Nerves and the gaps between them are a violent synaptic space where strong cultural forces froth for control over human destiny.
Multi-billion dollar industries have gambled that the nerve really is like a binary gate, and that the brain really is like a computer; and whole academic disciplines are founded on that metaphysical assumption.
The cultural forces arrayed on the side of this simple metaphor, this metaphysical article of faith in an equation that cannot be true - these forces are so strong that perhaps the nerve itself has been effaced and no longer makes a difference/différance; perhaps the nerve itself has disappeared so that we can hardly know what it is through conventional means of inspection, any more than we can know the status of a subatomic particle in mid-flight or how an individual gene knows whether to express itself as skin or lip or eye.
Only recently has the paradigm of the neuron been edited away from its status as a kind of underwater telephone cable. (A recent ad for the National Multiple Sclerosis Society plays the sound of a telephone getting a busy signal.) What we say today about the nerve is:
- Neurons act directly, i.e., as neurotransmitters, but they also act at a distance, i.e., as neuromodulators that emit or seep various chemicals which change the ecology or environment in which they and their partners operate. They can affect the responsiveness of hundreds of neurons, hundreds of neurons away, very rapidly.
- The connectivity of neurons changes within five minutes of learning a task. They alter their own structure at the molecular level.
- Neurons create their own pathways with use but they also wither with neglect. (Use it or lose it: the principle of neuroplasticity.)
- Neurons can have use for more than one neurotransmitter, and they can change the neurotransmitters they use by a process not completely understood. In a sense, then, they signal the environment about what they need or can respond to. This process is discontinuous: the nerve stops using one when it starts using another neurotransmitter.
- We don't know how neurons hold signals. Do signals arc pre-synaptically, post-synaptically, or within the neuron itself? What then is the significance of the switch from one neurotransmitter to another?
- Neurons abhor a vacuum. They fill space indiscriminately, randomly. If a part of the brain is excised, neurons will move and grow to fill that space, but not because of any physical or chemical pressure that we can determine. (In other words, it's not because their mitochondrial factories increase energy and protein production, or because they are pushed by chloride ions seeking to fill quantum numbers with sodium ions.)
- The distinction between soma-axon-dendrite is fluid. An axon, under certain pressures, can act as a dendrite, and vice versa.
- Axon branches can act as "demultiplexers" or filters of a signal. They filter signals in proportion to their physical thickness, so that their impedance matches their thickness matches the frequency of the signals they filter.
90% of neuronal action is inhibitory, not excitatory. If you want a light to shine in a certain pattern, it is easier to build a bright light that shines indiscriminately and place a cutout template (silhouette) in front of it than it is to build a light that will shine in that pattern. Also, the brain would overload from sensory input if the nerve was primarily an excitatory and not inhibitory instrument.
In short, the nerve ain't an underwater telephone cable. Maybe it's a pun.
When two words share a prefix, or any other etymological root, they trace an embedded history, a secret history, in which Talmudists, poets, punners, kabbalists, postmodernists like John Barth and poststructuralists like Derrida have a very strong belief.
This belief is that words preserve a faith-full grammatology, a summoning to faith of some true trace of meaning that is lost in casual speech - or even witty, intimate punning dialogue ("two-tonguing"). The reader then becomes a superstitious being, in the sense that the etymology of superstition is "to stand after and bear witness."This true, superstitious trace, or trace of the truth, can only be carefully identified when the words are written down, and can only be faithfully resurrected when the etymology is conjured up in writing. Like reading - that is, really reading, with a sure slow hand (or eye) - a good Rich poem, which in turn must have been slow to write.
Such etymologies, if performed rigorously as well as playfully, form a science that gives us a map not of nature directly but of how knowledge is formed, a map of lines preserved in language as words grow, take on new applications through metaphor, branch out to embrace new meanings and discoveries, and form entangled root structures - like a system of shining paths, neurons - that are beyond rational reduction or inspection.
Adopting the multiple scleroses, the dysfunction of paronomasia, a form of aphasia, as the root of a metaphysical episteme leads us then to reflect not only on the impoverishment of traditional metaphors for the nerve - switch, wire, cable, servomechanism, transistor, hologram - but to be hungry to apply this new perspective, to take it out for a spin around the neurological block. So in the time remaining, let's see if we can get a little joyride out of this poetic punning, this PP approach to the nerve.
