{"id":728,"date":"2023-03-10T18:01:52","date_gmt":"2023-03-10T18:01:52","guid":{"rendered":"https:\/\/content.one.lumenlearning.com\/introductiontopsychology\/chapter\/the-biology-of-emotions\/"},"modified":"2026-01-15T18:29:43","modified_gmt":"2026-01-15T18:29:43","slug":"the-biology-of-emotions","status":"publish","type":"chapter","link":"https:\/\/content.one.lumenlearning.com\/introductiontopsychology\/chapter\/the-biology-of-emotions\/","title":{"raw":"Emotion: Learn It 3\u2014The Biology of Emotions","rendered":"Emotion: Learn It 3\u2014The Biology of Emotions"},"content":{"raw":"<h2>\u00a0The Biology of Emotions<\/h2>\r\n<section class=\"textbox recall\">Earlier, you learned about the limbic system, which is an area of the brain involved in emotion and memory (Figure 1). The limbic system includes the hypothalamus, thalamus, amygdala, and the hippocampus. <a href=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/855\/2016\/11\/03231922\/097c83b04dc3fee269b52da8700857ec7b42ec62.jpeg\"><img class=\" wp-image-6914 aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/855\/2016\/11\/03231922\/097c83b04dc3fee269b52da8700857ec7b42ec62.jpeg\" alt=\"An illustration of the brain labels the locations of the \u201cthalamus,\u201d \u201chypothalamus,\u201d \u201camygdala,\u201d and \u201chippocampus.\u201d\" width=\"390\" height=\"327\" \/><\/a><strong>Figure 1<\/strong>. The limbic system, which includes the hypothalamus, thalamus, amygdala, and the hippocampus, is involved in mediating emotional response and memory.<\/section>\r\n<p>Each structure of the limbic system plays a distinct role in emotion:<\/p>\r\n<ul>\r\n\t<li>The hypothalamus plays a role in the activation of the sympathetic nervous system that is a part of any given emotional reaction.<\/li>\r\n\t<li>The thalamus serves as a sensory relay center whose neurons project to both the amygdala and the higher cortical regions for further processing.<\/li>\r\n\t<li>The amygdala plays a role in processing emotional information and sending that information on to cortical structures (Fossati, 2012).<\/li>\r\n\t<li>The hippocampus integrates emotional experiences with cognition (Femen\u00eda, G\u00f3mez-Gal\u00e1n, Lindskog, &amp; Magara, 2012).<\/li>\r\n<\/ul>\r\n<p>Let's take a closer look at the amygdala and the hippocampus and their roles in emotion.<\/p>\r\n<section class=\"textbox keyTakeaway\">\r\n<h3>structure and function of the amygdala<\/h3>\r\n<p>The <strong>amygdala<\/strong> has received a great deal of attention from researchers interested in understanding the biological basis for emotions, especially the emotions of fear and anxiety (Blackford &amp; Pine, 2012; Goosens &amp; Maren, 2002; Maren, Phan, &amp; Liberzon, 2013). The amygdala is composed of various subnuclei (neural subcomponents), including the basolateral complex and the central nucleus.<br \/>\r\n<br \/>\r\n<\/p>\r\n<p>The <strong>basolateral complex<\/strong> has dense connections with a variety of sensory areas of the brain. It is critical for classical conditioning and for attaching emotional value to learning processes and memory.<br \/>\r\n<br \/>\r\n<\/p>\r\n<p>The <strong>central nucleus<\/strong> plays a role in attention, and it has connections with the hypothalamus and various brainstem areas to regulate the autonomic nervous and endocrine systems\u2019 activity (Pessoa, 2010).<\/p>\r\n\r\n[caption id=\"attachment_6917\" align=\"aligncenter\" width=\"394\"]<a href=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/855\/2016\/11\/03232140\/79bfd30ce14938bbbf36af8f5be3f283b4fc5cba.jpeg\"><img class=\" wp-image-6917\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/855\/2016\/11\/03232140\/79bfd30ce14938bbbf36af8f5be3f283b4fc5cba.jpeg\" alt=\"An illustration of the brain labels the locations of the \u201cbasolateral complex\u201d and \u201ccentral nucleus\u201d within the \u201camygdala.\u201d\" width=\"394\" height=\"400\" \/><\/a> <strong>Figure 2<\/strong>. The anatomy of the basolateral complex and central nucleus of the amygdala are illustrated in this diagram.[\/caption]\r\n<\/section>\r\n<section class=\"textbox example\">\r\n<h3><b>A story from animal research: context matters<\/b><\/h3>\r\n<p class=\"p3\">One striking set of studies shows that the amygdala\u2019s role in learning fear can depend heavily on <span class=\"s2\">context<\/span>.