{"id":2982,"date":"2019-05-29T14:28:45","date_gmt":"2019-05-29T14:28:45","guid":{"rendered":"https:\/\/courses.lumenlearning.com\/wm-lifespandevelopment\/?post_type=chapter&#038;p=2982"},"modified":"2024-04-30T19:19:56","modified_gmt":"2024-04-30T19:19:56","slug":"brain-development-during-adolescence","status":"publish","type":"chapter","link":"https:\/\/courses.lumenlearning.com\/wm-lifespandevelopment\/chapter\/brain-development-during-adolescence\/","title":{"raw":"Brain Development During Adolescence","rendered":"Brain Development During Adolescence"},"content":{"raw":"<div class=\"textbox learning-objectives\">\r\n<h3>Learning Outcomes<\/h3>\r\n<ul>\r\n \t<li>Describe brain development during adolescence<\/li>\r\n<\/ul>\r\n<\/div>\r\n<p id=\"fs-idp52884496\">The human brain is not fully developed by the time a person reaches puberty. Between the ages of 10 and 25, the brain undergoes changes that have important implications for behavior. The brain reaches 90% of its adult size by the time a person is six or seven years of age.\u00a0<sup id=\"cite_ref-Casey,_B._J._2008_56-0\" class=\"reference\"><\/sup>Thus, the brain does not grow in size much during adolescence. However, the creases in the brain continue to become more complex until the late teens. The biggest changes in the folds of the brain during this time occur in the parts of the cortex that process cognitive and emotional information.<\/p>\r\nUp until puberty, brain cells continue to bloom in the frontal region. Some of the most developmentally significant changes in t<span style=\"font-size: 1rem; text-align: initial;\">he brain occur in the <strong>prefrontal cortex<\/strong>, which is involved in\u00a0<\/span>decision making<span style=\"font-size: 1rem; text-align: initial;\">\u00a0and cognitive control, as well as other higher cognitive functions.\u00a0During adolescence, <strong>myelination<\/strong> and <strong>synaptic pruning<\/strong> in the prefrontal cortex increase<del>s<\/del>, improving the efficiency of information processing, and neural connections between the prefrontal cortex and other regions of the brain are strengthened.\u00a0However, this growth takes time and the growth is uneven.<\/span>\r\n<div class=\"textbox key-takeaways\">\r\n<h3><strong>The Teen Brain: 6 Things to Know<\/strong><\/h3>\r\n[caption id=\"attachment_4480\" align=\"alignright\" width=\"487\"]<img class=\"wp-image-4480\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/3707\/2019\/05\/09124739\/Screen-Shot-2019-07-09-at-8.46.19-AM.png\" alt=\"An illustration of a baby developing to a teenager alongside brains developing in mass and connections.\" width=\"487\" height=\"365\" \/> <strong>Figure 1<\/strong>. The brain reaches its largest size in the early teen years, but continues to mature well into the 20s.[\/caption]\r\n\r\nAs you learn about brain development during adolescence, consider these six facts from the <a href=\"https:\/\/www.nimh.nih.gov\/health\/publications\/the-teen-brain-6-things-to-know\/index.shtml#pub4\" target=\"_blank\" rel=\"noopener\">The National Institute of Mental Health<\/a>:\r\n<h4 id=\"pub1\" class=\"pubsection clearer\">Your brain does not keep getting bigger as you get older<\/h4>\r\nFor girls, the brain reaches its largest physical size around 11 years old and for boys, the brain reaches its largest physical size around age 14. Of course, this difference in age does not mean either boys or girls are smarter than one another!\r\n<h4 id=\"pub2\" class=\"pubsection clearer\">But that doesn\u2019t mean your brain is done maturing<\/h4>\r\nFor both boys and girls, although your brain may be as large as it will ever be, your brain doesn't finish developing and maturing until your mid- to late-20s. The front part of the brain, called the prefrontal cortex, is one of the last brain regions to mature. It is the area responsible for planning, prioritizing and controlling impulses.\r\n<h4 id=\"pub3\" class=\"pubsection clearer\">The teen brain is ready to learn and adapt<\/h4>\r\nIn a digital world that is constantly changing, the adolescent brain is well prepared to adapt to new technology\u2014and is shaped in return by experience.\r\n<h4 id=\"pub4\" class=\"pubsection clearer\">Many mental disorders appear during adolescence<\/h4>\r\nAll the big changes the brain is experiencing may explain why adolescence is the time when many mental disorders\u2014such as schizophrenia, anxiety, depression, bipolar disorder, and eating disorders\u2014emerge.\r\n<h4 id=\"pub5\" class=\"pubsection clearer\">The teen brain is resilient<\/h4>\r\nAlthough adolescence is a vulnerable time for the brain and for teenagers in general, most teens go on to become healthy adults. Some changes in the brain during this important phase of development actually may help protect against long-term mental disorders.\r\n<h4 id=\"pub6\" class=\"pubsection clearer\">Teens need more sleep than children and adults<\/h4>\r\nAlthough it may seem like teens are lazy, science shows that <strong>melatonin<\/strong> levels (or the \"sleep hormone\" levels) in the blood naturally rise later at night and fall later in the morning than in most children and adults. This may explain why many teens stay up late and struggle with getting up in the morning. Teens should get about 9-10 hours of sleep a night, but most teens don\u2019t get enough sleep. A lack of sleep makes paying attention hard, increases impulsivity and may also increase irritability and depression.