Consciousness as a Property of Protoplasm

Believing that consciousness is a fundamental property of all living things, some 19th century biologists saw its essence in the irritability of the smallest one cell organisms. Popular books of this era included, The Animal Mind by M. F. Washburn, and The Psychic Life of Microorganisms by Alfred Bonet. Observation of an amoeba hunting food or responding to various stimuli, or paramecium avoiding obstacles or conjugating led to application of human psychology to such behavior. These concepts were accepted by Charles Darwin and E. B. Titchner, who saw such rudimentary consciousness related to man through the course of evolution.

Circumstantial support for this thesis is found in the inhibitory effects .of general anesthetic gases on protoplasmic streaming in slime molds, and anesthetic inhibition of amoeboid and paramecium motility. This suggests a common link between these primitive organism activities and brain activities related to consciousness in that all are reversibly sensitive to the same anesthetic gas molecules at comparable concentrations. Protoplasmic streaming, amoeboid movement and paramecium motility all depend on dynamic activities of cytoskeletal structures including "computer-like" cytoplasmic microtubules, actin sol-gel transitions, and ciliary appendages (Chapter 5). The cytoskeletal link among anesthetic sensitive processes could be a clue to the brain/mind/computer triangle.

Jaynes objects to protoplasmic consciousness, suggesting that humans may be projecting their own mind functions onto protozoan behavior which he believes to reside entirely in physical chemistry rather than introspective psychology. However, introspective psychology itself is in all probability a function of physical chemistry at some level. If an amoeba, or slime mold, or paramecium are not conscious, at what point in the evolutionary hierarchy does consciousness emerge? Stanford University Professor Karl Pribram (1966), known for his conceptualization of mind functions as "holographic," recalls being confronted with this issue during a lecture at the Montreal Neurological Institute in the late 1950's. Famed neuroscientist Wilder Penfield asked Pribram whether the difference between man and the non-human primates was quantitative or qualitative. Pribram replied that the difference was quantitative but to such an extent that qualitative changes emerged. He cited the relatively new computer technology as an example: vast increases in the capacity of memory and central processors had changed computational power not only quantitatively but qualitatively. Penfield argued for a more fundamental distinction to distinguish man. Pribram countered by saying that, although the only difference in brain structure between man and other animals is quantitative, changes in organization, chemical composition, developmental sequence, and in time and duration of critical periods had led to collective emergence of qualitatively distinctive properties. The quantitative common link of consciousness may be the cytoskeleton within cells ranging from single cell organisms, viruses, (and perhaps more simple "life" forms such as "prions," or independent protein structures) to neurons within the human brain. The qualitative differences appear to lie in nonlinear collective properties related through evolution to structural complexity.

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