div> </nav> <div id="left-navigation">  <nav id="p-namespaces" class="vector-menu vector-menu-tabs vectorTabs" aria-labelledby="p-namespaces-label" role="navigation" > <h3 id="p-namespaces-label"> <span>Namespaces</span> </h3>  <div class="body vector-menu-content">  <ul class="vector-menu-content-list"><li id="ca-nstab-main" class="selected"><a href="/wiki/Brain" title="View the content page [c]" accesskey="c">Page</a></li><li id="ca-talk"><a href="/wiki/Talk:Brain" rel="discussion" title="Discussion about the content page [t]" accesskey="t">Talk</a></li></ul> </div> </nav>  <nav id="p-variants" class="vector-menu-empty emptyPortlet vector-menu vector-menu-dropdown vectorMenu" aria-labelledby="p-variants-label" role="navigation" > <input type="checkbox" class="vector-menu-checkbox vectorMenuCheckbox" aria-labelledby="p-variants-label" /> <h3 id="p-variants-label"> <span>Variants</span> </h3>  <div class="body vector-menu-content">  <ul class="menu vector-menu-content-list"></ul> </div> </nav> </div> <div id="right-navigation">  <nav id="p-views" class="vector-menu vector-menu-tabs vectorTabs" aria-labelledby="p-views-label" role="navigation" > <h3 id="p-views-label"> <span>Views</span> </h3>  <div class="body vector-menu-content">  <ul class="vector-menu-content-list"><li id="ca-view" class="collapsible selected"><a href="/wiki/Brain">Read</a></li><li id="ca-edit" class="collapsible"><a href="/w/index.php?title=Brain&action=edit" title="Edit this page [e]" accesskey="e">Edit</a></li><li id="ca-history" class="collapsible"><a href="/w/index.php?title=Brain&action=history" title="Past revisions of this page [h]" accesskey="h">Fossil record</a></li></ul> </div> </nav>  <nav id="p-cactions" class="vector-menu-empty emptyPortlet vector-menu vector-menu-dropdown vectorMenu" aria-labelledby="p-cactions-label" role="navigation" > <input type="checkbox" class="vector-menu-checkbox vectorMenuCheckbox" aria-labelledby="p-cactions-label" /> <h3 id="p-cactions-label"> <span>More</span> </h3>  <div class="body vector-menu-content">  <ul class="menu vector-menu-content-list"></ul> </div> </nav> <div id="p-search" role="search"> <h3 > <label for="searchInput">Search</label> </h3> <form action="/w/index.php" id="searchform"> <div id="simpleSearch"> <input type="search" name="search" placeholder="Search RationalWiki" title="Search RationalWiki [f]" accesskey="f" id="searchInput"/> <input type="hidden" name="title" value="Special:Search"> <input type="submit" name="fulltext" value="Search" title="Search the pages for this text" id="mw-searchButton" class="searchButton mw-fallbackSearchButton"/> <input type="submit" name="go" value="Go" title="Go to a page with this exact name if it exists" id="searchButton" class="searchButton"/> </div> </form> </div> </div> </div> <div id="mw-panel"> <div id="p-logo" role="banner"> <a title="Visit the main page" class="mw-wiki-logo" href="/wiki/Main_Page"></a> </div>  <nav id="p-navigation" class="vector-menu vector-menu-portal portal portal-first" aria-labelledby="p-navigation-label" role="navigation" > <h3 id="p-navigation-label"> <span>Navigation</span> </h3>  <div class="body vector-menu-content">  <ul class="vector-menu-content-list"><li id="n-mainpage-description"><a href="/wiki/Main_Page" title="Visit the main page [z]" accesskey="z">Main page</a></li><li id="n-recentchanges"><a href="/wiki/Special:RecentChanges" title="A list of recent changes