\r\n\r\n<\/div>\r\n<span style=\"font-size: 1rem; text-align: initial;\">The <strong>limbic system<\/strong> develops years ahead of the prefrontal cortex. Development in the limbic system plays an important role in determining rewards and punishments and processing emotional experience and social information. Pubertal hormones target the <strong>amygdala<\/strong> directly and powerful sensations become compelling (Romeo, 2013). [footnote]Romeo, R.D. (2013). The teenage brain: The stress response and the adolescent brain. Current Directions in Psychological Science, 22 (2), 140-145.[\/footnote] Brain scans confirm that cognitive control, revealed by fMRI studies, is not fully developed until adulthood because the prefrontal cortex is limited in connections and engagement (Hartley &amp; Somerville, 2015).\u00a0[footnote]Hartley, C.A. &amp; Somerville, L.H. (2015). The neuroscience of adolescent decision-making. Current Opinion in Behavioral Sciences, 5, 108-115.[\/footnote] Recall that this area is responsible for judgment, impulse control, and planning, and it is still maturing into early adulthood (Casey, Tottenham, Liston, &amp; Durston, 2005).\u00a0<\/span>\r\n\r\n[caption id=\"\" align=\"alignleft\" width=\"408\"]<a href=\"https:\/\/s3-us-west-2.amazonaws.com\/candimgs\/FVMtfI\/CNX_Psych_09_04_TeenBrain.jpgfixme\"><img src=\"https:\/\/s3-us-west-2.amazonaws.com\/candimgs\/FVMtfI\/CNX_Psych_09_04_TeenBrain.jpgfixme\" alt=\"An illustration of a brain is shown with the frontal lobe labeled.\" width=\"408\" height=\"303\" \/><\/a> <strong>Figure 2<\/strong>. Brain development continues into the early 20s. The development of the frontal lobe, in particular, is important during this stage.[\/caption]\r\n\r\nAdditionally, changes in both the levels of the neurotransmitters <strong>dopamine<\/strong> and\u00a0<strong>serotonin<\/strong>\u00a0in the limbic system make adolescents more emotional and more responsive to rewards and stress. Dopamine\u00a0is a neurotransmitter in the brain associated with pleasure and attuning to the environment during decision-making. During adolescence, dopamine levels in the\u00a0limbic system\u00a0increase and input of dopamine to the prefrontal cortex increases.\u00a0The increased dopamine activity in adolescence may have implications for adolescent risk-taking and vulnerability to boredom.\u00a0Serotonin is\u00a0involved in the regulation of mood and behavior. It affects the brain in a different way. Known as the \u201ccalming chemical,\u201d serotonin eases tension and stress. Serotonin also puts a brake on the excitement and sometimes recklessness that dopamine can produce. If there is a defect in the serotonin processing in the brain, impulsive or violent behavior can result.\r\n\r\nWhen the overall brain chemical system is working well, it seems that these chemicals interact to balance out extreme behaviors. But w<span style=\"font-size: 1rem; text-align: initial;\">hen stress, arousal or sensations become extreme, the adolescent brain is flooded with impulses that overwhelm the prefrontal cortex, and as a result, a<\/span>dolescents engage in increased risk-taking behaviors and emotional outbursts possibly because the frontal lobes of their brains are still developing.\r\n\r\nLater in adolescence, the brain\u2019s cognitive control centers in the prefrontal cortex develop, increasing adolescents\u2019 self-regulation and future orientation. The difference in timing of the development of these different regions of the brain contributes to more risk taking during middle adolescence because adolescents are motivated to seek thrills that sometimes come from risky behavior, such as reckless driving, smoking, or drinking, and have not yet developed the cognitive control to resist impulses or focus equally on the potential risks (Steinberg, 2008). [footnote]Steinberg, L. (2013). Adolescence (10th ed.). New York, NY: McGraw-Hill.[\/footnote] One of the world\u2019s leading experts on adolescent development, Laurence Steinberg, likens this to engaging a powerful engine before the braking system is in place. The result is that adolescents are more prone to risky behaviors than are children or adults.\r\n<div class=\"textbox examples\">\r\n<h3>Watch IT<\/h3>\r\nThis video further explains and highlights some of the key developments in the brain during adolescence.\r\n\r\n<iframe src=\"\/\/plugin.3playmedia.com\/show?mf=3935317&amp;p3sdk_version=1.10.1&amp;p=20361&amp;pt=375&amp;video_id=5Fa8U6BkhNo&amp;video_target=tpm-plugin-h4g9zwmf-5Fa8U6BkhNo\" width=\"800px\" height=\"520px\" frameborder=\"0\" marginwidth=\"0px\" marginheight=\"0px\"><\/iframe>\r\n\r\nYou can <a href=\"https:\/\/oerfiles.s3-us-west-2.amazonaws.com\/Lifespan+Development\/Transcriptions\/BrainChangesDuringAdolescence_transcript.txt\" target=\"_blank\" rel=\"noopener\">view the transcript for \"Brain changes during adolescence | Behavior | MCAT | Khan Academy\" here (opens in new window)<\/a>.\r\n\r\n<\/div>\r\nAs mentioned in the introduction to adolescence, too many who have read the research on the teenage brain come to quick conclusions about adolescents as irrational loose cannons. However, adolescents are actually making choices influenced by a very different set of chemical influences than their adult counterparts\u2014a hopped up reward system that can drown out warning\u00a0signals about risk. Adolescent decisions are not always defined by impulsivity because of lack of brakes, but because of planned and enjoyable pressure to the accelerator.