Saturday, September 6, 2014

Electric Intellect

Our post title, Electric Intellect, is intended to be humorous, but it may be more realistic than humorous. “Electric” connotes something thrilling or exciting; intellect refers to mental powers.

Electric charges are possessed by virtually all matter. Electric charges occur in protons and electrons in the atoms and molecules out of which all matter is composed. These charges respond with attraction or repulsion in an electric field. The force of electric charges is ever present in all matter, including our bodies. As a former science teacher I still hear myself declaring to my classes, “All matter is electrical in nature.” Electricity, therefore, plays a role in every activity, every situation, and every event of our lives.

Our blog series on sound and audition established that mechanical sound impulses are converted to digital signals after traveling through the components of the outer, middle, and inner ear. From the cochlea to the auditory cortex and beyond to the lobes of the cerebrum, the impulses become entirely electrical. These digital signals manifest themselves as nerve impulses, or “action potentials.” We repeat: All matter is electrical in nature. Our human intellect, our mental powers, run on electricity. Human intelligence is electric!

The cerebral cortex is more recognizable than most other parts of the brain. It may be described in a number of ways. Visually, we could divide the cerebral cortex into four topographical areas. Each area is responsible for processing the various inputs received from the sensory systems. Other brain areas function in other ways. In our recent posts we followed the sound impulses to the primary auditory cortex. This small region of the brain is associated with the temporal lobe of the cerebral cortex. The temporal lobe is one of its four frontal lobes.

The auditory cortex is the most highly organized sound processing unit in the brain but knowledge of its physiological processes is not entirely clear. It is certain that pitch and other information about sound is preserved. Further processing of sound ensures that we detect and understand speech and subtleties of music. The temporal lobe also has a role in visual recognition of faces, objects, and scenes. Notwithstanding our pride in scientific knowledge, much of what happens in different areas of our brain remains speculative and uncertain. Our usual sense of thorough understanding must be replaced by pure wonder.

A second lobe of the cerebral cortex is the frontal lobe. It is the source of human ability to reason, use expressive language, and achieve higher level cognition. Motor skills are also related to frontal lobe function. The parietal lobe processes tactile sensory information such as pressure, touch, and pain. Verbal memory and certain language skills originate in this area. Finally, the occipital lobe receives messages transmitted from the retina of our eyes and interprets the visual stimuli.

Does our discussion do justice to the electrical wonders of human intellect? Hardly at all! Our treatment touches only minimally upon the field of brain anatomy and function. Textbook and web diagrams covey a bewildering array of graphics on brain anatomy. Written resources fill medical libraries with the expertise gained by specialists. Medical schools pride themselves on their practical knowledge. These sources are able to convey wonder at the complexity of the human brain. At the same time we experience surprise that so little is known about this difficult subject. 

We abide in reverence for the useful knowledge mankind has gained about the anatomical geography of the estimated 86 billion neurons in the human brain. The functional information bank stored in 3.3 pounds of human neural tissue triggers an electric response by those who choose to probe its mysteries. In the human brain abides the essence of the Image of God.