"CONSCIOUSNESS" (A PHYSICIST’S VIEWPOINT)

"CONSCIOUSNESS" (A PHYSICIST’S VIEWPOINT)

by : Aria Ratmandanu 

Figure 1. “The evolutionary history of the brain, with the reptilian brain, the limbic system (the mammalian brain), and the neocortex (the human brain). Roughly speaking, one can argue that the path of our brain’s evolution passed from the reptilian brain to the mammalian brain to the human brain”

“The descriptions of consciousness in the fields of neurology and biology in order to define consciousness as follows:

"Consciousness is the process of creating a model of the world using multiple feedback loops in various parameters (e.g., in temperature, space, time, and in relation to others), in order to accomplish a goal (e.g., find mates, food, shelter)."

      I call this the “space-time theory of consciousness,” because it emphasizes the idea that animals create a model of the world mainly in relation to space, and to one another, while humans go beyond and create a model of the world in relation to time, both forward and backward.

    For example, the lowest level of consciousness is Level 0, where an organism is stationary or has limited mobility and creates a model of its place using feedback loops in a few parameters (e.g., temperature). For example, the simplest level of consciousness is a thermostat. It automatically turns on an air conditioner or heater to adjust the temperature in a room, without any help. The key is a feedback loop that turns on a switch if the temperature gets too hot or cold. (For example, metals expand when heated, so a thermostat can turn on a switch if a metal strip expands beyond a certain point.)

                    Each feedback loop registers “one unit of consciousness,” so a thermostat would have a single unit of Level 0 consciousness, that is, Level 0:1. In this way, we can rank consciousness numerically, on the basis of the number and complexity of the feedback loops used to create a model of the world. Consciousness is then no longer a vague collection of undefined, circular concepts “but a system of hierarchies that can be ranked numerically. For example, a bacterium or a flower has many more feedback loops, so they would have a higher level of Level 0 consciousness. A flower with ten feedback loops (which measure temperature, moisture, sunlight, gravity, etc.), would have a Level 0:10 consciousness.

             Organisms that are mobile and have a central nervous system have Level I consciousness, which includes a new set of parameters to measure their changing location. One example of Level I consciousness would be reptiles. They have so many feedback loops that they developed a central nervous system to handle them. The reptilian brain would have perhaps one hundred or more feedback loops (governing their sense of smell, balance, touch, sound, sight, blood pressure, etc., and each of these contains more feedback loops). For example, eyesight alone involves a large number of feedback loops, since the eye can recognize color, movement, shapes, light intensity, and shadows. Similarly, the reptile’s other senses, such as hearing and taste, require additional feedback loops. The totality of these numerous feedback loops creates a mental picture of where the reptile is located in the world, and where other animals (e.g., prey) are located as well. Level I consciousness, in turn, is governed mainly by the reptilian brain, located in the back and center of the human head.”

            Next we have Level II consciousness, where organisms create a model of their place not only in space but also with respect to others (i.e., they are social animals with emotions). The number of feedback loops for Level II consciousness explodes exponentially, so it is useful to introduce a new numerical ranking for this type of consciousness. Forming allies, detecting enemies, serving the alpha male, etc., are all very complex behaviors requiring a vastly expanded brain, so Level II consciousness coincides with the formation of new structures of the brain in the form of the limbic system. As noted earlier, the limbic system includes the hippocampus (for memories), amygdala (for emotions), and the thalamus (for sensory information), all of which provide new parameters for creating models in relation to others. The number and type of feedback loops therefore change.

           We define the degree of Level II consciousness as the total number of distinct feedback loops required for an animal to interact socially with members of its grouping. Unfortunately, studies of animal consciousness are extremely limited, so little work has been done to catalog all the ways in which animals communicate socially with one another. But to a crude first approximation, we can estimate Level II consciousness by counting the number of fellow animals in its pack or tribe and then listing the total number of ways in which the animal interacts emotionally with each one. This would include recognizing rivals and friends, forming bonds with others, reciprocating favors, building coalitions, understanding your status and the social ranking of others, respecting the status of your superiors, displaying your power over your inferiors, plotting to rise on the social ladder, etc. (We exclude insects from Level II, because although they have social relations with members of their hive or group, they have no emotions as far as we can tell.)