\u00a0It is helpful to put all of these brain processes in developmental context. Young people need to somewhat enjoy the thrill of risk taking in order to complete the incredibly overwhelming task of growing up.\r\n<div class=\"textbox examples\">\r\n<h3>Watch It<\/h3>\r\nWatch the selected portion of this video to learn more about research related to brain changes and behavior during adolescence.\r\n\r\nhttps:\/\/youtu.be\/hiduiTq1ei8?t=239\r\n\r\nYou can <a href=\"https:\/\/oerfiles.s3-us-west-2.amazonaws.com\/Lifespan+Development\/Transcriptions\/TheTeenageBrainExplained_transcript.txt\" target=\"_blank\" rel=\"noopener\">view the transcript for \"The Teenage Brain Explained\" here (opens in new window)<\/a>.\r\n\r\nTo learn more, watch this <a href=\"https:\/\/www.youtube.com\/watch?v=6zVS8HIPUng\">TED talk by Sarah-Jayne Blakemore: The mysterious workings of the adolescent brain<\/a>\u00a0about the latest adolescent brain research and more about how these changes in brain development also result in behavioral changes.\r\n\r\n<\/div>\r\n<div class=\"textbox key-takeaways\">\r\n<h3>Key Takeaways<\/h3>\r\nIn sum, the adolescent years are a time of intense brain changes. Interestingly, two of the primary brain functions develop at different rates. Brain research indicates that the part of the brain that perceives rewards from risk, the limbic system, kicks into high gear in early adolescence. The part of the brain that controls impulses and engages in longer-term perspective, the frontal lobes, mature<del>s<\/del> later. This may explain why teens in mid-adolescence take more risks than older teens. As the frontal lobes become more developed, two things happen. First, self-control develops as teens are better able to assess cause and effect. Second, more areas of the brain become involved in processing emotions, and teens become better at accurately interpreting others\u2019 emotions.[footnote]Steinberg, L. (2008) A social neuroscience perspective on adolescent risk-taking. Developmental Review, 28:78-106.[\/footnote]\r\n\r\n<\/div>\r\n<div class=\"textbox tryit\">\r\n<h3>Try It<\/h3>\r\nhttps:\/\/assess.lumenlearning.com\/practice\/054b2243-dc9c-442f-bcc0-188a10168cc0\r\n\r\n<\/div>\r\n<h2>Sleep<\/h2>\r\nBrain development even affects the way teens sleep. Adolescents\u2019 normal sleep patterns are different from those of children and adults. Teens are often drowsy upon waking, tired during the day, and wakeful at night. See the sixth fact in \"The Teen Brain\" section above for more details. [footnote]National Institute of Mental Health. The Teen Brain: 6 Things to Know. Retrieved from\u00a0https:\/\/www.nimh.nih.gov\/health\/publications\/the-teen-brain-6-things-to-know\/index.shtml#pub6.[\/footnote]\r\n<div class=\"textbox exercises\">\r\n<h3>Link to Learning: School Start Times<\/h3>\r\nAs research reveals the importance of sleep for teenagers, many people advocate for later high school start times. Read about some of the <a href=\"https:\/\/www.sleepfoundation.org\/articles\/backgrounder-later-school-start-times\" target=\"_blank\" rel=\"noopener\">research at the National Sleep Foundation on school start times<\/a>\u00a0or watch this <a href=\"https:\/\/www.ted.com\/talks\/wendy_troxel_why_school_should_start_later_for_teens\/transcript?language=en\">TED talk by Wendy Troxel: \"Why Schools Should Start Later for Teens\"<\/a>.\r\n\r\n<\/div>\r\n<div class=\"textbox key-takeaways\">\r\n<h3>glossary<\/h3>\r\n[glossary-page]\r\n[glossary-term]amygdala:[\/glossary-term]\r\n[glossary-definition]part of the limbic system in the brain, which is involved with emotions and emotional responses and is particularly active during puberty[\/glossary-definition]\r\n\r\n[glossary-term]dopamine:[\/glossary-term]\r\n[glossary-definition]a neurotransmitter in the brain that plays a role in pleasure and the reward system; increases in the limbic system and later in the prefrontal cortex during adolescence[\/glossary-definition]\r\n\r\n[glossary-term]frontal lobes:[\/glossary-term]\r\n[glossary-definition]the parts of the brain involved in impulse control, planning, and higher order thinking; still developing in adolescence[\/glossary-definition]\r\n\r\n[glossary-term]limbic system:[\/glossary-term]\r\n[glossary-definition]structures in the brain (including the amygdala) that involve processing emotional experience and social information and determining rewards and punishments; develops years before the prefrontal cortex[\/glossary-definition]\r\n\r\n[glossary-term]melatonin:[\/glossary-term]\r\n[glossary-definition]sleep hormone whose levels rise later at night and decrease later in the morning for teens, compared to children and adults[\/glossary-definition]\r\n\r\n[glossary-term]myelination:[\/glossary-term]\r\n[glossary-definition]insulation of neurons' axons with fatty substance (myelin sheath) that helps speed up the processing of information; myelination starts to increase in the prefrontal cortex during adolescence[\/glossary-definition]\r\n\r\n[glossary-term]prefrontal cortex:[\/glossary-term]\r\n[glossary-definition]part of the frontal lobes, involved with decision making, cognitive control, and other higher