Peter: Human beings are unique among the
animal species in that we have a large ‘modern’ brain – the neo-cortex – capable of thinking, planning and reflecting which overlays
the primitive reptilian brain – the amygdala – the source of the instinctual passions of fear, aggression, nurture and desire. This diagram
forms the scientific neuro-biological basis of what it is we are doing on the wide and wondrous path to Actual Freedom.
Recent studies by LeDoux and others empirically confirm that the ‘quick and dirty’ instinctual, passionate responses
of the primitive brain are primary and automatically over-ride the thoughtful, considered responses of the neo-cortex.
We are, in fact, genetically programmed to be
driven, consumed or overwhelmed by the animal instinctual passions that give rise to malice and sorrow. Thus, in spite of all our best and
well-meaning efforts to keep our malice and sorrow under control, we are but ‘animal’, at our very core.
LeDoux’s studies concern the relationship
between the thalamus, the amygdala and the neo-cortex. The most significant fact of LeDoux’s experimentation is that the sensory input to the
brain is split at the thalamus into two streams – one to the amygdala and one to the neo-cortex. The input stream to the amygdala is
significantly quicker – 12 milliseconds as opposed to 25 milliseconds to the neo-cortex. Also, less information goes to the amygdala – it
operates as a quick primal scan to check for danger, or opportunity, which is why it is described as the ‘quick and dirty’ processing
pathway.
This dual pathway not only results in automatic
instinctual bodily responses but the amygdala also has a direct connection to the neo-cortex – ie we sensately experience the resultant
chemical flow a split-second after the bodily reaction, causing us to ‘feel’ the instinctual response.
These investigations also substantiate the fact
that no matter what degree of control is exercised by the neo-cortex in terms of morals, ethics, good intentions, etc., when ‘push comes to
shove’ we revert to type – and reverting to type means animal-instinctual.
This flow of chemicals, experienced in the neo-cortex, the heart and
the ‘gut’, are the very palpable source of our instinctual emotions of fear, aggression, nurture and desire. |