Tag Archives: Brain evolution

197. Brain and Computers Compared (Revised)

28 Dec

Brain-Vs-Computer-Pic2This essay is an addendum to my previous blog-193 “Brain uploading ideas are nonsense.”  It also provides my understanding of what is known about human brain functioning.

Those interested in downloading a human brain into a computer, and have it function, such as answering questions, should consider this. Although the human brain can be called a computer, it is profoundly different from a man-made computer. THE FIGURE above illustrates the fixed regularity of a computer (upper box) with every component specified and with definite location. The Brain below shows a changing and branching structure, where the actual array of components is the “program.”  Every human experience makes at least a slight structural change. Converting from an entire brain configuration with quadrillions of control points,  to an equivalent computer representation, I assert is impossible. (More explanation below.)

BRAIN AND MAN-MADE COMPUTERS ARE VERY DIFFERENT

Man-made computers have a FIXED structure of electronic components. Modern microchips have thousands of transistors and other components in a well-defined, set pattern. Computer programs, cause the chips to function. When a computer is activated by a program, it makes use of many of the components, such as microscopic transistors, so that something meaningful can go to output devices like printers or screens. In a word, the electronics are fixed and the program varies. Note: a “computer program” is a set of instructions that can be written down or typed into a file that can be “read” by a computer. It tells the computer how to utilize its well-defined components in performing certain tasks. There can be many programs to provide for a wide variety of computer functions.

The human brain is nothing like this. A live brain in a body, is constantly changing. Instead of using an external set of programming statements to control the action, the control components themselves (such as transistors) quickly vary to produce a certain output. These variations include additional nerve cells, additional connections, and each connection (a synapse or gap junction) can undergo substantial change. A synapse, based upon its chemistry and inter-connections, can be more excitable, blocked, or anything in between. The nerve cells, axons, and dendrites form branching structures that provide many paths for its operation.

THE BRAIN FUNCTIONS BY CHANGING ITS STRUCTURE

If you look at a magnified computer microchip you will see regular rows of components. The components will vary in different places, but within each part, there is exact duplication.

But in a brain, you will see great variation in size, shape, and connectivity. The “program” is built into the “brain electronics” and varies as the individual is exposed to many different environmental factors, such as learning, imitation, memorization, food supply, social features, etc.

THE BRAIN IS LIKE A CITY, WITH MANY ROADS AND PATHS

Here is a helpful analogy. Think of the brain as a city with millions of roads and pathways. The sensory systems, like vision, hearing, and touch are roads leading into the city — and there are roads going outbound causing the movement of muscles, activating vocal cords, affecting glands, etc. Between the inputs and outputs are millions of pathways with wide streets and narrow paths, free-flowing and constricted in various ways, all to provide something meaningful. At millions of junctions (synapses, etc.) there are traffic cops that speed things up or block the passage. If someone pinches your arm, action potentials flow down wide roads (axons) leading to the brain and spinal cord. Within these structures there is a maze (inter-neurons) that quickly processes the input information and activates outbound pathways, or simply stores info. (This maze is where complex thinking takes place.) The outbound paths (motor nerves) lead to many muscles that can move your arm, body, and make you say “ouch.” If you are pinched over and over again, the relevant pathways tend to widen, causing increased flow and a more efficient reflex. In our city (brain) there are also archive centers that store memories, and other mechanisms that enhance the whole process.

The ability of a brain to function in this way developed over several billions of years. It is a marvelous structure and its exact functioning at the nerve cell level is still unknown. But we can make good educated guesses as to how much of it may work. We don’t know exactly how words and ideas are stored. And we don’t know exactly how millions of memories are accessed during a wide range of operations, and how a brain creates an essay or scientific theory. Yet, the fact that there are many trillions of “control points” (like transistors) suggests that amazing things can result.