order functions; prefrontal cortex develops further during adolescence[\/glossary-definition]\r\n\r\n[glossary-term]serotonin:[\/glossary-term]\r\n[glossary-definition]\"calming chemical,\" a neurotransmitter in the brain involved with the regulation of mood and behavior; serotonin levels increase in the limbic system during adolescence[\/glossary-definition]\r\n\r\n[glossary-term]synaptic pruning:[\/glossary-term]\r\n[glossary-definition]connections in the brain that are not used much are lost so that other connections can be strengthened; this pruning happens with prefrontal cortex connections in adolescence[\/glossary-definition]\r\n[\/glossary-page]\r\n\r\n<\/div>","rendered":"<div class=\"textbox learning-objectives\">\n<h3>Learning Outcomes<\/h3>\n<ul>\n<li>Describe brain development during adolescence<\/li>\n<\/ul>\n<\/div>\n<p id=\"fs-idp52884496\">The human brain is not fully developed by the time a person reaches puberty. Between the ages of 10 and 25, the brain undergoes changes that have important implications for behavior. The brain reaches 90% of its adult size by the time a person is six or seven years of age.\u00a0<sup id=\"cite_ref-Casey,_B._J._2008_56-0\" class=\"reference\"><\/sup>Thus, the brain does not grow in size much during adolescence. However, the creases in the brain continue to become more complex until the late teens. The biggest changes in the folds of the brain during this time occur in the parts of the cortex that process cognitive and emotional information.<\/p>\n<p>Up until puberty, brain cells continue to bloom in the frontal region. Some of the most developmentally significant changes in t<span style=\"font-size: 1rem; text-align: initial;\">he brain occur in the <strong>prefrontal cortex<\/strong>, which is involved in\u00a0<\/span>decision making<span style=\"font-size: 1rem; text-align: initial;\">\u00a0and cognitive control, as well as other higher cognitive functions.\u00a0During adolescence, <strong>myelination<\/strong> and <strong>synaptic pruning<\/strong> in the prefrontal cortex increase<del>s<\/del>, improving the efficiency of information processing, and neural connections between the prefrontal cortex and other regions of the brain are strengthened.\u00a0However, this growth takes time and the growth is uneven.<\/span><\/p>\n<div class=\"textbox key-takeaways\">\n<h3><strong>The Teen Brain: 6 Things to Know<\/strong><\/h3>\n<div id=\"attachment_4480\" style=\"width: 497px\" class=\"wp-caption alignright\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-4480\" class=\"wp-image-4480\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/3707\/2019\/05\/09124739\/Screen-Shot-2019-07-09-at-8.46.19-AM.png\" alt=\"An illustration of a baby developing to a teenager alongside brains developing in mass and connections.\" width=\"487\" height=\"365\" \/><\/p>\n<p id=\"caption-attachment-4480\" class=\"wp-caption-text\"><strong>Figure 1<\/strong>. The brain reaches its largest size in the early teen years, but continues to mature well into the 20s.<\/p>\n<\/div>\n<p>As you learn about brain development during adolescence, consider these six facts from the <a href=\"https:\/\/www.nimh.nih.gov\/health\/publications\/the-teen-brain-6-things-to-know\/index.shtml#pub4\" target=\"_blank\" rel=\"noopener\">The National Institute of Mental Health<\/a>:<\/p>\n<h4 id=\"pub1\" class=\"pubsection clearer\">Your brain does not keep getting bigger as you get older<\/h4>\n<p>For girls, the brain reaches its largest physical size around 11 years old and for boys, the brain reaches its largest physical size around age 14. Of course, this difference in age does not mean either boys or girls are smarter than one another!<\/p>\n<h4 id=\"pub2\" class=\"pubsection clearer\">But that doesn\u2019t mean your brain is done maturing<\/h4>\n<p>For both boys and girls, although your brain may be as large as it will ever be, your brain doesn&#8217;t finish developing and maturing until your mid- to late-20s. The front part of the brain, called the prefrontal cortex, is one of the last brain regions to mature. It is the area responsible for planning, prioritizing and controlling impulses.<\/p>\n<h4 id=\"pub3\" class=\"pubsection clearer\">The teen brain is ready to learn and adapt<\/h4>\n<p>In a digital world that is constantly changing, the adolescent brain is well prepared to adapt to new technology\u2014and is shaped in return by experience.<\/p>\n<h4 id=\"pub4\" class=\"pubsection clearer\">Many mental disorders appear during adolescence<\/h4>\n<p>All the big changes the brain is experiencing may explain why adolescence is the time when many mental disorders\u2014such as schizophrenia, anxiety, depression, bipolar disorder, and eating disorders\u2014emerge.<\/p>\n<h4 id=\"pub5\" class=\"pubsection clearer\">The teen brain is resilient<\/h4>\n<p>Although adolescence is a vulnerable time for the brain and for teenagers in general, most teens go on to become healthy adults. Some changes in the brain during this important phase of development actually may help protect against long-term mental disorders.