<\/p>\r\n<p class=\"p3\">Researchers found that rat pups who experienced an odor paired with a mild shock <span class=\"s2\">without their mother present<\/span> showed increased amygdala activation and later avoided that odor\u2014suggesting they learned fear.<\/p>\r\n<p class=\"p3\">But when the <span class=\"s2\">mother was present<\/span>, the pups actually showed a <span class=\"s2\">preference<\/span> for the odor cue, even though it had been paired with a shock. In that condition, the amygdala did <i>not<\/i> show the same increase in activation. In other words, the mother\u2019s presence changed how the pups\u2019 brains responded\u2014and what they learned (Moriceau &amp; Sullivan, 2006).<\/p>\r\n<\/section>\r\n<section data-depth=\"2\">\r\n<h3><b>Early experience and later emotional patterns<\/b><\/h3>\r\n<p class=\"p3\">Related work suggests that adverse early experiences can alter amygdala functioning in ways that shape later behavior. In one study, rat pups exposed to stressful or abusive-like conditions early in life later showed more \u201cdepressive-like\u201d behavior during adolescence, along with increased amygdala activation (Raineki et al., 2012).<\/p>\r\n<p class=\"p3\">While we should be cautious about directly translating rat findings to humans, this research supports a broader point: early experiences can influence how brain systems involved in threat and emotion develop over time.<\/p>\r\n<h3><b>Links to human mood and anxiety disorders<\/b><\/h3>\r\n<p class=\"p3\">Human research also finds associations between amygdala structure\/function and disorders involving mood and anxiety. Differences in amygdala activity have been observed in adolescents who are at risk for\u2014or diagnosed with\u2014certain anxiety or mood disorders. Some researchers have also explored whether patterns of amygdala activation could help distinguish between conditions such as bipolar disorder and major depressive disorder (though this remains an area of ongoing research).<\/p>\r\n<\/section>\r\n<section data-depth=\"2\">\r\n<h3>Hippocampus<\/h3>\r\n<p class=\"p1\">The <span class=\"s1\"><b>hippocampus<\/b><\/span> is also important in emotional processing, especially because it supports <span class=\"s1\"><b>memory and context<\/b><\/span>. That context matters for emotion: it helps your brain answer questions like, \u201cIs this situation safe?\u201d or \u201cHave I been here before?\u201d<\/p>\r\n<p class=\"p1\">Research links hippocampal structure and function to several mood and anxiety disorders. For example, studies of people with <span class=\"s1\"><b>posttraumatic stress disorder (PTSD)<\/b><\/span> often find reduced volume in parts of the hippocampus. Some researchers suggest these patterns may relate to changes in neurogenesis and dendritic branching (the growth of new neurons and new neural connections).<\/p>\r\n<p class=\"p1\">It\u2019s important to note that many of these studies are correlational, so they cannot prove cause and effect. However, some work suggests that after treatment (including medication and\/or cognitive-behavioral therapy), people with PTSD may show symptom improvement alongside changes in hippocampal functioning and, in some cases, volume measures.<\/p>\r\n<section class=\"textbox tryIt\">[ohm2_question height=\"350\"]4415[\/ohm2_question]<\/section>\r\n<\/section>","rendered":"<h2>\u00a0The Biology of Emotions<\/h2>\n<section class=\"textbox recall\">Earlier, you learned about the limbic system, which is an area of the brain involved in emotion and memory (Figure 1). The limbic system includes the hypothalamus, thalamus, amygdala, and the hippocampus. <a href=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/855\/2016\/11\/03231922\/097c83b04dc3fee269b52da8700857ec7b42ec62.jpeg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-6914 aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/855\/2016\/11\/03231922\/097c83b04dc3fee269b52da8700857ec7b42ec62.jpeg\" alt=\"An illustration of the brain labels the locations of the \u201cthalamus,\u201d \u201chypothalamus,\u201d \u201camygdala,\u201d and \u201chippocampus.\u201d\" width=\"390\" height=\"327\" \/><\/a><strong>Figure 1<\/strong>. The limbic system, which includes the hypothalamus, thalamus, amygdala, and the hippocampus, is involved in mediating emotional response and memory.<\/section>\n<p>Each structure of the limbic system plays a distinct role in emotion:<\/p>\n<ul>\n<li>The hypothalamus plays a role in the activation of the sympathetic nervous system that is a part of any given emotional reaction.