In today’s excerpt – there are over ten trillion cells in the human body – some estimates are far higher – and one hundred billion in the brain alone, yet all these are disproportionately affected and governed by the eighty thousand spindle cells that are involved in handling emotion and moral judgment. (Spindle cells are found in abundance in the anterior cingulate cortex, which has strong connections to the amygdala – the site where our first emotional judgments begin):
“[We are attempting] to [better] understand how human brains differ from those of other mammals. The answer is that the differences are slight but critical, and they help us discern how the brain processes emotion and related feelings. … [A] key distinguishing feature is that emotionally charged situations appear to be handled by special cells called spindle cells, which are found only in humans and some great apes. These neural cells are large, with long neural filaments called apical dendrites that connect extensive signals from many other brain regions. This type of ‘deep’ interconnectedness, in which certain neurons provide connections across numerous regions, is a feature that occurs increasingly as we go up the evolutionary ladder. It is not surprising that the spindle cells, involved as they are in handling emotion and moral judgment, would have this form of deep interconnectedness, given the complexity of our emotional reactions.
“What is startling, however, is how few spindle cells there are: only about 80,000 in the human brain (about 45,000 in the right hemisphere and 35,000 in the left hemisphere). This disparity appears to account for the perception that emotional intelligence is the province of the right brain, although the disproportion is modest. Gorillas have about 16,000 of these cells, bonobos about 2,100, and chimpanzees about 1,800. Other mammals lack them completely. …
“These findings [regarding spindle cells and related activities] are consistent with a growing consensus that our emotions are closely linked to areas of the brain that contain maps of the body, a view promoted by Dr. Antonio Damasio at the University of Iowa. They are also consistent with the view that a great deal of our thinking is directed toward our bodies: protecting and enhancing them, as well as attending to their myriad needs and desires.
“A tiny area at the front of the right insula [of the brain] is called the fronto-insular cortex. This is the region containing the spindle cells, and fMRI scans have revealed that it is particularly active when a person is dealing with high-level emotions such as love, anger, sadness, and sexual desire. Situations that strongly activate the spindle cells include when a subject looks at her romantic partner or hears her child crying. …
“Interestingly, spindle cells do not exist in newborn humans but begin to appear only at around the age of four months and increase significantly from ages one to three. Children’s ability to deal with moral issues and perceive such higher-level emotions as love develop during this same time period.
“The spindle cells gain their power from the deep interconnectedness of their long apical dendrites with many other brain regions. The high-level emotions that the spindle cells process are affected, thereby, by all of our perceptual and cognitive regions. … It is remarkable how few neurons appear to be exclusively involved with these emotions. We have fifty billion neurons in the cerebellum that deal with skill formation, billions in the cortex that perform the transformations for perception and rational planning, but only about eighty thousand spindle cells dealing with high-level emotions. It is important to point out that the spindle cells are not doing rational problem solving, which is why we don’t have rational control over our responses to music or over falling in love.”
Author: Ray Kurzweil
Title: The Singularity is Near
Date: Copyright 2005 by Ray Kurzweil
The Singularity Is Near: When Humans Transcend Biology
by Ray Kurzweil by The Viking Press
If you wish to read further:
Should you use the above link to purchase a book, delanceyplace proceeds from your purchase will benefit a children’s literacy project. All Delanceyplace profits are donated to charity.