BRAIN LATERALITY REVISITED

I was presently surprised to stumble across this recent TED production by Iain McGilchrist on the divided brain. It demolishes earlier “scientific” claims about our right and left hemispheres and the “superiority” of the right hemisphere – touted only a few years ago by other TED presenters to great acclaim.  Although the popularized version of the split brain was reported wrong over a decade ago, it persisted even among many scientists – and probably even to this day. Although I tend to support the findings in this latest TED presentation [I also like the means of presentation – a topic for dialog, later] our lesson to be learned is that we today have only incomplete and probably some inaccurate ideas about behavior/mind/brain relationships. Although we cannot wait until we have absolute certainty about ourselves (if ever), we must move forward in designing better models of Humanity being open to what we know and what we don’t know about ourselves and how we function and change.

 
I was fortunate to retrieve two comments I made earlier on social media sites related to this issue.  In both I reference the corpus callosum and its continuing puzzling function – given that it is very late to mature in humans. Two additional data are mentioned in the TED presentation. 1) that the size of the corpus callosum relative to whole brain size has shrunk significantly during human evolution. 2) that the function of the corpus callosum may primarily be inhibitory.

  • The claim that the left brain is dominant for many people is not a scientific fact. Increased blood flow and more neural activity occurs in the left hemisphere during certain types of experiences. But this higher energetics doesn’t imply dominance. The right brain and the emotional centers may serve as elites dictating the multitudes of soldier neurons in the left to march to their drives and rationalize. Brain laterality is more a subtle dance and laterality differences are found in many mammals so we can’t blame the left for language dominance.  It is also an unsolved puzzle that the corpus callosum that connects the two hemispheres is one of the last parts of the brain to mature in humans.  Young children thus may function more like those split-brain subjects. I speculate that this late inter-hemispheric connection is to protect the separate specialized functioning of each hemisphere from too early interference – a breakdown of this barrier I speculate may be one source of autism. Finally, one might consider inter-hemispheric perception, where each hemisphere treats the other as the brain treats the eye retina. Patterns in each hemisphere are perceived by the other hemisphere. The left brain may analyze into structures and categories what it receives from the right brain.  The right brain may create synthesis patterns from the categories it detects in the left brain. Possibly this analysis-synthesis process may cycle to higher and higher levels, the higher levels only to be achieved by special technologies and practices.  –comment in Glisten’s blog in Facebook, 02/20/12.
  •  There are biological maturation developments even into the 20s – and we don’t know what these new neural circuits enable. It has always fascinated me that the corpus callosum (which links the higher levels of the separate hemispheres) is one of the LAST parts of the brain to mature. Are children functioning as split-brain beings? Hardly, but? I inferred from Haidt’s book (on Intuitive/Emotional/Fast/Elephant vs Rational/Conceptional/Slow/Rider) that these two radically different ways of functioning takes considerable time to adjust to each other. Letting their linkage develop slowly may have been a significant factor in humankind achievement emerging our unique sets of competencies in adulthood. Problems some have may be due to a premature merging of left and right hemispheres. CAUTION: brain asymmetry is far more complex than the simplistic in the lay (and even some scientific) discourse about the distinctive differences between right and left hemispheres. This dodges the query as why children have their own versions of higher level competencies. We also need to consider the significance of the very existence of savants.  Comment to Charity Kalinovka, 12/31/2012.

The TED presentation ends with a discussion of the “battle for dominance” of the rational vs intuitive. This battle is also covered from two slightly different perspectives in Thinking, Fast and Slow by Daniel Kahneman and The Righteous Mind: Why Good People Are Divided by Politics and Religion,  Jonathan Haidt. I am sure the literature is chock full of reports of recent studies about the interplay between these different functions.  I prefer to view these dynamics as a complex dance, which can occasionally be tied into destructive knots as individual humans are locked-into their reinforcing environments.

ADDENDUM: The nature of the “unconscious” remains in controversial limbo – although there seems to be little interaction between the various schools.  There remain some who believe the unconscious is only a reservoir of repressed ideas. Others see it as the chaotic font of creativity. Some models neglect it entirely, using only the conscious and subconscious. Many claim “consciousness” as the only reality and tout “conscious awakening” as the only route to positive human change, tending obliviousness as to what people will really do when “awakened”. Except – that many of these believe they have awakened and their task is to awaken others – and once all are awakened miracles will happen.  Others believe that deeper explorations of consciousness will lead them to transcend personal consciousness.

  •  I have my own models and uses of this terminology. I use the c-word only in reference to its use by others.  I prefer “experientials”, holding to a distant future the nature of the “experiencer”.  I also avoid sub-c and un-c terminology – in satire to calling tree branches and trunks, sub-leaves and tree roots, un-leaves. Why do we reference the whole to the latest part – like describing an iceberg in terms of the part above the surface.  Elsewhere I attempt to propose a primary brain/mind competency as “world-weaving” and that woven-worlds are living beings (of a new type) hosted by the mind/brains of the person. Experientals and behaviors are outputs from woven-worlds.  This proposes a figure/ground reversal: from 1) the traditional perceptual/motor flow of information from senses to muscles, modulated by memory, to 2) an autopoietic view where behavioral output from the inner-woven world is modulated by input from the senses.  Actually, since models are mental constructions, both models can apply at times for different species and for humans in different circumstances.
  • WORK IN PROGRESS:  Might we view the whole assembly of human scientific views of human systems beyond the immediate perceptual in analogy to classical physics before the insights of Relativity and Quantum Epistemology?  Might our way out of our Crisis-of-Crises be assisted by a new view of societal reality that transcends our classical view as QM transcends classical physics and makes possible our modern technological achievements.  We need new and innovative human system technologies that may become evident once we view ourselves from different epistemological assumptions.

 

Author: nuet

01/24/1935. BS-physics RPI 1956; MS-physics UofChicago 1958; PhD-physics Yale 1965; PhD-Edu Psy Uof MInnesota 1970. Auroral Research Byrd Station, Antarctica 11/1960-02/1962. MINNEMAST curriculum dev 1964-68. Woodstock. faculty Pima Community College, Tucson 1974-1997. Transdisciplinary scientist, philosopher, educator, futurist, activist. PC user since 1982. "Wife". daughter, 2 grandsons. 5 dogs & 7 cats. Lacks mental imagery in all sensory domains.

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