A DEAD ISOLATED BRAIN CANNOT PERFORM IN ANY WAY

I might add that a disembodied dead brain can never function like it did live in a body even if fully preserved. Cutting out a brain removes inputs, outputs, the spinal cord, and feedback loops that are critical to functioning. And would involve damage to the brain itself. A removed brain can never be the same as a live intact brain so any hope of living-on in a computer representation is impossible.  Any sectioning of a brain would destroy many interconnections.

Consider this fantasy. You transfer a brain into a computer, and it can talk. Most likely it would scream, “I can’t see, I can’t feel my legs or arms, I can’t hear, I can’t touch  anything,  where am I, HELP!” How could you talk to this isolated brain that has no ears. So you would really have to save a whole head and even the spinal cord. As you contemplate all of these difficulties, it is clear that trying to save a human brain, which can function, is nonsense. Also, for all the reasons outlined above, it is not possible to “read out” specific thoughts or ideas, by any brain recording method.  (Note: recording sub-threshold “thoughts” from vocal cords is not a brain recording.) 

I might add that although uploading a useful brain, or reading specific thoughts, is not possible, what is remotely possible is a good understanding as to how a brain functions at all levels. This could take decades or even centuries, but it is worth discussing and exploring.

 

119. How Humans Evolved

28 Aug

The latest issue of Scientific American (September 2018) is concerned with the issue of how we humans are different from other animals. The issue title is: “A Singular Species: The Science of Being Human.” A lot of this valuable issue is concerned with evolution. As I looked through the issue, I tried to find a discussion of certain details about how evolution actually produced our superior brains.

Here is my analysis.  First, what is necessary for biological evolution is the following:

1. Death, which leads to many generations, that can make small incremental changes.

2. Mutation: A change in DNA that is relatively permanent.

3. Survival of the fittest. The key to understanding “fittest” is that there is a combination of traits in an individual that will allow him (and her) to reach the age for sex and child rearing. The mutation and progeny must live long enough to promote the reproductive cycles. These are the main themes, but many details are involved in the whole process of evolution.

An overall observation, is that evolution is a tree process rather than a number of parallel lines. Some detail about primates is instructive. Primates include lemurs, lorises, monkeys, apes, and man. All primates are mammals and have advanced binocular vision, grasping ability, and specific enlargements of brain.

60 or 80 million years ago there was a key species that had the capability of leading to various primate species. There are many primate variations that have been successful. Some species will continue because they are “fit” and those less successful may terminate, that is, become extinct. The branching tree of evolution will lose some branches and gain new ones. The species we see today, have all been good at all the many requirements for survival. The lemurs, monkeys, apes, etc are all successful variations.

The interesting fact is that perhaps a hundred million years ago, a mutant was born that had a DNA structure that could eventually lead to the evolution of humans. I think the existence of humans was not inevitable, it was just a chance event. If you look at all the other current species, many non-human animals are quite successful. Humans are not necessary for their success, and in fact, humans have been responsible for the extinction of many interesting animals. It is easy to imagine an earth without humans.

Some precursor animal lived in an environment where mental ability was a major asset. So this species kept evolving better and better brains that led to more successful and likely reproduction.

Let’s fantasize an environment where high intelligence, instead of such traits as better legs for running, was important for survival. Suppose one such environment was characterized by several major changes in food supply. Perhaps a favorite plant or animal to eat became extinct. The adaptation to major changes in food source probably would require more brain power. There could also be major changes in climate or the availability of water. Perhaps in one region there were two pre-human species that were highly competitive for a limited supply of food. The smarter species could have been more able to survive, and more likely to pass its DNA on to future generations. A superior memory could help find water during a drought, or the location of food sources for different seasons.

Dinosaurs never developed big smart brains like ours during their many years of existence. This suggests it takes a certain DNA structure and a certain environment to initiate the evolution of this large adaptive brain. It may, in fact, be a very rare occurrence in the Universe, and we are just very lucky.

I have written the above to provide information in a short form that may be useful for those not wanting read thousands of book pages. It is an effort to present key facts that may be lost in a sea of writings. I also commend the thousands of dedicated scientists that have contributed to our understanding of this profound topic.