1 thought on “The divided brain

  1. DE Teodoru

    Very nice play on 1970s attention/split-brain research. However our dear psychiatrist above– though he used some animals in his drawings– failed to consider the evolution of the brain as a VERTICAL machine. More interestingly, as demonstrated by a brilliant medical student named Dumont in 1985 in a seminal argument in SCIENCE: Evolution does not removes, it ADDS to lower structures and, since the lower reflex arcs on input–>output zip in&out faster than the higher ones (as the higher have not only further to travel but are more multi-synaptic), the higher must INHIBIT the lower while they do their processing so that they can impose modulation on the lower ones– indeed, use them as outputs for their computations. Finally, “INHIBITION” and FASCILITATION” may be all one can expect from electro-magnets, but the diode systems of the brain, like those of computers, can convert “1” and “0” into integrations, disinhibitions and spread vs. narrow foci. So, assigning one function to one cerebral hemisphere and another to the other– even tendencies rather than absolutes, or even the very abstracted end-point function that our psychiatrist friend so beautifully expounds– leaves out that the Central Nervous System is not just left and right, interconnected by the corpus collosum, but an entirety of inumerable AXIAL leftright integrations, beginning from spinal level, through brain stem, on to thalamus, hypothalamus and basal forebrain before one ever gets to cerebral lateralized particularity. Indeed, the cerebral hemispheres, if bereft of sub-cortical input, as the brilliant neurobiologist Bremer demonstrated in the 1930s, put out only basic EEG wave patters whose integral effect we still don’t really understand. In conclusion, the brave particularization vs. specification thesis of our psychiatrist friend is totally speculative and unassailable only because reality is far, far more complex and we’re not yet able to translate the functions he connotes into neuro-circuitry and synaptic activity. One is forced to conclude that, so far, human brain is way beyond us just yet and current fMRI, PET and other colorful computer mock-up models of brain function are really palpatory ventures of the blind into the light. But, then, that’s what makes it so exciting. Thanks for the video!

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