Space Brains: Neuroplasticity and Neurological Neoteny

The Star Larvae Hypothesis
Nature's Plan for Humankind
Part 3. Space Brains

Neuroplasticity and Neurological Neoteny

Weightless enrichment juvenilizes brains, extending an underlying trend in human evolution.

Think you're Bright? Rise and Shine at http://starlarvae.blogspot.com/

Brains enriched by weightlessness, or any other environment, do not necessarily bestow higher intelligence to their bearers—at least not intelligence of the sort measured by college-entrance exams or other standardized tests. This is an important caveat, because brain enrichment has acquired a political dimension. Developmental neurology has spawned its own cultural politics. The debate around it is relevant to the star larvae hypothesis because it helps clarify some of the phenomenological implications of brain enrichment.

Educational consultant John Bruer lays out the political dimension of brain enrichment/impoverishment research in "The Myth of the First Three Years". Bruer debunks the popular and politically charged fiction of an irreversible brain "tuning" that occurs during the first three years of life. The brain retains enough plasticity to sprout and weed out synapses throughout life, as Bruer documents, but the issue is politically charged because appeals to the first three years, over the past several decades, have swayed federal and state governments to increase their infant- and toddler-focused social spending. Advocates use the data on brain-plasticity to argue that the first three years of life constitute a limited window of opportunity for brain enrichment.

Bruer acknowledges that brain plasticity is susceptible to enriching and impoverishing influences, but, he cautions, "When it comes to humans, we must be careful not to read 'Upper East Side/Palo Alto' for 'complex/enriched' and 'South Bronx/East Los Angeles' for 'isolated/deprived.'" He prefers "complex" and "isolated" to "enriched" and "impoverished" or "deprived." Regardless, these various labels to a significant degree miss the point. Why should environments interest us more than the behaviors that they elicit? Research results show that developing brains should not be considered passive recipients of environmental inputs, but active agents participating in their own development.

"In the future, power will belong to those peoples with no origins and no authenticity. It will belong to those who, like America from the beginning, can achieve "deterritorialization" and weightlessness and figure out how to exploit the situation to the full extent."

—- Jean Baudrillard
interview in New Perspectives Quarterly
Summer 1989

Inventive minds might cook up endless alternatives to "enriched" and "impoverished" in the pursuit of political correctness (because the concepts might be applied to social classes that tend to live in certain kinds of environments). Alternatively, prospective commentators might be honest empiricists and label the environments according to the behaviors that they elicit. In that case, they would be labeled "high activity" and "low activity" environments. This labeling at least gets around the stigma of social class and breaks the assumed link between enrichment and socioeconomic utility.

I have retained "enriched" and "impoverished" because they have become the standard jargon of developmental neurology. But, if only for the sake of political correctness, this usage should not be taken as a commentary on the fitness of particular types of brains relative to particular types of environments. "Enriched" means simply a condition of more activity and more synapses, and "impoverished" means a condition of less of both. The relative desirability of points on the spectrum between the two extremes of these conditions depends on what an organism needs to do to get along in its environment. At least that conclusion jibes with standard evolutionary theory. Where on the spectrum is the maximum adaptation to comporting a body in weightlessness and where to running a business office downtown?

More, and more complex, neurology does not guarantee improved qualities of mind for any particular purpose, but it would seem to guarantee significantly novel qualities of mind and experience. Synaptic connections that accumulate during a lifetime in weightlessness might swamp the logical, symbol-manipulating intelligence that schooling distills from the naturally rich brains of children. Extreme enrichment might not enhance the cognitive skills that bestow day-to-day utility in a work-for-wages terrestrial milieu. Alternative modes of understanding and experience might dominate brains more amply wired than ours. "Young children often propose brilliant, conceptually correct ideas, yet they cannot take them any further," continues the New York Times (6/24/86) report. "Children seem to daydream. They cannot concentrate for long. All this . . . may be because too many neural connections interfere with sustained logical thought."

Bruer concurs, emphasizing that proponents of environmental engineering for the purpose of maximizing synaptic density in children’s brains, even if they were successful, might do the kids more harm than good. Neural pruning is a normal process that apparently helps organisms conform to the demands of their environments. If underused connections were retained, they might interfere with normal functioning, such as by introducing extraneous signals—noise—into the brain’s information-processing system. Neural pruning, by eliminating excess connections, would seem to improve the fidelity of the brain’s communications network, and hence its efficiency and reliability in performing the particular tasks for which it needs to be optimized.

"Our birth is but a sleep and a forgetting:
The Soul that rises with us, our life's Star,
Hath had elsewhere its setting,
And cometh from afar.
Not in entire forgetfulness,
And not in utter nakedness,
But trailing clouds of glory do we come
From God, who is our home:
Heaven lies about us in our infancy!"

— Wordsworth
from Intimations of Immortality

The enriched brains of native extraterrestrials, packed with what on Earth would be excess connections, may not only be unsuited for the intellectual tasks typically tested with pencil and paper, or carefully aimed mouse clicks. They are more likely to exhibit mental propensities conspicuously freewheeling, or juvenile.

By preserving synaptic connections that whither from neglect when brains develop on Earth and by assimilating a maturing population of new cells, space brains will exhibit neoteny. They will remain juvenile—retaining high synaptic density in a large neuronal population—into adulthood. Neoteny is defined by evolutionary biologists as a retardation of development. It produces adults with juvenile features. Neoteny is a well-trod evolutionary path, a mode of adaptation typically resorted to by species that live in rapidly fluctuating environments.

Moreover, human beings seem to be primary artifacts of neotenous evolution. Harvard paleontologist Stephen Jay Gould was an outspoken champion of this interpretation of the fossil record. Gould argued in several books that adult humans are infantile on a number of measures, from dental patterns to head-torso-limb (allometric) proportions. From the fossil evidence he concluded that, "[A] general, temporal retardation of development has clearly characterized human evolution. This retardation established a matrix within which all trends in the evolution of human morphology must be assessed" (in Ontogeny and Phylogeny). As a result of this trend, human adults resemble the infants of other primates more than they resemble the adults.

Gould resisted prophesying the future of human evolution, but it would seem that the neotenous trend will continue and accelerate in space—as bones soften, muscles thin out, and brains bulk up. For load-bearing tissue—bone and muscle—gravity is an enriching environment and weightlessness an impoverishing one. For mind-bearing tissue the opposite would seem to be true.