The Cortex

Lesson 10

This lesson concerns the cortex. The cortex comprises the uppermost layer of the brain and is considered the highest center of the brain's function. Your "action potential," your behavior or output to the world, is derived from activity in this portion of the brain. This is the portion of the brain that analyzes and decides. It provides for reflection on the multiple inputs provided to the brain. In short, it is "the thinking you."

The cortex has areas that receive very specific information such as a particular musical note heard from your right ear. This goes to a small group of cells in your left temporal lobe. A black, vertical line seen in your left field of view eye goes to a specific part of your right occipital lobe. A cold touch on your right thumb goes to a specific spot in the sensory cortex of your left parietal lobe. These are primary cortical areas.

Huge areas of our brain are devoted to connecting these primary regions and linking information from different primary sensory and motor cortical regions. These cortical regions are described as associative cortex. This large amount of associative cortex distinguishes us as humans. A large volume of the cortex is comprised of white matter tracts or “U fibers” that connect various cortical regions with one another. As an example, the corpus callosum is one large bundle of axons that connects the right and left sides of our brain. 

A simple task such as reading aloud requires connection between the visual brain, the auditory brain, the motor cortex that controls the lips, eyes, hands, vocal cords and the language centers. To provide some emotional impact to the reading, your memories, limbic system and autonomic system need to be in on the performance too.

Similar inputs from the world become associated with different personal experiences. If you were stung by a bee and developed severe swelling and itching, the next time you heard the buzz of a bee your associations would be different from those of a person who associates bees with their grandpa’s bee farm and warm honey.

The associative cortex and its connections help to make you the individual you are. As described above, the black line, auditory tone and thumb movement could be a moment at the piano or a moment at the video game controller. The primary cortical events are similar but the connections of the associative cortex make each event different.

These connections are very fragile. So are the associations that make you who you are. You as an individual are very fragile, HANDLE WITH CARE.

The lesson I would like to impart is just how tenuous the linkage is between your brain’s function and your individuality. Traumatic injury can readily disrupt the circuitry of the brain and render it permanently nonfunctional. The shearing forces of an impact can cause you to be irreparably harmed. A traumatic injury can result in you slipping away from what is left of your brain. 

Don’t take risks that can result in your individuality being stripped from you.