Emotion in the Brain

Emotion in the Brain

The major brain regions that support emotional processing include the limbic system – particularly the hippocampus, amygdala, and hypothalamus – and the prefrontal cortex, anterior cingulate cortex (ACC), nucleus accumbens, and insula. Technical note: there are two hippocampi, one in each hemisphere of the brain; the same for the two amygdalae, ACCs, and insulae. Following common practice, we’ll mainly use the singular form.

By the way, as an interesting evolutionary detail, the limbic system seems to have evolved from the olfactory (scent) neural circuitry in the brain developed by our ancient mammal ancestors, living around 180 million years ago. They seem to have used their advanced sense of smell to hunt at night, while those cold-blooded reptiles were snoozing – and easier prey.

The conscious experience of emotion is just the top story – the penthouse floor – resting on many layers of neurological activity, both the firing of very complex and intertwining neural circuits and the tidal flows of neurotransmitters and hormones such as dopamine, serotonin, and oxytocin. Here’s a brief summary of each of these brain regions and its apparent role in emotion:

  • Hippocampus – This vaguely sea-horse shaped region helps store the contexts, especially visual-spatial ones, for important experiences, such as the smell of a predator . . . or the look of an angry parent. This region is necessary for forming personal memories of events, and is unfortunately damaged over time by the cortisol released by chronic stress (especially, high or even traumatic levels of stress).
  • Amygdala – Connected to the hippocampus by the neural equivalent of a four-lane superhighway, this small, almond-shaped region is particularly involved in the processing of information about threats. The subjective awareness of threat comesfrom the feeling tone of experience when it is unpleasant (distinct from pleasant or neutral). When it perceives a threat – whet her an external stimulus like a car running a red light or an internal one, such as suddenly recalling an impending deadline – the amygdala sends a jolt of alarm to the hypothalamus and other brain regions. It also triggers the ventral tegmentum, in the brain stem, to send dopamine to the nucleus accumbens (and other brain regions) in order to sensitize them all to the “red alert” information now streaming through the brain as a whole.
  • Hypothalamus – This is a major switchboard of the brain, involved in the regulation of basic bodily drives such as thirst and hunger. When it gets a “Yikes!” signal from the amygdala, it tells the pituitary gland to tell the adrenals to start release epinephrine and other stress hormones, to get the body ready for immediate fight-or-flight action. But keep in mind that this activation occurs not just when a lionjumps out of the bushes, but chronically, in rush-hour traffic and multi-tasking, and in response to internal mental events such as pain or anger. (For more on the stress response – and what you can do about it – see the Wise Brain Bulletins, Volume 1, #5 and #6.)
  • Prefrontal cortex (PFC) – If you whack your self on the forehead, the mini-shock waves reverberate through the PFC, which is “pre” because it is in front of the frontal cortex. The PFC is centrally involved in anticipating things, making plans, organizing action, monitoring results, changing plans, and settling conflicts between different goals: these are called the “executive functions,” and if the brain is one big village, the PFC is its mayor. Where emotion is concerned, the PFC helps foresee the emotional rewards (or penalties) of different courses of action. The PFC also inhibits emotional reactions; many more nerve fibers head down from the PFC to the limbic circuitry than in the other direction. The left PFC plays a special role in controlling negative affect and aggression: stroke victims whose left PFC is damaged tend to become more irritable, distraught, and hostile (the same happened for the unfortunate and famous Phineas Gage, the engineer who suffered an iron bar through his forehead in a mining explosion). On the other hand, differential activation of the left PFC is associatedwith positive emotions – and years of meditation practice!
  • Anterior cingulate cortex (ACC) – This sits in the middle of the brain, centrally  located for communication with the PFC and the limbic system. It monitors conflicts between different objects of attention – Should I notice the bananas in this tree or that snake slithering toward me? Should I listen to my partner or focus on this TV show? – and flags those for resolution by the frontal lobes. Therefore, it lights up when we attend to emotionally relevant stimuli, or sustain our attention to important feelings – inside ourselves and other people – in the face of competing stimuli (e.g., trying to get a sense for what’s really bugging a family member underneath a rambling story and other verbiage).
  • Nucleus accumbens – In conditions of emotional arousal – especially fear-related – the accumbens receives a major wake-up call of dopamine from the tegmentum, which sensitizes it to information coming from the amygdala and other regions. Consequently, the accumbens sends more intense signals to the pallidum, a relay station for the motor systems, which results in heightened behavioral activity. This system works for both negative and positive feelings. For example, the accumbens lights up when a person with an addiction sees the object of his or her craving.
  • Insula – Deeply involved in interoception – the sensing of the internal state of the body (e.g., gut feelings, internal sensations of breathing, nausea) – the insula lets you know about the deeper layers of your emotional life. And it is key to sensing theprimary emotions in others, suchas fear of pain, or disgust.

