Theoretical Neuroscience.

Part 1. Background.

“The most beautiful thing we can experience is the mysterious. It is the source of all true art and science. ”

― Albert Einstein

Charles Darwin presented us with an excellent theory about the origin and development of life on Earth. However, Darwin’s theory is still only a theory as it has many controversial points, as well as missing pieces and gaps. The one aspect of Darwin’s theory that makes it hard to properly assess, like many others of its type, is the fact that we have no way to test the theory, so we can neither confirm nor disapprove of it. Regardless of this, we can still use the bases of the Theory of Evolution as a pattern to conceptualize, in our case, how the nervous system developed and what processes occurred to lead to the emergence of consciousness.

Let’s strip this down to the very basics of it all and take a moment to step back and visualize this concept. Let’s presume we have a ton of single celled organisms that are found in, and transported by, streams and waterways. During the day, the sun heats these cells up and then at night,when the sun goes down, they cool off. Taking into consideration Darwin’s theory, we can say that at some point these cells evolved the ability to be able to move and recognize the changes in temperature. We can then go on to assume that over a very long period of time these cells may have began to recognize the need to move to areas where there was more heat available to them to be able to complete their extremely primal internal processes.

A large portion of Darwin’s Theory of Evolution revolves around the less fortunate half of the population that doesn’t evolve in the right way so as to survive. Connecting back to our visualization, we can begin to add the probability that although many cells were able to begin moving towards areas of heat, there were also cells that weren’t quite as successful and ended up in a location where they couldn’t function. As a result, these cells died and decomposed, which would leave a chemical marker in the location of their death. Tapping back into the Theory of Evolution, and building on the same idea of how the cells learned to move and to distinguish changes in heat, we can go on to say that over time the cells could also learn how to differentiate between a normal environment and one that has a concentration of the chemical markings left by the decomposition of dead cells. We propose to refer to this system of differentiation between changes in the environment as “external markers”.

This system of so called “external markers” is relatively simple, but let’s break it down even further into its most elementary components. Going back to our ongoing example with the simple cells, we can begin to see a pattern forming that we can begin to describe as switches of sorts. Whenever there is a repetitive stimulus on an external sensor of the cell, (i.e. presence and then absence of heat), the cell can begin to tell apart when there is a stimulus, and when there isn’t. Since heat, or sunlight in our case, are required by most simple organisms to be able to continue producing energy, the added trait of differentiating between the presence and absence of sunlight would give these cells a higher chance of survival. The cells that learn to adapt to the different stimuluses can then begin to react to them, whether it be recognizing heat and moving towards it from cold to warm, or discerning between the presence of chemical decomposition in an area and knowing to stay away from it because, judging by the marker, something has died there.

This uncomplicated idea of switches in the role of external stimuli is the bases of these cell’s development. We can go on to assume that these organism learned not only to distinguish between things like the chemical decomposition of cells, but also then between the chemical markers of still living cells. Taking into account many species on our planet today, we can see that nature hasn’t missed an opportunity to develop organs and glands in many animals, and even plants, that are capable of excreting various markings into the environment. Throughout the animal kingdom we see this type of communication between species through the external markers that they leave and encounter.

Take for example a bear rubbing up on a tree and leaving its scent to warn other animals that they’re entering its territory, or even skunks, who when scared and triggered release a spray of smell to warn and shock whatever it is that scared them, and also leave a trace for others that this isn’t a safe place.

However, with the growth and development of organisms from single cell to multi cell, evolution has faced a couple of problems. Since the number of cells in a single organism was growing, the number of sensors and switches being flipped by external stimuli was increasing as well. As these organisms developed, it made more and more sense to have all the signal processing chains gathered in one place. In addition, this meant that all the information-heavy sensors such as vision, hearing, and sense of smell weren’t far from each other.

Another problem that needed to be resolved because of the appearance of large number of cells, was that they all needed to work simultaneously and together in order to reach a common objective in a reasonable amount of time. It wouldn’t have made sense to give each single cell it’s own job, so instead, the obvious separation of jobs between groups and clusters of cells occurred. This, of course, created another problem: with groups of cells inside a larger organism working, how were they supposed to coordinate their actions and know when to begin and end their jobs? This is a problem that could be resolved in the same manner that everything began, with the use of “markers”. Except, this time, instead of being external markers and stimuli, they were internal. We can refer to this network as the “Internal Signal System”.

As an example, let’s look at the simplest case of an internal signal sequence, the fight-or-flight response. In a situation where the main control group of cells receives an external stimuli that causes it to react in fear and/or panic from prior knowledge in a previous experience, it sends an internal signal and stimulus to the rest of the cell groups that in turn begin doing their jobs, like one cell group pumping adrenaline out to the rest, or simply preparing to act. In short, the Internal Signal System consists of the core control cell group using stimuli to send signals to other groups so that they all work as one.

At this point of our theoretical study, what we’ve described is simply a system of switches that when stimulated consistently will produce some sort of response. At the same time, most of these switches are physically assembled in one place with the outermost having sensors that receive and translate external markers to the internal network of switches. However, to add on top now, the internal switches are able to react to the markers of the signal system. It’s a rather brutal cycle where in the switches control the signal system, and the signal system acts on the switches.

Let’s look at it from a slightly different perspective. If we have a signal system consisting of 100 switches that are each capable of being either on or off at a given moment, this gives us 2 ^ 100 variations of sequences for combinations for these switches. This gives us a rather large amount of options for combinations to assign to stimuli and then exchanging between cells so that they know what the external stimuli was, and know which of their specific jobs to perform accordingly.

Let’s assume that, at its creation, a group of switches remembers a combination of positions for itself that occurred in response to a certain stimulus. Later in the future, when these same switches appear in the same position again, we can say that it’s the same stimulus as before reoccurring. This provides us with a link between different physically separated groups, and their activation in similar situations.

It’s interesting to note, however, that at some point in evolution, some species lost the ability to recognize external markers. In cetaceans, sirens, most bats, prickly primates, but most notably humans, the vomeronasal organ is completely vestigial. It is known that human hormones can affect animals, but the reverse either doesn’t have any effect on humans, or else the reaction is very small. Whether this disappearance of the vomeronasal organ was due to markers in the internal signal system becoming more primary and external markers becoming unnecessary, or because the network of external markers became inaccessible for some reason and, as result, the internal signal system had to try to make up for it by expanding, is unknown.

In the next part of our article, we will discuss how we can begin to build and organize what we refer to as “consciousness” from sets of triggers and Internal Signal Systems.