<\/li>\n<li>The thalamus serves as a sensory relay center whose neurons project to both the amygdala and the higher cortical regions for further processing.<\/li>\n<li>The amygdala plays a role in processing emotional information and sending that information on to cortical structures (Fossati, 2012).<\/li>\n<li>The hippocampus integrates emotional experiences with cognition (Femen\u00eda, G\u00f3mez-Gal\u00e1n, Lindskog, &amp; Magara, 2012).<\/li>\n<\/ul>\n<p>Let&#8217;s take a closer look at the amygdala and the hippocampus and their roles in emotion.<\/p>\n<section class=\"textbox keyTakeaway\">\n<h3>structure and function of the amygdala<\/h3>\n<p>The <strong>amygdala<\/strong> has received a great deal of attention from researchers interested in understanding the biological basis for emotions, especially the emotions of fear and anxiety (Blackford &amp; Pine, 2012; Goosens &amp; Maren, 2002; Maren, Phan, &amp; Liberzon, 2013). The amygdala is composed of various subnuclei (neural subcomponents), including the basolateral complex and the central nucleus.<\/p>\n<p>The <strong>basolateral complex<\/strong> has dense connections with a variety of sensory areas of the brain. It is critical for classical conditioning and for attaching emotional value to learning processes and memory.<\/p>\n<p>The <strong>central nucleus<\/strong> plays a role in attention, and it has connections with the hypothalamus and various brainstem areas to regulate the autonomic nervous and endocrine systems\u2019 activity (Pessoa, 2010).<\/p>\n<figure id=\"attachment_6917\" aria-describedby=\"caption-attachment-6917\" style=\"width: 394px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/855\/2016\/11\/03232140\/79bfd30ce14938bbbf36af8f5be3f283b4fc5cba.jpeg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-6917\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/855\/2016\/11\/03232140\/79bfd30ce14938bbbf36af8f5be3f283b4fc5cba.jpeg\" alt=\"An illustration of the brain labels the locations of the \u201cbasolateral complex\u201d and \u201ccentral nucleus\u201d within the \u201camygdala.\u201d\" width=\"394\" height=\"400\" \/><\/a><figcaption id=\"caption-attachment-6917\" class=\"wp-caption-text\"><strong>Figure 2<\/strong>. The anatomy of the basolateral complex and central nucleus of the amygdala are illustrated in this diagram.<\/figcaption><\/figure>\n<\/section>\n<section class=\"textbox example\">\n<h3><b>A story from animal research: context matters<\/b><\/h3>\n<p class=\"p3\">One striking set of studies shows that the amygdala\u2019s role in learning fear can depend heavily on <span class=\"s2\">context<\/span>.<\/p>\n<p class=\"p3\">Researchers found that rat pups who experienced an odor paired with a mild shock <span class=\"s2\">without their mother present<\/span> showed increased amygdala activation and later avoided that odor\u2014suggesting they learned fear.<\/p>\n<p class=\"p3\">But when the <span class=\"s2\">mother was present<\/span>, the pups actually showed a <span class=\"s2\">preference<\/span> for the odor cue, even though it had been paired with a shock. In that condition, the amygdala did <i>not<\/i> show the same increase in activation. In other words, the mother\u2019s presence changed how the pups\u2019 brains responded\u2014and what they learned (Moriceau &amp; Sullivan, 2006).<\/p>\n<\/section>\n<section data-depth=\"2\">\n<h3><b>Early experience and later emotional patterns<\/b><\/h3>\n<p class=\"p3\">Related work suggests that adverse early experiences can alter amygdala functioning in ways that shape later behavior. In one study, rat pups exposed to stressful or abusive-like conditions early in life later showed more \u201cdepressive-like\u201d behavior during adolescence, along with increased amygdala activation (Raineki et al., 2012).<\/p>\n<p class=\"p3\">While we should be cautious about directly translating rat findings to humans, this research supports a broader point: early experiences can influence how brain systems involved in threat and emotion develop over time.<\/p>\n<h3><b>Links to human mood and anxiety disorders<\/b><\/h3>\n<p class=\"p3\">Human research also finds associations between amygdala structure\/function and disorders involving mood and anxiety. Differences in amygdala activity have been observed in adolescents who are at risk for\u2014or diagnosed with\u2014certain anxiety or mood disorders. Some researchers have also explored whether patterns of amygdala activation could help distinguish between conditions such as bipolar disorder and major depressive disorder (though this remains an area of ongoing research).