in the wiki [r]" accesskey="r">Recent changes</a></li><li id="n-randompage"><a href="/wiki/Special:Random" title="Load a random mainspace article [x]" accesskey="x">Random page</a></li><li id="n-New-pages"><a href="/wiki/Special:NewPages">New pages</a></li><li id="n-All-logs"><a href="/wiki/Special:Log">All logs</a></li><li id="n-help"><a href="/wiki/Help:Contents" title="RTFM">Help</a></li></ul> </div> </nav>  <nav id="p-support" class="vector-menu vector-menu-portal portal" aria-labelledby="p-support-label" role="navigation" > <h3 id="p-support-label"> <span>Support</span> </h3>  <div class="body vector-menu-content">  <ul class="vector-menu-content-list"><li id="n-Donate"><a href="/wiki/RationalWiki:Site_support">Donate</a></li></ul> </div> </nav>  <nav id="p-community" class="vector-menu vector-menu-portal portal" aria-labelledby="p-community-label" role="navigation" > <h3 id="p-community-label"> <span>Community</span> </h3>  <div class="body vector-menu-content">  <ul class="vector-menu-content-list"><li id="n-Saloon-bar"><a href="/wiki/RationalWiki:Saloon_bar">Saloon bar</a></li><li id="n-To-do-list"><a href="/wiki/RationalWiki:To_do_list">To do list</a></li><li id="n-What-is-going-on.3F"><a href="/wiki/WIGO">What is going on?</a></li><li id="n-Best-of-RationalWiki"><a href="/wiki/RationalWiki:Contents">Best of RationalWiki</a></li><li id="n-About-RationalWiki"><a href="/wiki/RationalWiki">About RationalWiki</a></li><li id="n-Technical-support"><a href="/wiki/RationalWiki:Technical_support">Technical support</a></li><li id="n-Mod-noticeboard"><a href="/wiki/RationalWiki_talk:All_things_in_moderation">Mod noticeboard</a></li><li id="n-RMF-noticeboard"><a href="/wiki/RationalWiki_talk:RationalMedia_Foundation">RMF noticeboard</a></li></ul> </div> </nav>  <nav id="p-Social media" class="vector-menu vector-menu-portal portal" aria-labelledby="p-Social media-label" role="navigation" > <h3 id="p-Social media-label"> <span>Social media</span> </h3>  <div class="body vector-menu-content">  <ul class="vector-menu-content-list"><li id="n-Twitter"><a href="https://twitter.com/RationalWiki" rel="nofollow">Twitter</a></li><li id="n-Mastodon"><a href="https://mstdn.social/@rationalwiki" rel="nofollow">Mastodon</a></li><li id="n-Facebook"><a href="https://www.facebook.com/pages/Rationalwiki/226614404019306" rel="nofollow">Facebook</a></li><li id="n-Discord"><a href="/wiki/RationalWiki:Discord">Discord</a></li><li id="n-Reddit"><a href="/wiki/RationalWiki:Reddit">Reddit</a></li></ul> </div> </nav>  <nav id="p-tb" class="vector-menu vector-menu-portal portal" aria-labelledby="p-tb-label" role="navigation" > <h3 id="p-tb-label"> <span>Tools</span> </h3>  <div class="body vector-menu-content">  <ul class="vector-menu-content-list"><li id="t-whatlinkshere"><a href="/wiki/Special:WhatLinksHere/Brain" title="A list of all wiki pages that link here [j]" accesskey="j">What links here</a></li><li id="t-recentchangeslinked"><a href="/wiki/Special:RecentChangesLinked/Brain" rel="nofollow" title="Recent changes in pages linked from this page [k]" accesskey="k">Related changes</a></li><li id="t-specialpages"><a href="/wiki/Special:SpecialPages" title="A list of all special pages [q]" accesskey="q">Special pages</a></li><li id="t-print"><a href="javascript:print();" rel="alternate" title="Printable version of this page [p]" accesskey="p">Printable version</a></li><li id="t-permalink"><a