<\/p>\n<h4 id=\"pub6\" class=\"pubsection clearer\">Teens need more sleep than children and adults<\/h4>\n<p>Although it may seem like teens are lazy, science shows that <strong>melatonin<\/strong> levels (or the &#8220;sleep hormone&#8221; levels) in the blood naturally rise later at night and fall later in the morning than in most children and adults. This may explain why many teens stay up late and struggle with getting up in the morning. Teens should get about 9-10 hours of sleep a night, but most teens don\u2019t get enough sleep. A lack of sleep makes paying attention hard, increases impulsivity and may also increase irritability and depression.<\/p>\n<\/div>\n<p><span style=\"font-size: 1rem; text-align: initial;\">The <strong>limbic system<\/strong> develops years ahead of the prefrontal cortex. Development in the limbic system plays an important role in determining rewards and punishments and processing emotional experience and social information. Pubertal hormones target the <strong>amygdala<\/strong> directly and powerful sensations become compelling (Romeo, 2013). <a class=\"footnote\" title=\"Romeo, R.D. (2013). The teenage brain: The stress response and the adolescent brain. Current Directions in Psychological Science, 22 (2), 140-145.\" id=\"return-footnote-2982-1\" href=\"#footnote-2982-1\" aria-label=\"Footnote 1\"><sup class=\"footnote\">[1]<\/sup><\/a> Brain scans confirm that cognitive control, revealed by fMRI studies, is not fully developed until adulthood because the prefrontal cortex is limited in connections and engagement (Hartley &amp; Somerville, 2015).\u00a0<a class=\"footnote\" title=\"Hartley, C.A. &amp; Somerville, L.H. (2015). The neuroscience of adolescent decision-making. Current Opinion in Behavioral Sciences, 5, 108-115.\" id=\"return-footnote-2982-2\" href=\"#footnote-2982-2\" aria-label=\"Footnote 2\"><sup class=\"footnote\">[2]<\/sup><\/a> Recall that this area is responsible for judgment, impulse control, and planning, and it is still maturing into early adulthood (Casey, Tottenham, Liston, &amp; Durston, 2005).\u00a0<\/span><\/p>\n<div style=\"width: 418px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/s3-us-west-2.amazonaws.com\/candimgs\/FVMtfI\/CNX_Psych_09_04_TeenBrain.jpgfixme\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/candimgs\/FVMtfI\/CNX_Psych_09_04_TeenBrain.jpgfixme\" alt=\"An illustration of a brain is shown with the frontal lobe labeled.\" width=\"408\" height=\"303\" \/><\/a><\/p>\n<p class=\"wp-caption-text\"><strong>Figure 2<\/strong>. Brain development continues into the early 20s. The development of the frontal lobe, in particular, is important during this stage.<\/p>\n<\/div>\n<p>Additionally, changes in both the levels of the neurotransmitters <strong>dopamine<\/strong> and\u00a0<strong>serotonin<\/strong>\u00a0in the limbic system make adolescents more emotional and more responsive to rewards and stress. Dopamine\u00a0is a neurotransmitter in the brain associated with pleasure and attuning to the environment during decision-making. During adolescence, dopamine levels in the\u00a0limbic system\u00a0increase and input of dopamine to the prefrontal cortex increases.\u00a0The increased dopamine activity in adolescence may have implications for adolescent risk-taking and vulnerability to boredom.\u00a0Serotonin is\u00a0involved in the regulation of mood and behavior. It affects the brain in a different way. Known as the \u201ccalming chemical,\u201d serotonin eases tension and stress. Serotonin also puts a brake on the excitement and sometimes recklessness that dopamine can produce. If there is a defect in the serotonin processing in the brain, impulsive or violent behavior can result.<\/p>\n<p>When the overall brain chemical system is working well, it seems that these chemicals interact to balance out extreme behaviors. But w<span style=\"font-size: 1rem; text-align: initial;\">hen stress, arousal or sensations become extreme, the adolescent brain is flooded with impulses that overwhelm the prefrontal cortex, and as a result, a<\/span>dolescents engage in increased risk-taking behaviors and emotional outbursts possibly because the frontal lobes of their brains are still developing.<\/p>\n<p>Later in adolescence, the brain\u2019s cognitive control centers in the prefrontal cortex develop, increasing adolescents\u2019 self-regulation and future orientation. The difference in timing of the development of these different regions of the brain contributes to more risk taking during middle adolescence because adolescents are motivated to seek thrills that sometimes come from risky behavior, such as reckless driving, smoking, or drinking, and have not yet developed the cognitive control to resist impulses or focus equally on the potential risks (Steinberg, 2008). <a class=\"footnote\" title=\"Steinberg, L. (2013). Adolescence (10th ed.). New York, NY: McGraw-Hill.\" id=\"return-footnote-2982-3\" href=\"#footnote-2982-3\" aria-label=\"Footnote 3\"><sup class=\"footnote\">[3]<\/sup><\/a> One of the world\u2019s leading experts on adolescent development, Laurence Steinberg, likens this to engaging a powerful engine before the braking system is in place. The result is that adolescents are more prone to risky behaviors than are children or adults.<\/p>\n<div class=\"textbox examples\">\n<h3>Watch IT<\/h3>\n<p>This video further explains and highlights some of the key developments in the brain during adolescence.