Epi-Thinking: Restoring Sagacity to Common Sense
            

              Evoking a new way of thinking.

      Evidence: Roundworms


            In 2011, the New York Times published the first "popular" description of some amazing research into "roundworms."  It turns out that despite the mathematical ability to describe and "map" the function of each of the roundworm brain's 302 neurons once the "mapping" was completed it was discovered to be unmappable due to the presence of a "third system" which acted to turn neurons and synapses on and off dependent upon context.  The Times article explains:

            "is a favorite laboratory organism for several reasons, including the comparative simplicity of its brain, which has just 302 neurons and 8,000 synapses, or neuron-to-neuron connections. These connections are pretty much the same from one individual to another, meaning that in all worms the brain is wired up in essentially the same way. Such a system should be considerably easier to understand than the human brain, a structure with billions of neurons, 100,000 miles of biological wiring and 100 trillion synapses.

            "Each neuron in the worm’s brain is known, and is assigned a three letter name. Specific neurons can be identified under a microscope and zapped with a laser beam, allowing the neuron’s role to be deduced from whatever function the worm may seem to have lost."

            "Why is the wiring diagram produced by Dr. White so hard to interpret? She pulls down from her shelves a dog-eared copy of the journal in which the wiring was first described. The diagram shows the electrical connections that each of the 302 neurons makes to others in the system. These are the same kind of connections as those made by human neurons. But worms have another kind of connection. Besides the synapses that mediate electrical signals, there are also so-called gap junctions that allow direct chemical communication between neurons. The wiring diagram for the gap junctions is quite different from that of the synapses. Not only does the worm’s connectome, as Dr. Bargmann calls it, have two separate wiring diagrams superimposed on each other, but there is a third system that keeps rewiring the wiring diagrams. This is based on neuropeptides, hormone-like chemicals that are released by neurons to affect other neurons. The neuropeptides probably help control the brain’s general status, or mood. A strong hint of how they work comes from the npr-1 gene, which makes a protein that responds to neuropeptides. When the npr-1 gene is active, its neuron becomes unavailable to its local circuit. That may be a reason why the worm’s behavior cannot be computed from the wiring diagram: the pattern of connections is changing all the time under the influence of the worm’s 250 neuropeptides. The connectome shows the electrical connections, and hence the quickest paths for information to move through the worm’s brain. “But if only a subset of neurons are available at any time, the connectome is ambiguous,” she says."

            "What would be required to say that the worm’s nervous system was fully understood? “You would want to understand a behavior all the way through, and then how the behavior can change,” Dr. Bargmann says. “That goal is not unattainable,” she adds."


            Context dependence is thus hard wired into our brains via the neuropeptide system.

            If context dependence is hard wired it cannot be avoided  -- and thus defies the notion of simple perceptions being adequate reflections of "reality."