href="/w/index.php?title=Brain&oldid=2689385" title="Permanent link to this revision of the page">Permanent link</a></li><li id="t-info"><a href="/w/index.php?title=Brain&action=info" title="More information about this page">Page information</a></li></ul> </div> </nav>  <nav id="p-lang" class="vector-menu vector-menu-portal portal" aria-labelledby="p-lang-label" role="navigation" > <h3 id="p-lang-label"> <span>In other languages</span> </h3>  <div class="body vector-menu-content">  <ul class="vector-menu-content-list"><li class="interlanguage-link interwiki-ru"><a href="http://ru.rationalwiki.org/wiki/%D0%9C%D0%BE%D0%B7%D0%B3" title="Мозг – русский" lang="ru" hreflang="ru" class="interlanguage-link-target">Русский</a></li></ul> </div> </nav> </div> </div> <footer id="footer" class="mw-footer" role="contentinfo" > <ul id="footer-info" > <li id="footer-info-lastmod"> This page was last edited on 24 October 2024, at 00:41.</li> <li id="footer-info-copyright">Unless explicitly noted otherwise, all content licensed as indicated by <a name="Copyright" href="//rationalwiki.org/wiki/RationalWiki:Copyrights">RationalWiki:Copyrights</a>. <br> For concerns on copyright infringement please see: <a name="Copyright infringement" href="//rationalwiki.org/wiki/RationalWiki:Copyright_violations">RationalWiki:Copyright violations</a></li> </ul> <ul id="footer-places" > <li id="footer-places-privacy"><a href="/wiki/RationalWiki:Privacy_policy" title="RationalWiki:Privacy policy">Privacy policy</a></li> <li id="footer-places-about"><a href="/wiki/RationalWiki:About" class="mw-redirect" title="RationalWiki:About">About RationalWiki</a></li> <li id="footer-places-disclaimer"><a href="/wiki/RationalWiki:General_disclaimer" title="RationalWiki:General disclaimer">Disclaimers</a></li> </ul> <ul id="footer-icons" class="noprint"> <li id="footer-copyrightico"><a href="https://creativecommons.org/licenses/by-sa/3.0/"><img src="/w/88x31.png" alt="CC-BY-SA 3.0, or any later version" width="88" height="31" loading="lazy"/></a></li> <li id="footer-poweredbyico"><a href="https://www.mediawiki.org/"><img src="/w/resources/assets/poweredby_mediawiki_88x31.png" alt="Powered by MediaWiki" srcset="/w/resources/assets/poweredby_mediawiki_132x47.png 1.5x, /w/resources/assets/poweredby_mediawiki_176x62.png 2x" width="88" height="31" loading="lazy"/></a></li> </ul> <div style="clear: both;"></div> </footer> <script>(RLQ=window.RLQ||[]).push(function(){mw.config.set({"wgPageParseReport":{"limitreport":{"cputime":"0.330","walltime":"1.048","ppvisitednodes":{"value":781,"limit":1000000},"postexpandincludesize":{"value":8429,"limit":2097152},"templateargumentsize":{"value":1857,"limit":2097152},"expansiondepth":{"value":10,"limit":40},"expensivefunctioncount":{"value":0,"limit":100},"unstrip-depth":{"value":0,"limit":20},"unstrip-size":{"value":4292,"limit":5000000},"timingprofile":["100.00% 57.622 1 -total"," 52.25% 30.110 1 Template:Biology"," 48.17% 27.754 1 Template:Navsidebar"," 39.77% 22.914 2 Template:Navsidebar2"," 35.94% 20.710 2 Template:Randomarticles"," 12.24% 7.053 2 Template:Reflist"," 9.55% 5.503 1 Template:Bronze"," 6.86% 3.951 1 Template:Fact"," 5.32% 3.064 8 Template:Wpl"," 3.50% 2.015 1 Template:Cquote"]},"cachereport":{"origin":"apache5","timestamp":"20250323045335","ttl":86400,"transientcontent":false}}});mw.config.set({"wgBackendResponseTime":51,"wgHostname":"apache5"});});</script></body></html>