#5. Why We Dream [neuroscience]

NE
Red, theory; black, fact.

The Melancholy Fields

Something I still remember from Psych 101 is the prof's statement that "operant conditioning" is the basis of all voluntary behavior. The process was discovered in lab animals such as pigeons by B.F. Skinner in the 1950s and can briefly be stated as "If the ends are achieved, the means will be repeated." (Gandhi said something similar about revolutionary governments.)

I Dream of the Gruffalo. Pareidolia as dream imagery.

Let's say The Organism is in a supermarket checkout line and can't get the opposite sides of a plastic grocery bag unstuck from each other no matter how it rubs, blows, stretches, picks at, or pinches the bag. At great length, a rubbing behavior by chance happens near the sweet spot next to the handle, and the bag opens at once. Thereafter, when in the same situation, The Organism goes straight to the sweet spot and rubs, for a great savings in time and aggravation. This is operant conditioning, which is just trial-and-error, like evolution itself, only faster. Notice how it must begin: with trying moves randomly--behavioral mutations. However, the process is not really random like a DNA mutation. The Organism never tries kicking out his foot, for example, when it is the hand that is holding the bag. Clearly, common sense plays a role in getting the bag open, but any STEM-educated person will want to know just what this "common sense" is and how you would program it. Ideally, you want the  creativity and genius of pure randomness, AND the assurance of not doing anything crazy or even lethal just because some random-move generator suggested it. You vet those suggestions.

That, in a nutshell, is dreaming: vetting random moves against our accumulated better judgment to see if they are safe--stocking the brain with pre-vetted random moves for use the next day when stuck. This is why the emotions associated with dreaming are more often unpleasant than pleasant: there are more ways to go wrong than to go right (This is why my illustrations for this post are melancholy and monster-haunted.) The vetting is best done in advance (e.g., while we sleep) because there's no time in the heat of the action the next day, and trial-and-error with certified-safe "random" moves is already time-consuming without having to do the vetting on the spot as well.

Dreams are loosely associated with brain electrical events called "PGO waves," which begin with a burst of action potentials ("nerve impulses") in a few small brainstem neuron clusters, then spread to the visual thalamus, then to the primary visual cortex. I theorize that each PGO wave creates a new random move that is installed by default in memory in cerebral cortex, and is then tested in the inner theater of dreaming to see what the consequences would be. In the event of a disaster foreseen, the move is scrubbed from memory, or better yet, added as a "don't do" to the store of accumulated wisdom. Repeat all night.

If memory is organized like an AI knowledge base, then each random move would actually be a connection from a randomly-selected but known stimulus to a randomly-selected but known response, amounting to adding a novel if-then rule to the knowledge base. Some of the responses in question could be strictly internal to the brain, raising or lowering the firing thresholds of still other rules.

(Deprecated, Part 3)

In "Evolution in Four Dimensions" [1st ed.] Jablonka and Lamb make the point that epigenetic, cultural, and symbolic processes can come up with something much better than purely random mutations: variation that has been subjected to a variety of screening processes.

Nightmares involving feelings of dread superimposed on experiencing routine activities may serve to disrupt routine assumptions that are not serving you well (that is, you may be barking up the wrong tree).