Piero Scaruffi(Copyright © 2013 Piero Scaruffi | Legal restrictions )
These are excerpts and elaborations from my book "The Nature of Consciousness"
An Olfactory Brain
The US neuroscientist Rhawn Joseph argued that the human brain still contains parts that were used by animals that lived hundreds of million of years ago. In other words, we share parts of the brain of many other animals, and, ultimately, one can say that all animals are “linked” by the “collectively shared unconscious” Joseph calls the human body a “living museum” because it contains so many remnants of ancient organs. This is also visible in language: while we have developed sophisticated spoken languages, we still use gestures, that are presumably an archaic form of communication. Old and new languages coexist. We often communicate unconsciously to other beings precisely because we still have, like it or not, the old languages. For example, a facial expression is enough to communicate our state of mind.
Neurons (nerve cells) first appeared 700 million years ago. When neurons got connected, the first brain was born. Joseph believes that the first major grouping of neurons occurred among olfactory cells, that originally may have been external cells. Eventually they migrated inside the body and created an olfactory lobe. Later, a similar fate turned visual cells into the visual lobe. The growth of these two lobes over evolutionary time eventually yielded the brain as we know it (the two hemispheres).
The olfactory lobe also evolved into the limbic lobe, that still controls many of the “instinctive” activities (in both humans and other animals). The cells of the limbic lobe created more and more layers, and eventually created the cortex. Thus the fundamental structure of the modern human brain evolved from the olfactory lobe.
Among the various forms of communication that are crucial to our understanding of the world, Joseph believes that odors play an important role. The nose contains the most exposed (unprotected) neurons of the human body. The mucosa of the nose is directly connected to the hippocampus and the amygdala, which are instrumental in creating memories. It is likely that living beings developed the ability to analyze chemicals (odors) in order to understand changes in the environment and to sense other beings (in fact, our bodies still excrete odor-generating chemicals from the skin). Odors, after all, control sex and aggression and many other basic activities of most species.
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