Monday, 20 August 2012

Brain 1.4

Many marvel at the magnificence of the human brain and the unsurpassed cognitive ability that lies within.  It is true that our brains can accomplish great feats of reason, logic, problem-solving, and creativity, but all of that is the domain of the cortex - the higher functioning part of our brain.  If we look at the systems below the cortex, we can see that the design of our brains isn’t the greatest.

Our brains - all brains on planet Earth - developed pretty much the same way, beginning with a rudimentary organ that keeps us alive: the Brainstem

This brain organ keeps our heart beating, our lungs breathing, our temperature and blood pressure regulated, and all the other systems in our body functioning as they should to sustain life.  The Brainstem is about 300 million years old and all the little critters that moved around received one.  In modern computer operating system parlance, this would be “Brain 1.0”.

The problem was that over time some critters started eating other critters, so a way to sense danger and to ensure survival of self and species was needed - we needed to be able to distinguish between friend or foe.  Instead of redesigning the brain, nature added a new system that could take care of these more complex needs - the Limbic System - and it was plugged into the top of the Brainstem about 200 million years ago.

Within the Limbic System are organs that create the desire to mate, make offspring, sense, remember, and react to everything in our environment.  The Limbic system is our guardian - it helps us survive not only as a species, but as an individual by differentiating between those we can mate with and those who pose a danger to us.  This additional system saw our brains change from “Brain 1.0” to “Brain 1.2”.

But now that our world and our functionality was becoming more fine-tuned, we needed a way to move skillfully in it, and so the Cerebellum was plugged into the brainstem and Limbic system.

The Cerebellum [Latin for “small brain”] helps us move in a coordinated way by controlling our limbs and giving us practical motor skills.  This way we can move toward others of our kind for propagation and safety, and away from those who mean us harm.  This move saw us move to “Brain 1.3”.

Armed with these developing tools, our world became more and more complex as each critter competed to survive.  To navigate that complexity - and to survive as a species and as an individual - we needed more than the basics of a Brainstem-Limbic-Cerebellum system could provide us.  And so the Cortex developed - the realm of higher functioning in our brains.  But again, it was an addition to the existing system, not a complete overhaul.

The Cortex is comprised of different areas that control different aspects of our functioning; Visual, sensory, motor, prefrontal, speech control and interpretation, plus a great deal of area that can be used as memory storage.  It’s a complex organ that sets us apart from other creatures on the planet.  So, this addition saw us move to “Brain 1.4”.

As stated above, the problem is that as our brains developed, instead of a complete redesign at each stage, the new parts were added onto the old parts like Lego blocks.  This means that all the older parts of our brain can still function without the newer parts and that is a “good news - bad news” proposition.

The good news is that as we learn new skills, such as riding a bike; We can practice and develop the skill to ride a bike using our Cortex, then assign that skill to our Cerebellum so we no longer have to think about it - we simply hop on our bike and the Cerebellum takes over.

More good news is that this system helps keep us safe by speeding up our response to danger.  Our Cortex is a wonder of computing power, but - compared to the lower parts of our brain - it is slow.  To survive a sudden threat, we need speed that is unencumbered by the slow logical processes in our Cortex.

Within our Limbic System are a number of smaller organs that each have a particular job.  Three of the significant ones are;

  • Thalamus - relays sensory and motor signals and regulates consciousness, sleep, and alertness
  • Amygdala - performs the main role in the processing of memory and emotional reactions
  • Hippocampus - consolidates information from short-term memory to long-term memory
This system keeps us safe by monitoring our environment for danger and through other organs in the Limbic System will put us on high alert if is senses danger - and for speed, it’s connected directly to the Brainstem and Cerebellum.

When our body sends a signal up our Brainstem or through our vision or hearing, it first lands in the Limbic System.  The Amygdala immediately works with the Hippocampus to determine if this signal indicates danger by searching for memory of that same signal in the past.  If a memory matches that signal and is classified as a danger, the Amygdala triggers the release of a chemical soup that includes Cortisol [the “stress” hormone] and Norepinephrine [adrenalin] and gets the body ready for a “flight or flight” response.

What does this response look like?  Our bodies tense to get ready to run or fight for our lives - [this sometimes makes us feel weak, because groups of opposing muscles are pulling against each other]; Our heart rate increases to supply more oxygen to our muscles; Our blood pressure changes to meet the demands of our circulatory system; Our breathing rate increases to get more oxygen into our system; We may grow pale as blood is pulled deep into our bodies in case we are wounded; We may have an overwhelming need to “get out of here” or sometimes start feeling angry and aggressive as we prepare to fight for our lives depending on our nature.

This is a terrific safety system to keep us alive in dangerous situations.  Without it we would walk into traffic and pet snarling dogs.

The bad news is that because this system is designed to work on its own to make sure our response isn’t slowed down by having to consult our higher functioning brain, a fear response can cause us problems because in many cases it isn’t a real fear and our Cortex can’t stop it in time.  We end up having an “anxiety attack” without even knowing why we are feeling distress.  It would be nice to have all the systems integrated so the higher functioning parts of our brain is included in this safety system so we could consciously limit our fear responses, but it doesn’t look like “Brain 2.0” is on the horizon yet.

So, are we doomed to be ruled by a poorly designed brain system that isn’t rational and sometimes reacts to every day events with fear?

No.  There are many therapies that can address recurring anxiety problems; Our Limbic system was programmed to react to specific stimulus with fear, so we can reprogram it to recognize that many stimuli are not dangerous at all.

Therapy to reprogram our unreasonable fear responses takes courage and no small amount of effort, but until we are issued a “Brain 2.0”, we have to work with what we have.

Aaron D. McClelland, RPCc

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