Tuesday, July 17, 2007

Those gut feelings….

The foundation of a primal self


There is a functional region deep within the core of the mammalian (and possibly most vertebrate) brains that may give rise one of the most basic forms of awareness that has been described as the primal self. This is an area where a variety of sensory inputs and reactionary responses are blended to create a deep, visceral sense of self.


In humans, peeling away the layered complexities of higher cognitive forms of consciousness eventually reveals a primordial self awareness a step above simply reactive neural responses. Based on the precursors of emotions these responses are integrated with sensory inputs to create “intent”, that is a proactive disposition. Jaak Pankepp (Affective Neuroscience) notes “The rudiments of consciousness were probably built upon neural systems that symbolize biological values- the basic motivational and emotional systems of the brain that inform organisms how they are faring in the game of survival.”


These neural networks are concentrated in the primitive midline brainstem regions, near the ventricles, and extend into critical areas of the limbic system. Where these networks converge could be thought of as the source from where core feelings of self arise. This is a core self more profound than a higher self- it is that gut awareness of body.


Among the more dense and ancient midbrain neural convergences, the periaqueductal gray region (PAG) is rich in visceral sensations that stimulate behavioral emotional responses. The PAG also has a multitude of connections to other brain regions that allows other brain/mind (i.e.; other levels of consciousness) to coordinate with emotional responses. Interestingly, when this area is damaged in animals, they lose their sense of conscious “presence” with the world around them.


The PAG is strategically located close to areas that integrate vision, touch, and hearing- a region known as the four twins (the four protuberances along the back of the brainstem identified as the superior and inferior colliculi) as well as other motor regions. The general effect is an integration of internal sensory and motor “mapping” of the body providing appropriate emotionally tagged responses to external stimuli.


It is this functional interaction that provides the dynamic basis for primordial gut awareness. Pankepp concludes “These closely integrated areas appear to neuro-symbolically represent the organism as a coherent living creature and may constitute a core SELF for each organism- a Simple Ego-type Life Force, which provides an archetypal homuncular form, a primal soul if you will- upon which innumerable brain complexities were built.”



Ref:

Carter, Rita. Exploring consciousness. Univ of CA press. California.2002.

Panksepp, Jaak. Affective neuroscience: the foundations of human and animal evolution. Oxford univ press. New York. 1998.

2 comments:

MT said...

Gut? You may be choking on your stem. I'm new to this material but allow me to recommend Bjorn Merker on centrencephalism and the evolutionary history of consciousness...not that he puts a lot of feeling into it.

wandering primate said...

Sure, to a degree, we're all choking on our "stem" and though you may not like the gut analogy-it seems to aptly decribe this unavoidable primal and visceral form of awareness (i.e., kind of like the often inescapable gag reflex).

Whatever human consciousness might actually be, basic reactions to a stimulus likely lie at their core and may correspond to vertebrate (and probably beyond) neural regions that reflect common ground among species. Emotion (an apt descriptor) is integral to this make up- no matter how rational we yearn to be.

Humanity has perhaps taken an extremely "social" hominid evolutionary track giving rise to astoundingly complex communicative skills (i.e., recursion for instance) in response to a constellation of pressures- selective or accidental- resulting in us now (as opposed to us 70,000 years ago- they were likely cognitively different at some level).

The expanding knowledge from many disciplines of scientific endeavor from neuroscience to genomic research seem to be revealing a rather improvised make up for our mushy brains that necessarily built and "improved" (per our unique needs) apon existing systems.

Though not familiar with Merker, he seems to offer some intriguing speculative evolutionary/cultural insights into human biomusicality. Thanks for the input.