 



Dr. Ramani Durvasula is a licensed clinical psychologist, author, and expert on the impact of toxic narcissism. She is a Professor of Psychology at California State University, Los Angeles, and also a Visiting Professor at the University of Johannesburg.

The focus of Dr. Ramani’s clinical, academic, and consultative work is the etiology and impact of narcissism and high-conflict, entitled, antagonistic personality styles on human relationships, mental health, and societal expectations. She has spoken on these issues to clinicians, educators, and researchers around the world.

She is the author of Should I Stay or Should I Go: Surviving a Relationship With a Narcissist, and Don't You Know Who I Am? How to Stay Sane in an Era of Narcissism, Entitlement, and Incivility. Her work has been featured at SxSW, TEDx, and on a wide range of media platforms including Red Table Talk, the Today Show, Oxygen, Investigation Discovery, and Bravo, and she is a featured expert on the digital media mental health platform MedCircle. Dr. Durvasula’s research on personality disorders has been funded by the National Institutes of Health and she is a Consulting Editor of the scientific journal Behavioral Medicine.

Dr. Stephen Porges is a Distinguished University Scientist at Indiana University, Professor of Psychiatry at the University of North Carolina, and Professor Emeritus at both the University of Illinois at Chicago and the University of Maryland. He is a former president of the Society for Psychophysiological Research and has been president of the Federation of Behavioral, Psychological, and Cognitive Sciences, which represents approximately twenty-thousand biobehavioral scientists. He’s led a number of other organizations and received a wide variety of professional awards.

In 1994 he proposed the Polyvagal Theory, a theory that links the evolution of the mammalian autonomic nervous system to social behavior and emphasizes the importance of physiological states in the expression of behavioral problems and psychiatric disorders. The theory is leading to innovative treatments based on insights into the mechanisms mediating symptoms observed in several behavioral, psychiatric, and physical disorders, and has had a major impact on the field of psychology.

Dr. Porges has published more than 300 peer-reviewed papers across a wide array of disciplines. He’s also the author of several books including The Polyvagal Theory: Neurophysiological foundations of Emotions, Attachment, Communication, and Self-regulation.

Dr. Bruce Perry is the Principal of the Neurosequential Network, Senior Fellow of The ChildTrauma Academy, and a Professor (Adjunct) in the Departments of Psychiatry and Behavioral Sciences at the Feinberg School of Medicine at Northwestern University in Chicago and the School of Allied Health at La Trobe University in Melbourne, Australia. From 1993 to 2001 he was the Thomas S. Trammell Research Professor of Psychiatry at Baylor College of Medicine and chief of psychiatry at Texas Children's Hospital.

He’s one of the world’s leading experts on the impact of trauma in childhood, and his work on the impact of abuse, neglect, and trauma on the developing brain has impacted clinical practice, programs, and policy across the world. His work has been instrumental in describing how traumatic events in childhood change the biology of the brain.

Dr. Perry's most recent book, What Happened to You? Conversations on Trauma, Resilience, and Healing, co-authored with Oprah Winfrey, was released earlier this year. Dr. Perry is also the author, with Maia Szalavitz, of The Boy Who Was Raised As A Dog, a bestselling book based on his work with maltreated children, and Born For Love: Why Empathy is Essential and Endangered. Additionally, he’s authored more than 300 journal articles and book chapters and has been the recipient of a variety of professional awards.

Dr. Allison Briscoe-Smith is a child clinical psychologist who specializes in trauma and issues of race. She earned her undergraduate degree from Harvard and then received her Ph.D. in clinical psychology from the University of California, Berkeley. She performed postdoctoral work at the University of California San Francisco/San Francisco General Hospital. She has combined her love of teaching and advocacy by serving as a professor and by directing mental health programs for children experiencing trauma, homelessness, or foster care.

Dr. Briscoe-Smith is also a senior fellow of Berkeley’s Greater Good Science Center and is both a professor and the Director of Diversity, Equity, and Inclusion at the Wright Institute. She provides consultation and training to nonprofits and schools on how to support trauma-informed practices and cultural accountability.

Sharon Salzberg is a world-renowned teacher and New York Times bestselling author. She is widely considered one of the most influential individuals in bringing mindfulness practices to the West, and co-founded the Insight Meditation Society in Barre, Massachusetts alongside Jack Kornfield and Joseph Goldstein. Sharon has been a student of Dipa Ma, Anagarika Munindra, and Sayadaw U Pandita alongside other masters.

Sharon has authored 10 books, and is the host of the fantastic Metta Hour podcast. She was a contributing editor of Oprah’s O Magazine, had her work featured in Time and on NPR, and contributed to panels alongside the Dalai Lama.

Get the Just One Thing
Weekly Newsletter

A simple practice each week that will bring you more joy, more fulfilling relationships, and more peace of mind and heart.

  • This field is for validation purposes and should be left unchanged.

You can unsubscribe at any time and your email address will never be shared.