In a 1994 article, authors Salvatore Aglioti, Andrea Bonazzi and Feliciana Cortese of the University of Verona report their findings from patients who ... well ...
Three lower-limb amputees who reported phantom sensations referred somatic stimuli delivered to skin regions proximal to the stump to select points on the phantom limb. Stimuli on the rectum and anus (e.g. during defecation) and on the genital areas (e.g. during sexual intercourse) induced analogous, although less precise, mislocation to the phantom limb. Although the representation of the stump in the somatosensory pathway is lateral to that of the amputated lower limb, both anus and genitals are mapped medially to the areas formerly subserving the amputated lower limb. Therefore the mislocalization phenomenon can be considered as a perceptual landmark of new functional connections between the deprived areas and the adjacent ones, thus suggesting a dynamic neural remodelling in the mature nervous system, which was previously considered as a static entity.
In other words, the nervous system creates a virtual reality out of its pre-organized map of a body that is no longer all there. It projects a technology for fooling the brain into thinking it's riding a body somewhere where it isn't; contained within the secret of neural plasticity is the technology of the brain fooling itself. The trouble is, this isn't a technology at all. It is what the brain does best in its default, and dare I say its most natural state: the phantom limb experience is not only not the most haunting and bizarre of summary neural activities, it is the most commonplace, ordinary and pedestrian.
This madness is a sub-version,
the postulation of an alternative episteme that percolates along as a sub-cross-current
of Western culture.
1. Salvatore Aglioti, S. Andrea Bonazzi & Feliciana Cortese, "Phantom Lower Limb as a Perceptual Marker of Neural Plasticity in the Mature Human Brain" in Proceedings of the Royal Society of London. Series B - Biological Sciences (255, 22 Mar 1994).
2. ORIGINS AND HISTORY OF CONSCIOUSNESS
Adrienne Rich, 1972-1974
I
Night-life. Letters, journals, bourbon
sloshed in the glass. Poems crucified on the wall,
dissected, their bird-wings severed
like trophies. No one lives in this room
without living through some kind of crisis.
No one lives in this room
without confronting the whiteness of the wall
behind the poems, planks of books,
photographs of dead heroines.
Without contemplating last and late
the true natures of poetry. The drive
to connect. The dream of a common language.
Thinking of lovers, their blind faith, their
experienced crucifixions,
my envy is not simple. I have dreamed of going to bed
as walking into water ringed by a snowy wood
white as cold sheets thinking, I'll freeze in there.
My bare feet are numbed already by the snow
but the water
is mild, I sink and float
like a warm amphibious animal
that has broken the net, has run
through fields of snow leaving no print;
this water rushes off the scent -
You are clear now
of the hunter, the trapper
the wardens of the mind -
yet the warm animal dreams on
of another animal
swimming under the snow-flecked surface of the pool,
and wakes, and sleeps again.
No one sleeps in this room without the dream of a common language.
II
It was simple to meet you, simple to take your eyes
into mine, saying: these are eyes I have known
from the first....It was simple to touch you
against the hacked background, the grain of what we
had been, the choices, years....It was even simple
to take each other's lives in our hands, as bodies.
What is not simple: to wake from drowning
from where the ocean beat inside us like an afterbirth
into this common, acute particularity
these two selves who walked half a lifetime untouching -
to wake to something deceptively simple: a glass
sweated with dew, a ring of the telephone, a scream
of someone beaten up far down the street
causing each of us to listen to her own inward scream
knowing the mind of the mugger and the mugged
as any woman must who stands to survive in this city,
this century, this life....
each of us having loved the flesh in its clenched or loosened beauty
better than trees or music (yet loving those too
as if they were flesh - and they are - but the flesh
of beings unfathomed as yet in our roughly literal life).
III
It's simple now to wake from sleep with a stranger,
dress, go out, drink coffee,
enter a life again. It isn't simple
to wake from sleep into the neighborhood
of one neither strange nor familiar
whom we have chosen to trust. Trusting, untrusting,
we lowered ourselves into this, let ourselves
downward hand over hand as on a rope that quivered
over the unsearched....We did this. Conceived
of each other, conceived each other in a darkness
which I remember as drenched in light.
I want to call this, life.
But I can't call it life until we start to move
beyond this secret circle of fire
where our bodies are giant shadows flung on a wall
where the night becomes our inner darkness, and sleeps
like a dumb beast, head on her paws, in the corner.