<\/p>\n<p><iframe loading=\"lazy\" src=\"\/\/plugin.3playmedia.com\/show?mf=3935317&amp;p3sdk_version=1.10.1&amp;p=20361&amp;pt=375&amp;video_id=5Fa8U6BkhNo&amp;video_target=tpm-plugin-h4g9zwmf-5Fa8U6BkhNo\" width=\"800px\" height=\"520px\" frameborder=\"0\" marginwidth=\"0px\" marginheight=\"0px\"><\/iframe><\/p>\n<p>You can <a href=\"https:\/\/oerfiles.s3-us-west-2.amazonaws.com\/Lifespan+Development\/Transcriptions\/BrainChangesDuringAdolescence_transcript.txt\" target=\"_blank\" rel=\"noopener\">view the transcript for &#8220;Brain changes during adolescence | Behavior | MCAT | Khan Academy&#8221; here (opens in new window)<\/a>.<\/p>\n<\/div>\n<p>As mentioned in the introduction to adolescence, too many who have read the research on the teenage brain come to quick conclusions about adolescents as irrational loose cannons. However, adolescents are actually making choices influenced by a very different set of chemical influences than their adult counterparts\u2014a hopped up reward system that can drown out warning\u00a0signals about risk. Adolescent decisions are not always defined by impulsivity because of lack of brakes, but because of planned and enjoyable pressure to the accelerator.\u00a0It is helpful to put all of these brain processes in developmental context. Young people need to somewhat enjoy the thrill of risk taking in order to complete the incredibly overwhelming task of growing up.<\/p>\n<div class=\"textbox examples\">\n<h3>Watch It<\/h3>\n<p>Watch the selected portion of this video to learn more about research related to brain changes and behavior during adolescence.<\/p>\n<p><iframe loading=\"lazy\" id=\"oembed-1\" title=\"How Teenagers&#39; Brains Are Actually Wired Differently\" width=\"500\" height=\"281\" src=\"https:\/\/www.youtube.com\/embed\/hiduiTq1ei8?start=239&#38;feature=oembed\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\"><\/iframe><\/p>\n<p>You can <a href=\"https:\/\/oerfiles.s3-us-west-2.amazonaws.com\/Lifespan+Development\/Transcriptions\/TheTeenageBrainExplained_transcript.txt\" target=\"_blank\" rel=\"noopener\">view the transcript for &#8220;The Teenage Brain Explained&#8221; here (opens in new window)<\/a>.<\/p>\n<p>To learn more, watch this <a href=\"https:\/\/www.youtube.com\/watch?v=6zVS8HIPUng\">TED talk by Sarah-Jayne Blakemore: The mysterious workings of the adolescent brain<\/a>\u00a0about the latest adolescent brain research and more about how these changes in brain development also result in behavioral changes.<\/p>\n<\/div>\n<div class=\"textbox key-takeaways\">\n<h3>Key Takeaways<\/h3>\n<p>In sum, the adolescent years are a time of intense brain changes. Interestingly, two of the primary brain functions develop at different rates. Brain research indicates that the part of the brain that perceives rewards from risk, the limbic system, kicks into high gear in early adolescence. The part of the brain that controls impulses and engages in longer-term perspective, the frontal lobes, mature<del>s<\/del> later. This may explain why teens in mid-adolescence take more risks than older teens. As the frontal lobes become more developed, two things happen. First, self-control develops as teens are better able to assess cause and effect. Second, more areas of the brain become involved in processing emotions, and teens become better at accurately interpreting others\u2019 emotions.<a class=\"footnote\" title=\"Steinberg, L. (2008) A social neuroscience perspective on adolescent risk-taking. Developmental Review, 28:78-106.\" id=\"return-footnote-2982-4\" href=\"#footnote-2982-4\" aria-label=\"Footnote 4\"><sup class=\"footnote\">[4]<\/sup><\/a><\/p>\n<\/div>\n<div class=\"textbox tryit\">\n<h3>Try It<\/h3>\n<p>\t<iframe id=\"assessment_practice_054b2243-dc9c-442f-bcc0-188a10168cc0\" class=\"resizable\" src=\"https:\/\/assess.lumenlearning.com\/practice\/054b2243-dc9c-442f-bcc0-188a10168cc0?iframe_resize_id=assessment_practice_id_054b2243-dc9c-442f-bcc0-188a10168cc0\" frameborder=\"0\" style=\"border:none;width:100%;height:100%;min-height:300px;\"><br \/>\n\t<\/iframe><\/p>\n<\/div>\n<h2>Sleep<\/h2>\n<p>Brain development even affects the way teens sleep. Adolescents\u2019 normal sleep patterns are different from those of children and adults. Teens are often drowsy upon waking, tired during the day, and wakeful at night. See the sixth fact in &#8220;The Teen Brain&#8221; section above for more details. <a class=\"footnote\" title=\"National Institute of Mental Health. The Teen Brain: 6 Things to Know. Retrieved from\u00a0https:\/\/www.nimh.nih.gov\/health\/publications\/the-teen-brain-6-things-to-know\/index.shtml#pub6.\" id=\"return-footnote-2982-5\" href=\"#footnote-2982-5\" aria-label=\"Footnote 5\"><sup class=\"footnote\">[5]<\/sup><\/a><\/p>\n<div class=\"textbox exercises\">\n<h3>Link to Learning: School Start Times<\/h3>\n<p>As research reveals the importance of sleep for teenagers, many people advocate for later high school start times. Read about some of the <a href=\"https:\/\/www.sleepfoundation.org\/articles\/backgrounder-later-school-start-times\" target=\"_blank\" rel=\"noopener\">research at the National Sleep Foundation on school start times<\/a>\u00a0or watch this <a href=\"https:\/\/www.ted.com\/talks\/wendy_troxel_why_school_should_start_later_for_teens\/transcript?language=en\">TED talk by Wendy Troxel: &#8220;Why Schools Should Start Later for Teens&#8221;<\/a>.