Day 127 of 365 - Mind, Body, Emotions - Part 1
I learned another new word this week. It is abstruse, meaning difficult to comprehend. Today, as a follow up to yesterday's post, I'm going to attempt to describe some of the evolutionary functions of our human brain and nervous system, so we can better understand the connection between mind, body and emotions. I realize this can be an abstruse topic.
Information for this topic comes from the work of Dr. Dan Siegel, psychiatrist, and his model of the brain. Further information comes from Dr. Stephen Porges, neuropsychiatry researcher and developer of the polyvagal theory. The what? Bear with me and we'll get to it later.
When we think of the brain, initially we probably think of the large squiggly walnut shaped surface that is commonly portrayed. This is actually the more recent evolution of the brain, called the cortex. We might be familiar with the concept of different areas of the brain being mapped according to our senses, like sight, sound, taste and so on. The frontal part of the brain is where thought associations occur, and the prefrontal area a bit below it, integrates input from the social world, the body and other parts of the brain. It is the most recent evolution of the cortex.
Before that, the mammalian region of the brain developed. It is the midbrain and where our emotional center, or limbic system resides. This area creates emotions in conjunction with the body. It assigns meaning or significance to input and is also connected to the memory area of the brain, the hippocampus. Our attachment experiences are also mediated by the limbic system.
And, before that, we operated primarily from our reptilian brain, which is the brainstem. It takes in information from the body and has the regions which create the fight/flight or faint/freeze responses when we feel threatened. It causes a reactive response primarily around survival and safety.
Those above three areas are components of the central nervous system. Then, deriving from the brainstem is the peripheral nervous system. The cranial and spinal nerves are distributed for sensory and body awareness. Then there is also the autonomic nervous system, which takes care of the body's internal environment. The sympathetic nervous system takes care of survival responses and the parasympathetic nervous system restores balance after a disruption.
The vagus nerve, Cranial Nerve 10, is the largest and longest nerve in the body, originating in the brainstem and feeding down through the neck, thorax and abdomen. It is part of both the sensory and the autonomic nervous systems.
Stephen Porges identified that the vagus nerve performs different roles in a hierarchical manner, his polyvagal theory. The dorsal vagus nerve descends below the diaphragm and is activated in times of overwhelming distress to initiate self-preservation responses like shutting down. The ventral vagus nerve runs from the brain to the heart and maintains body functions in times of low stress. It also engages functions for social interaction, like facial expression and tone of voice.
The understanding of how the body reacts to challenges is based on the evolution of our autonomic nervous system. The circuits function in a hierarchy. The older circuits, to brainstem and midbrain are the circuits of defense and are mainly linked to the area below the diaphragm and are adaptive. These are reflexive responses, made by the body to protect itself. We feel the bodily response but we don't always know what it reacted to. The bodily reactions trigger our higher brain that we need to do something.
The ventral vagus nerve, running from brainstem to heart, is a circuit of social interaction, and is linked to muscles of the face and head. It regulates the muscles of listening, expression and gesture and enables our body to be in a state that supports health, growth and restoration. When that system doesn't work, we see the ventral vagus expression of the lower level, more protective emotional responses. These are active defenses such as anger, rage and irritation (fight responses) or panic, anxiety and fear (flight responses). These are not inherently 'bad' but our mind may interpret them as so. Activation of the dorsal vagal circuits, below the diaphragm, is a more biologically passive defense, like collapsing or freezing. Once we recognize how our reflexive bodily responses are protecting us, we can shift our understanding of our behavior.
Learning to pay attention to our bodily reactions or cues can point us to an associative memory, which can help us at the higher brain level to understand an automatic emotional response, and more clearly see which predominant underlying feeling is part of the reaction. This is where riding out that 90 seconds of bodily reaction comes in, being aware first of the reflexive bodily response and then the higher brain emotional understanding. In the next post, we'll explore this some more.
Information for this topic comes from the work of Dr. Dan Siegel, psychiatrist, and his model of the brain. Further information comes from Dr. Stephen Porges, neuropsychiatry researcher and developer of the polyvagal theory. The what? Bear with me and we'll get to it later.
When we think of the brain, initially we probably think of the large squiggly walnut shaped surface that is commonly portrayed. This is actually the more recent evolution of the brain, called the cortex. We might be familiar with the concept of different areas of the brain being mapped according to our senses, like sight, sound, taste and so on. The frontal part of the brain is where thought associations occur, and the prefrontal area a bit below it, integrates input from the social world, the body and other parts of the brain. It is the most recent evolution of the cortex.
Before that, the mammalian region of the brain developed. It is the midbrain and where our emotional center, or limbic system resides. This area creates emotions in conjunction with the body. It assigns meaning or significance to input and is also connected to the memory area of the brain, the hippocampus. Our attachment experiences are also mediated by the limbic system.
And, before that, we operated primarily from our reptilian brain, which is the brainstem. It takes in information from the body and has the regions which create the fight/flight or faint/freeze responses when we feel threatened. It causes a reactive response primarily around survival and safety.
Those above three areas are components of the central nervous system. Then, deriving from the brainstem is the peripheral nervous system. The cranial and spinal nerves are distributed for sensory and body awareness. Then there is also the autonomic nervous system, which takes care of the body's internal environment. The sympathetic nervous system takes care of survival responses and the parasympathetic nervous system restores balance after a disruption.
The vagus nerve, Cranial Nerve 10, is the largest and longest nerve in the body, originating in the brainstem and feeding down through the neck, thorax and abdomen. It is part of both the sensory and the autonomic nervous systems.
Stephen Porges identified that the vagus nerve performs different roles in a hierarchical manner, his polyvagal theory. The dorsal vagus nerve descends below the diaphragm and is activated in times of overwhelming distress to initiate self-preservation responses like shutting down. The ventral vagus nerve runs from the brain to the heart and maintains body functions in times of low stress. It also engages functions for social interaction, like facial expression and tone of voice.
The understanding of how the body reacts to challenges is based on the evolution of our autonomic nervous system. The circuits function in a hierarchy. The older circuits, to brainstem and midbrain are the circuits of defense and are mainly linked to the area below the diaphragm and are adaptive. These are reflexive responses, made by the body to protect itself. We feel the bodily response but we don't always know what it reacted to. The bodily reactions trigger our higher brain that we need to do something.
The ventral vagus nerve, running from brainstem to heart, is a circuit of social interaction, and is linked to muscles of the face and head. It regulates the muscles of listening, expression and gesture and enables our body to be in a state that supports health, growth and restoration. When that system doesn't work, we see the ventral vagus expression of the lower level, more protective emotional responses. These are active defenses such as anger, rage and irritation (fight responses) or panic, anxiety and fear (flight responses). These are not inherently 'bad' but our mind may interpret them as so. Activation of the dorsal vagal circuits, below the diaphragm, is a more biologically passive defense, like collapsing or freezing. Once we recognize how our reflexive bodily responses are protecting us, we can shift our understanding of our behavior.
Learning to pay attention to our bodily reactions or cues can point us to an associative memory, which can help us at the higher brain level to understand an automatic emotional response, and more clearly see which predominant underlying feeling is part of the reaction. This is where riding out that 90 seconds of bodily reaction comes in, being aware first of the reflexive bodily response and then the higher brain emotional understanding. In the next post, we'll explore this some more.
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