The Triple Decker Brain - Dr. Linda Acredolo

NiaSadeMomma · #1 (**permalink**) 03-23-2005, 06:56 PM

Hello everyone,

Dr. Linda Acredolo wrote something very informative in our newsletter that I think you signing mommies will enjoy reading!

The Brains Behind Our Emotions
By Linda Acredolo, PhD

The love we feel for our children is magical, not mechanical. It seems to well up from deep inside, melting our hearts an making us smile. But how does all this happen? What exactly is going on when we cuddle with our children, body to body and heart to heart? It may surprise you to learn that a large part of what is going on is actually “brain to brain.” What’s more, it’s not just two brains in sync with each other; it’s more like three brains each, for a total of six!

The Triple-Decker Brain

Thomas Lewis, Fari Amini, and Richard Lannon, three psychiatry professors at the University of California, San Francisco, School of Medicine, provide a wonderful description of the relation between our multiple brains and our experiences of love in their fascinating book, A General Theory of Love. In it they explain how human emotions are really the result of incredibly rapid and complex cross-talk among three separate “mini-brains,” each one a separate product of evolution.

In the Beginning: The Reptilian Brain.
This is the name given to the most basic and historically earliest level. Located at the top of the spinal cord, the reptilian brain doesn’t generate any complex emotions beyond the very important “fight or flight” responses that enable us to react with lightening speed to danger. For example, when your child jumps out at you from behind a door, shouting “Boo!” the images from your eye travel immediately to the primitive reptilian brain and set in motion changes in very basic bodily functions (in heart rate, breathing, muscle tone, etc.) that enable you to jump 3 feet in the air!
Fortunately, unlike reptiles, our reaction doesn’t stop there. Because of the development later in evolution of the other two levels of the triple-decker brain, we also react with specific “feelings” (most likely fear, followed by relief, followed by irritation) and specific “thoughts” (for example, “That kid will be the death of me!”).

With Fur Came Feelings: The Limbic Brain.
The appearance of mammals on the evolutionary scene was the advancement that ushered in emotions--or what we more colloquially term “feelings.” That doesn’t mean that all mammals are consciously aware of these feelings-- a gift granted humans by the further development of layer #3, the cerebral cortex. It does mean, however, that much of mammalian behavior is motivated by internal states that linger over time and get them in and out of much more complex interactions with their peers and offspring (not just predators). How does the limbic brain accomplish all this? Essentially by coordinating the activities of any part of the body even vaguely involved in emotions. This includes the various biological functions controlled by the reptilian brain as well as any emotion-relevant thoughts or perceptions flowing down the pipeline from the top layer, the cerebral cortex. It also includes all hormones involved in emotions--such as stress and sex hormones--via one of its own structures, the hypothalamus. The limbic brain, and especially its main component called the “amygdala,” is like a master switchboard operator, receiving phone calls from lines coming into the board from various parts of the body and then figuring out what lines these calls should be connected to on their way out. For example, when 3-year-old Johnny suddenly runs into the street, it’s Mom’s amygdale that senses the danger and then triggers the adrenalin rush that fuels her sudden intake of breath, her accelerated heart beat, and her mad dash to save him from harm. Without the amygdala, in other words, little Johnny might not be here--and chances are good that, given the powers of natural selection, neither would we!

And Then There Were Three: The Thinking Brain.
The human cerebral cortex is the latest evolutionary comer. This gray and profoundly wrinkled sheet, scrunched up right under our skulls, is what enables humans to think, plan, remember, and talk--all activities that involve some kind of emotion nine times out often. Looking at the newborn baby in our arms, we not only feel love welling up in our throats, but also think about how much we love her, sing her praises to others, and plan for her future.

And where does the particular lilt to our voice come from when we whisper “I love you!” in her ear? Straight up from the limbic brain to the speech centers in the cerebral cortex. In other words, we speak because we have a cortex, but we speak of love because we also have a limbic brain. Teamwork extraordinaire! So, the next time you and your child share a sweet moment, remember to give credit where credit is due: to both your and your child’s “Triple-Decker Brain.”

The authors of Baby Signs® are moms first and child-psychologist second

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I will be sharing with you signing mommies topics that they write in our newsletter, that I hope somehow will give you added information.

Have a wonderful week! Happy Signing!

A Blessed Happy Easter to ALL OF YOU and your family!

Wendy~ · #2 (**permalink**) 03-24-2005, 06:29 AM

Thank you!