<\/p>\n<\/div>\n<div class=\"textbox key-takeaways\">\n<h3>glossary<\/h3>\n<div class=\"titlepage\">\n<dl>\n<dt>amygdala:<\/dt>\n<dd>part of the limbic system in the brain, which is involved with emotions and emotional responses and is particularly active during puberty<\/dd>\n<dt>dopamine:<\/dt>\n<dd>a neurotransmitter in the brain that plays a role in pleasure and the reward system; increases in the limbic system and later in the prefrontal cortex during adolescence<\/dd>\n<dt>frontal lobes:<\/dt>\n<dd>the parts of the brain involved in impulse control, planning, and higher order thinking; still developing in adolescence<\/dd>\n<dt>limbic system:<\/dt>\n<dd>structures in the brain (including the amygdala) that involve processing emotional experience and social information and determining rewards and punishments; develops years before the prefrontal cortex<\/dd>\n<dt>melatonin:<\/dt>\n<dd>sleep hormone whose levels rise later at night and decrease later in the morning for teens, compared to children and adults<\/dd>\n<dt>myelination:<\/dt>\n<dd>insulation of neurons&#8217; axons with fatty substance (myelin sheath) that helps speed up the processing of information; myelination starts to increase in the prefrontal cortex during adolescence<\/dd>\n<dt>prefrontal cortex:<\/dt>\n<dd>part of the frontal lobes, involved with decision making, cognitive control, and other higher order functions; prefrontal cortex develops further during adolescence<\/dd>\n<dt>serotonin:<\/dt>\n<dd>&#8220;calming chemical,&#8221; a neurotransmitter in the brain involved with the regulation of mood and behavior; serotonin levels increase in the limbic system during adolescence<\/dd>\n<dt>synaptic pruning:<\/dt>\n<dd>connections in the brain that are not used much are lost so that other connections can be strengthened; this pruning happens with prefrontal cortex connections in adolescence<\/dd>\n<\/dl>\n<\/div>\n<\/div>\n\n\t\t\t <section class=\"citations-section\" role=\"contentinfo\">\n\t\t\t <h3>Candela Citations<\/h3>\n\t\t\t\t\t <div>\n\t\t\t\t\t\t <div id=\"citation-list-2982\">\n\t\t\t\t\t\t\t <div class=\"licensing\"><div class=\"license-attribution-dropdown-subheading\">CC licensed content, Original<\/div><ul class=\"citation-list\"><li>Brain Development During Adolescence modification, adaptation, and original content. <strong>Authored by<\/strong>: Tera Jones for Lumen Learning. <strong>Provided by<\/strong>: Lumen Learning. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/\">CC BY-SA: Attribution-ShareAlike<\/a><\/em><\/li><\/ul><div class=\"license-attribution-dropdown-subheading\">CC licensed content, Shared previously<\/div><ul class=\"citation-list\"><li>Adolescence. <strong>Provided by<\/strong>: Wikipedia. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"https:\/\/en.wikipedia.org\/wiki\/Adolescence\">https:\/\/en.wikipedia.org\/wiki\/Adolescence<\/a>. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/\">CC BY-SA: Attribution-ShareAlike<\/a><\/em><\/li><li>Stages of Development. <strong>Provided by<\/strong>: OpenStax College. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"http:\/\/cnx.org\/contents\/4abf04bf-93a0-45c3-9cbc-2cefd46e68cc@4.100:1\/Psychology\">http:\/\/cnx.org\/contents\/4abf04bf-93a0-45c3-9cbc-2cefd46e68cc@4.100:1\/Psychology<\/a>. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY: Attribution<\/a><\/em>. <strong>License Terms<\/strong>: Download for free at http:\/\/cnx.org\/contents\/02040312-72c8-441e-a685-20e9333f3e1d@10.1.<\/li><li>Adolescent Development. <strong>Authored by<\/strong>: Jennifer Lansford  . <strong>Provided by<\/strong>: Duke University. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"http:\/\/nobaproject.com\/modules\/adolescent-development?r=LDE2MjU3\">http:\/\/nobaproject.com\/modules\/adolescent-development?r=LDE2MjU3<\/a>. <strong>Project<\/strong>: The Noba Project. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/4.0\/\">CC BY-NC-SA: Attribution-NonCommercial-ShareAlike<\/a><\/em><\/li><\/ul><div class=\"license-attribution-dropdown-subheading\">All rights reserved content<\/div><ul class=\"citation-list\"><li>The Teenage Brain Explained. <strong>Provided by<\/strong>: SciShow. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"https:\/\/www.youtube.com\/watch?v=hiduiTq1ei8&#038;feature=youtu.be\">https:\/\/www.youtube.com\/watch?v=hiduiTq1ei8&#038;feature=youtu.be<\/a>. <strong>License<\/strong>: <em>Other<\/em>. <strong>License Terms<\/strong>: Standard YouTube License<\/li><li>Brain changes during adolescence | Behavior | MCAT. <strong>Provided by<\/strong>: Khan Academy. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"https:\/\/www.youtube.com\/watch?v=5Fa8U6BkhNo&#038;feature=youtu.be\">https:\/\/www.youtube.com\/watch?v=5Fa8U6BkhNo&#038;feature=youtu.be<\/a>. <strong>License<\/strong>: <em>Other<\/em>. <strong>License Terms<\/strong>: Standard YouTube License<\/li><\/ul><div class=\"license-attribution-dropdown-subheading\">Public domain content<\/div><ul class=\"citation-list\"><li>The Teen Brain: 6 Things to Know. <strong>Provided by<\/strong>: National Institute of Mental Health. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"https:\/\/www.nimh.nih.gov\/health\/publications\/the-teen-brain-6-things-to-know\/index.shtml#pub4\">https:\/\/www.nimh.nih.gov\/health\/publications\/the-teen-brain-6-things-to-know\/index.shtml#pub4<\/a>. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/about\/pdm\">Public Domain: No Known Copyright<\/a><\/em><\/li><\/ul><\/div>\n\t\t\t\t\t\t <\/div>\n\t\t\t\t\t <\/div>\n\t\t\t <\/section><hr class=\"before-footnotes clear\" \/><div class=\"footnotes\"><ol><li id=\"footnote-2982-1\">Romeo, R.D. (2013). The teenage brain: The stress response and the adolescent brain. Current Directions in Psychological Science, 22 (2), 140-145. <a href=\"#return-footnote-2982-1\" class=\"return-footnote\" aria-label=\"Return to footnote 1\">&crarr;<\/a><\/li><li id=\"footnote-2982-2\">Hartley, C.A. &amp; Somerville, L.H. (2015). The neuroscience of adolescent decision-making. Current Opinion in Behavioral Sciences, 5, 108-115. <a href=\"#return-footnote-2982-2\" class=\"return-footnote\" aria-label=\"Return to footnote 2\">&crarr;<\/a><\/li><li id=\"footnote-2982-3\">Steinberg, L. (2013). Adolescence (10th ed.). New York, NY: McGraw-Hill. <a href=\"#return-footnote-2982-3\" class=\"return-footnote\" aria-label=\"Return to footnote 3\">&crarr;<\/a><\/li><li id=\"footnote-2982-4\">Steinberg, L. (2008) A social neuroscience perspective on adolescent risk-taking. Developmental Review, 28:78-106. <a href=\"#return-footnote-2982-4\" class=\"return-footnote\" aria-label=\"Return to footnote 4\">&crarr;<\/a><\/li><li id=\"footnote-2982-5\">National Institute of Mental Health. The Teen Brain: 6 Things to Know. Retrieved from\u00a0https:\/\/www.nimh.nih.gov\/health\/publications\/the-teen-brain-6-things-to-know\/index.shtml#pub6. <a href=\"#return-footnote-2982-5\" class=\"return-footnote\" aria-label=\"Return to footnote 5\">&crarr;<\/a><\/li><\/ol><\/div>","protected":false},"author":29,"menu_order":4,"template":"","meta":{"_candela_citation":"[{\"type\":\"cc\",\"description\":\"Adolescence\",\"author\":\"\",\"organization\":\"Wikipedia\",\"url\":\"https:\/\/en.wikipedia.org\/wiki\/Adolescence\",\"project\":\"\",\"license\":\"cc-by-sa\",\"license_terms\":\"\"},{\"type\":\"original\",\"description\":\"Brain Development During Adolescence modification, adaptation, and original content\",\"author\":\"Tera Jones for Lumen Learning\",\"organization\":\"Lumen Learning\",\"url\":\"\",\"project\":\"\",\"license\":\"cc-by-sa\",\"license_terms\":\"\"},{\"type\":\"cc\",\"description\":\"Stages of Development\",\"author\":\"\",\"organization\":\"OpenStax College\",\"url\":\"http:\/\/cnx.org\/contents\/4abf04bf-93a0-45c3-9cbc-2cefd46e68cc@4.100:1\/Psychology\",\"project\":\"\",\"license\":\"cc-by\",\"license_terms\":\"Download for free at http:\/\/cnx.org\/contents\/02040312-72c8-441e-a685-20e9333f3e1d@10.1.\"},{\"type\":\"cc\",\"description\":\"Adolescent Development\",\"author\":\"Jennifer Lansford  \",\"organization\":\"Duke University\",\"url\":\"http:\/\/nobaproject.com\/modules\/adolescent-development?r=LDE2MjU3\",\"project\":\"The Noba Project\",\"license\":\"cc-by-nc-sa\",\"license_terms\":\"\"},{\"type\":\"copyrighted_video\",\"description\":\"The Teenage Brain Explained\",\"author\":\"\",\"organization\":\"SciShow\",\"url\":\"https:\/\/www.youtube.com\/watch?v=hiduiTq1ei8&feature=youtu.be\",\"project\":\"\",\"license\":\"other\",\"license_terms\":\"Standard YouTube License\"},{\"type\":\"copyrighted_video\",\"description\":\"Brain changes during adolescence | Behavior | MCAT\",\"author\":\"\",\"organization\":\"Khan Academy\",\"url\":\"https:\/\/www.youtube.com\/watch?v=5Fa8U6BkhNo&feature=youtu.be\",\"project\":\"\",\"license\":\"other\",\"license_terms\":\"Standard YouTube License\"},{\"type\":\"pd\",\"description\":\"The Teen Brain: 6 Things to Know\",\"author\":\"\",\"organization\":\"National Institute of Mental Health\",\"url\":\"https:\/\/www.nimh.nih.gov\/health\/publications\/the-teen-brain-6-things-to-know\/index.shtml#pub4\",\"project\":\"\",\"license\":\"pd\",\"license_terms\":\"\"}]","CANDELA_OUTCOMES_GUID":"ec7efca6-eae9-434c-a65a-690a40dfd645, a543b502-3c3b-447f-ab26-7d2d9de179f0","pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[],"license":[],"class_list":["post-2982","chapter","type-chapter","status-publish","hentry"],"part":308,"_links":{"self":[{"href":"https:\/\/courses.lumenlearning.com\/wm-lifespandevelopment\/wp-json\/pressbooks\/v2\/chapters\/2982","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/courses.lumenlearning.com\/wm-lifespandevelopment\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/courses.lumenlearning.com\/wm-lifespandevelopment\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/wm-lifespandevelopment\/wp-json\/wp\/v2\/users\/29"}],"version-history":[{"count":57,"href":"https:\/\/courses.lumenlearning.com\/wm-lifespandevelopment\/wp-json\/pressbooks\/v2\/chapters\/2982\/revisions"}],"predecessor-version":[{"id":7805,"href":"https:\/\/courses.lumenlearning.com\/wm-lifespandevelopment\/wp-json\/pressbooks\/v2\/chapters\/2982\/revisions\/7805"}],"part":[{"href":"https:\/\/courses.lumenlearning.com\/wm-lifespandevelopment\/wp-json\/pressbooks\/v2\/parts\/308"}],"metadata":[{"href":"https:\/\/courses.lumenlearning.com\/wm-lifespandevelopment\/wp-json\/pressbooks\/v2\/chapters\/2982\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/courses.lumenlearning.com\/wm-lifespandevelopment\/wp-json\/wp\/v2\/media?parent=2982"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/wm-lifespandevelopment\/wp-json\/pressbooks\/v2\/chapter-type?post=2982"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/wm-lifespandevelopment\/wp-json\/wp\/v2\/contributor?post=2982"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/wm-lifespandevelopment\/wp-json\/wp\/v2\/license?post=2982"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}