What most of us
aren’t aware of is just how much of a slave we typically are to our biology –
and especially when it comes to neuroscience.
We have the
illusion of self-control. That is to say that we feel like we choose what we do
and we choose how we feel. If we’re angry, it’s because of some injustice –
we’ve thought about the situation and decided that anger is the correct
response.
If you’re happy, it’s because all is well with the world and you’re content.
We then take all
this information and decide what we want to do next and how we’re going to
perform at that activity.
But the reality is
that we are not in charge of our brains. Rather, our brains are in charge of
us. And they’re largely controlled by our bodies and our situations too. Unless
we understand the workings of our brain and we’re able to take conscious
control over the processes that dictate our moods, our motivations and more,
then we are destined to remain at the whim of certain chemicals – and
completely oblivious to that fact.
Okay, so let’s go deep right off the bat. Who are ‘you’? What makes you, you?
The answer is your
brain to a large extent. And your brain in turn is made up of billions of
neurons – small cells that have tendril-like extensions reaching out and into
the different corners of your skull. These neurons can be created, destroyed or
changed via our experiences and they represent all kinds of things including
memories, sights, smells, thoughts and ‘commands’ to move our body.
When an electrical
impulse moves through a neuron, this means it is ‘firing’ and thus we experience
whatever correlates with that firing. If you open up someone’s skull and use an
electrode to stimulate individual neurons, then one might make someone see a
point of red light, one might make someone move their arm and another might
make them remember their Mother.
These neurons are
all interconnected and the more often two neurons fire at once, the more
connected they become. Thus, when one neurons fires, it is likely that others
around it will fire depending on the strength of the firing (called an ‘action
potential), other activity in the area and the strength of the connection. Some
‘clusters’ of neurons form the major brain structures like the occipital lobe,
motor cortex or hippocampus which are responsible for particular behaviors.
Other neurons reach from one end of the brain all the way to the other!
Already you can
see how your brain is not always entirely under your control. If you see
something specific, then this will cause certain neurons to fire based on your
memories and understanding of that object. But it might also cause surrounding
neurons to fire, depending on the associations you’ve formed during that
life-time.
And when certain
neurons fire, they cause particular emotions. That’s because neurons
communicate across synapses – small gaps between the end of one neuron (the
axon – which is like a tail) and the dendrites (like arms) of another.
At the end of each
axon is the synaptic knob, which is filled with chemicals called
neurotransmitters, held inside ‘neuro vesicles’. When the synapse fires, it
causes these neurotransmitters to be released and that then alters the behavior of the transmission and the surrounding cells. Some neurotransmitters
are ‘excitatory’ and make other neurons more likely to fire. Others are
‘inhibitory’ and make them less likely to fire – and more suppressed.
Others have more
complex roles. Some for example will make you more likely to remember
something, while others will make you feel happy or sad. This is what controls
the way you ‘feel’ about certain experiences.
Neurotransmitters
are linked closely with hormones too. Some hormones act like neurotransmitters
while some neurotransmitters can act like hormones. Essentially, hormones are
longer lasting and generally produced in the body, while neurotransmitters have
shorter-lasting effects and are produced in the brain. Even hormones produced
in the body though are largely triggered by the pituitary gland, which is
located in the brain.
See a lion for
instance and your brain will sit up and take notice owing to the associations
you form with that image. Relevant neurons will fire and because those neurons
are coded with danger, they will release a number of neurotransmitters like
dopamine and cortisol to increase activity and say that something important is happening.
This increased activity causes more of the brain to light up and areas around
the hypothalamus will then begin to trigger activity in the pituitary gland,
producing adrenocorticotropic hormone. The adrenal gland will also be triggered
at this point, releasing the hormone epinephrine, which is essentially a form
of adrenaline. This is then what causes changes in the sympathetic nervous
system.
This triggers
physiological changes, including:
- The acceleration of the heart and lungs
- Vasoconstriction (thinning of the blood vessels)
- Dilation of the blood vessels leading to muscles
- Dilation of the pupils
- Sense of dread/anxiety
- Tunnel vision
- Thickening of the blood to encourage clotting after injury
- Pain reduction
- Contraction of the muscles
- Shaking
- Suppression of digestion and immune function
Essentially, the
body now directs all blood, oxygen, nutrients and resources to the muscles and
the brain, in order to aid in combat, escape or other physical activity.
All this is
involuntary and all of this is controlled entirely by automatic responses
throughout your body. And it completely changes the way you now think and the
way your body operates. It changes the way people see you and it drastically
effects the way you perceive everything that happens subsequently.
But it’s not just
during times of high stress that you see such uncontrolled changes throughout
your body. And there are many complex interactions of chemicals and hormones
going on inside your body all the time…
Next week we'll dive further into neurotransmitters and how they interact with our bodies.
Next week we'll dive further into neurotransmitters and how they interact with our bodies.
