Our Super-duper Cerebral Cortex
Welcome to stren #64: What Makes Us Human? Wisdom is based on knowledge. Sages throughout the ages have advised us: “Know Thyself.” Let’s modernize the syntax by writing “Know our self,” specifically the self of self-mastery. What is it that makes me “me”? And how am I different than “not me”? We share many similarities with other species but recognizing the special features of our human brain provides us the biggest payoff. Here are some things worth knowing.
- Our brain is among the most complex of all structures. When I was in medical school, I was told it consisted of 100 million cells. Today’s technology reveals that our human brain contains 100 billion cells with 100 trillion connections. If each of the nearly 7 billion people on earth were represented as one cell, our brain would hold everyone and have room for 14 more such collections. Can you imagine creating a machine with so many parts?
- Scientists tell us life on earth began 3½ billion years ago when simple chemical structures became sufficiently complex to reproduce themselves. Single celled organisms progressed to those with two or more cells, and the number of component cells has gradually increased to the present time, where our most complex species have specialized organs working together to promote the survival of that species.
- The first life was brainless and mindless. Simple cells have receptors that draw them to or away from heat or light. As the number of cells increased, chemicals and nerves were introduced to coordinate activities. Simple wiring evolved into a nerve net and then a mass of nerve cells. Some nerves became specialized to receive messages and others to transmit data. When a receiving and transmitting wire are connected by a nerve cell, a “reflex” response is created, such as a knee jerk. Our spinal cord consists of vertical rows of such reflex systems.
- A mass of nerve cells that coordinates the activities of other cells is called “a brain.” The earliest central mass of cells expanded in time to a point where continued growth was attained by an outcropping from the central mass. Can you visualize how one outcropping may lead to another ... and another as more control and wiring was required?
- The simplest brains served to coordinate activities but were “mindless.” We can understand that conscious awareness required greater sophistication. What about becoming conscious of our consciousness, i.e. self-consciousness? Historically, the progression in complexity from one to multiple segments is slow and gradual; greater awareness is to be expected with each increase in brain complexity.
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