<\/p>\n<\/section>\n<section data-depth=\"2\">\n<h3>Hippocampus<\/h3>\n<p class=\"p1\">The <span class=\"s1\"><b>hippocampus<\/b><\/span> is also important in emotional processing, especially because it supports <span class=\"s1\"><b>memory and context<\/b><\/span>. That context matters for emotion: it helps your brain answer questions like, \u201cIs this situation safe?\u201d or \u201cHave I been here before?\u201d<\/p>\n<p class=\"p1\">Research links hippocampal structure and function to several mood and anxiety disorders. For example, studies of people with <span class=\"s1\"><b>posttraumatic stress disorder (PTSD)<\/b><\/span> often find reduced volume in parts of the hippocampus. Some researchers suggest these patterns may relate to changes in neurogenesis and dendritic branching (the growth of new neurons and new neural connections).<\/p>\n<p class=\"p1\">It\u2019s important to note that many of these studies are correlational, so they cannot prove cause and effect. However, some work suggests that after treatment (including medication and\/or cognitive-behavioral therapy), people with PTSD may show symptom improvement alongside changes in hippocampal functioning and, in some cases, volume measures.<\/p>\n<section class=\"textbox tryIt\"><iframe loading=\"lazy\" id=\"ohm4415\" class=\"resizable\" src=\"https:\/\/ohm.one.lumenlearning.com\/multiembedq.php?id=4415&theme=lumen&iframe_resize_id=ohm4415&source=tnh&show_question_numbers\" width=\"100%\" height=\"350\"><\/iframe><\/section>\n<\/section>\n","protected":false},"author":20,"menu_order":27,"template":"","meta":{"_candela_citation":"[{\"type\":\"cc\",\"description\":\"Emotion\",\"author\":\"OpenStax College\",\"organization\":\"\",\"url\":\"https:\/\/openstax.org\/books\/psychology-2e\/pages\/10-4-emotion\",\"project\":\"\",\"license\":\"cc-by\",\"license_terms\":\"Download for free at https:\/\/openstax.org\/books\/psychology-2e\/pages\/1-introduction\"}]","pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[],"license":[],"part":711,"module-header":"learn_it","content_attributions":[{"type":"cc","description":"Emotion","author":"OpenStax College","organization":"","url":"https:\/\/openstax.org\/books\/psychology-2e\/pages\/10-4-emotion","project":"","license":"cc-by","license_terms":"Download for free at https:\/\/openstax.org\/books\/psychology-2e\/pages\/1-introduction"}],"internal_book_links":[],"video_content":null,"cc_video_embed_content":{"cc_scripts":"","media_targets":[]},"try_it_collection":null,"_links":{"self":[{"href":"https:\/\/content.one.lumenlearning.com\/introductiontopsychology\/wp-json\/pressbooks\/v2\/chapters\/728"}],"collection":[{"href":"https:\/\/content.one.lumenlearning.com\/introductiontopsychology\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/content.one.lumenlearning.com\/introductiontopsychology\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/content.one.lumenlearning.com\/introductiontopsychology\/wp-json\/wp\/v2\/users\/20"}],"version-history":[{"count":21,"href":"https:\/\/content.one.lumenlearning.com\/introductiontopsychology\/wp-json\/pressbooks\/v2\/chapters\/728\/revisions"}],"predecessor-version":[{"id":7507,"href":"https:\/\/content.one.lumenlearning.com\/introductiontopsychology\/wp-json\/pressbooks\/v2\/chapters\/728\/revisions\/7507"}],"part":[{"href":"https:\/\/content.one.lumenlearning.com\/introductiontopsychology\/wp-json\/pressbooks\/v2\/parts\/711"}],"metadata":[{"href":"https:\/\/content.one.lumenlearning.com\/introductiontopsychology\/wp-json\/pressbooks\/v2\/chapters\/728\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/content.one.lumenlearning.com\/introductiontopsychology\/wp-json\/wp\/v2\/media?parent=728"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/content.one.lumenlearning.com\/introductiontopsychology\/wp-json\/pressbooks\/v2\/chapter-type?post=728"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/content.one.lumenlearning.com\/introductiontopsychology\/wp-json\/wp\/v2\/contributor?post=728"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/content.one.lumenlearning.com\/introductiontopsychology\/wp-json\/wp\/v2\/license?post=728"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}