The Amygdala and the Prefrontal Cortex

We’re going to compare two parts of the brain: The Amygdala and the Prefrontal Cortex. The amygdala gets a lot of press (though you might not know it!). it’s the oldest part of our brain evolutionarily speaking, and it governs our emotional responses and most famously issues that ‘Fight or Flight’ response (which nowadays is also understood to have a ‘Freeze’ option as well). Some people call it our first brain, some people call it our lizard brain, some people call it ‘my relic of self-preservation’. Whatever you call it, the amygdala is the most primitive part of your brain.

 

The prefrontal cortex is the newest part, evolutionarily speaking. It is responsible for decision making, moderating our behavior, and orchestrating thoughts and actions in accordance with internal goals. The prefrontal cortex is where we manifest our personality.

Now, let’s call something important into question: where is my ‘self’? What part(s) of my brain is ‘me’?

This question is an entire field of study in philosophy and neuroscience. There is no clear answer. We see a neural basis of ‘self’ in many parts of the brain, through morality, embodiment, memory, and more.

There’s even neurobiological evidence supporting a spectrum of collectivistic vs. individualistic sense of identity. You can listen to a neuroscientist and two presenters debate our sense of/location of the self in the RadioLab episode entitled ‘Blame’ http://www.radiolab.org/story/317421-blame/.

 

It’s generally agreed upon that “I” am some combination of these parts. The amygdala and the prefrontal cortex wonderfully represent two contrasting elements. You might think of them as different sides of a spectrum.

Every time we experience an event, whether a small sensation of wind on our neck or a life-altering break-up, these parts of our brain compete. Our amygdala sends us base-level emotional responses: “Pain!” “Fear!” “Sad!” “Safe!”

And our prefrontal cortex moderates these signals with rational thought: “Fear can mean opportunity!” “What does this pain mean?” “Sadness. Yes, I’m feeling sad because…”

 

We, the sum of our many parts, contain conscious control. We can choose what parts of our self to identify with. We can be more of our prefrontal cortex.

 

Most of the time, our amygdala, our emotional autopilot, is firing signals without our conscious mind being aware of what’s happening.

But, like our breath, we can draw our attention to the effects and change them (you can hold your breath – you can increase your lung capacity – you can exercise your diaphragm, etc.). In the same way, we can ‘work out’ the connections between our prefrontal cortex and our amygdala to get closer to who we want to be. We can habituate thoughts and behaviours for when these parts of our brain compete, and we can choose to identify with one part more than the other. In fact, by practicing more conscious attention to our thoughts/feelings as sensations, we can literally change the structure of our brain, enhance our capacity to self-regulate, or even delay cognitive impairment like Alzheimer’s.

 

Let’s take an example. Think about a time when you were startled by someone. Say, you thought you were all alone, and you turned the corner and saw your roommate there and you jumped out of your shoes. That ‘jumping’ feeling is the startle reflex… and it’s controlled by the amygdala. Next, you might have laughed a little bit, or even said “Holy cow! You scared me!” Both of those responses are from your prefrontal cortex. In a millisecond, you trumped the startle reflex, evaluated the surroundings, accessed a memory of your roommate and what s/he looks like, associated that memory with a feeling of safety, channeled that feeling of safety into your amygdala, and calmed yourself down. If you hadn’t – you likely would have run out of the room, or run towards your roommate in an attempt to kill him/her. That millisecond of ‘tug-of-war’ between your amygdala and prefrontal cortex is your ability to choose–to define yourself, your actions and decide who you will be.

Let’s say you turned that corner and there was a robber there instead of your roommate. You wouldn’t feel your prefrontal cortex having so much control. Instead you might jump, scream, and start running. Your heart would be beating, your hands would get sweaty and all of your senses would likely go into overdrive. But wait… you might say… how did I know what to do if my amygdala is super-primitive? I immediately thought to call the police, but my primal brain wouldn’t know anything about phones or police.

Herein lies the crucial point: it’s not that one side ‘wins’ – both are working strongly in tandem – and even though the amygdala might have you seeing red, you’re still accessing memories, associations, habits, beliefs, cultural biases, and acting with your prefrontal cortex. Your rational, thinking self is still active, even if it has been toned down a little.

 

Now, here is the key:

We can train our brains to amplify the signal from our rational “self” and turn down the signal from our primitive, more emotional “self”. Put another way, we can increase the strength of the pathways from our prefrontal cortex, and decrease the strength of the pathways from our amygdala.

 

It’s not magic, it’s neuroplasticity. In this case, we’re talking about ‘Emotion Regulation’ which is not about turning off our emotions. It’s about learning how to channel those emotions in ways that are useful for our higher-processing selves. This is the very foundation of Forgiveness. Some may call it Mindfulness.

In working through the forgiveness model, we’re learning how to notice and appreciate our initial emotional reaction (the amygdala’s screaming) while strengthening the pathways from the prefrontal cortex, allowing our views and responses to any particular event to be more mindful .

When we stumble on our path to forgive, the amygdala has given us a fresh glass of primal tonic – it has remembered that we weren’t safe, that something was ‘bad,’ that we were in pain and that pain is ‘no good!’, or that the world outside is ‘wrong’. The amygdala offers its glass during the event, and even each time we recall it. And, each time re-story the event, coming back to our amygdala with a different framing, we strengthen the pathways that run from our prefrontal cortex to our amygdala. We understand that if and how much we wish to drink from that glass is our choice.

Eventually, as we change how our amygdala and prefrontal cortex interact, we can habitually give more power to our thinking, rational brain. We can hand over our responses and perceptions to our sense of self and who we want to be. In a 2012 study it was found that masters of certain meditation practices could largely control the startle response – a testament to the robustness of the passageways (even back-alley ones!) between their brain centers.

 

 

By forgiving, we train ourselves to hear the cries of our amygdala with a peaceful internal ear, saying “I hear you. You feel ____. Here is how I wish to proceed…” The more we practice mindfulness around our emotional responses, the more possibilities we open to choose who we are and how we think. We gain greater control in the future around our emotional states.

For more on mindfulness, visit http://greatergood.berkeley.edu/topic/mindfulness/definition.

References:

  1. Miller EK, Freedman DJ, Wallis JD (August 2002). “The prefrontal cortex: categories, concepts and cognition”
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  3. Botzung, A., Denkova, E., Ciuciu, P., Scheiber, C., & Manning, L. (2008). The neural bases of the constructive nature of autobiographical memories studied with a self-paced fMRI design.
  4. Moll, J., de Oliveira-Souza, R., Garrido, G. J., Bramati, I. E., Caparelli-Daquer, E. M. A., Paiva, M., et al. (2007). The self as a moral agent: Link-ling the neural bases of social agency and moral sensitivity.
  5. Chiao, J. Y., Harada, T., Komeda, H., Li, Z., Mano, Y., Saito, D., et al. (2009). Neural Basis of Individualistic and Collectivistic Views of Self. Human Brain Mapping
  6. Tang, Yi-Yuan; Posner, Michael I. (September 5, 2012). “Special issue on mindfulness neuroscience”. Social Cognitive and Affective Neuroscience
  7. http://www.ncbi.nlm.nih.gov/pubmed/22506498