          Despite the lack of empirical studies of animal behaviors, we can give a very rough numerical rank to Level II consciousness by listing the total number of distinct emotions and social behaviors that the animal can exhibit. For example, if a wolf pack consists of ten wolves, and each wolf interacts with all the others with fifteen different emotions and gestures, then its level of consciousness, to a first approximation, is given by the product of the two, or 150, so it would have Level II:150 consciousness. This number takes into account both the number of other animals it has to interact with as well as the number of ways it can communicate with each one. This number only approximates the total number of social interactions that the animal can display, and will undoubtedly change as we learn more about its behavior.

           Of course, because evolution is never clean and precise, there are caveats that we have to explain, such as the level of consciousness of social animals that are solitary hunters. 

              With this framework for consciousness, we see that humans are not unique, and that there is a continuum of consciousness. As Charles Darwin once commented, “The difference between man and the higher animals, great as it is, is certainly one of degree and not of kind.” But what separates human consciousness from the consciousness of animals? Humans are alone in the animal kingdom in understanding the concept of tomorrow. Unlike animals, we constantly ask ourselves “What if?” weeks, months, and even years into the future, so I believe that Level III consciousness creates a model of its place in the world and then simulates it into the future, by making rough predictions. We can summarize this as follows:

                Human consciousness is a specific form of consciousness that creates a model of the world and then simulates it in time, by evaluating the past to simulate the future. This requires mediating and evaluating many feedback loops in order to make a decision to achieve a goal.

         By the time we reach Level III consciousness, there are so many feedback loops that we need a CEO to sift through them in order to simulate the future and make a final decision. Accordingly, our brains differ from those of other animals, especially in the expanded prefrontal cortex, located just behind the forehead, which allows us to “see” into the future.”

“We summarize these levels of consciousness in the following diagram:

“Space-time theory of consciousness. We define consciousness as the process of creating a model of the world using multiple feedback loops in various parameters (e.g., in space, time, and in relation to others), in order to accomplish a goal. Human consciousness is a particular type that involves mediating between these feedback loops by simulating the future and evaluating the past.”

“LEVEL I: STREAM OF CONSCIOUSNESS”

        “Humans are probably alone on this planet in being able to operate on all levels of con”“sciousness. Using MRI scans, we can break down the different structures involved in each level of consciousness.

           For us, Level I stream of consciousness is largely the interplay between the prefrontal cortex and the thalamus. When taking a leisurely stroll in the park, we are aware of the smells of the plants, the sensation of a gentle breeze, the visual stimuli from the sun, and so on. Our senses send signals to the spinal cord, the brain stem, and then to the thalamus, which operates like a relay station, sorting out the stimuli and sending them on to the various cortices of the brain. The images of the park, for example, are sent to the occipital cortex in the back of the brain, while the sense of touch from the wind is sent to the parietal lobe. The signals are processed in appropriate cortices, and then sent to the prefrontal cortex, where we finally become conscious of all these sensations.”

         “While Level I consciousness uses sensations to create a model of our physical location in space, Level II consciousness creates a model of our place in society.

          Let’s say we are going to an important cocktail party, in which people essential to our job will be present. As we scan the room, trying to identify people from our workplace, there is an intense interplay between the hippocampus (which processes memories), the amygdala (which processes emotions), and the prefrontal cortex (which puts all this information together).

Figure 2. “In Level I consciousness, sensory information travels through the brain stem, past the thalamus, onto the various cortices of the brain, and finally to the prefrontal cortex. Thus this stream of Level I consciousness is created by the flow of information from the thalamus to the prefrontal cortex”

LEVEL II CONSCIOUSNESS

         “ With each image, the brain automatically attaches an emotion, such as happiness, fear, anger, or jealousy, and processes the emotion in the amygdala. If you spot your chief rival, whom you suspect of stabbing you in the back, the emotion of fear is processed by the amygdala, which sends an urgent message to the prefrontal cortex, alerting it to possible danger. At the same time, signals are sent to your endocrine system to start pumping adrenaline and other hormones into the blood, thereby increasing your heartbeat and preparing you for a possible fight-or-flight response.”

           “But beyond simply recognizing other people, the brain has the uncanny ability to guess what other people are thinking about. This is called the Theory of Mind, a theory first proposed by Dr. David Premack of the University of Pennsylvania, which is the ability to infer the thoughts of others. In any “complex society, anyone with the ability to correctly guess the intentions, motives, and plans of other people has a tremendous survival advantage over those who can’t. The Theory of Mind allows you to form alliances with others, isolate your enemies, and solidify your friendships, which vastly increases your power and chances of survival and mating. Some anthropologists even believe that the mastery of the Theory of Mind was essential in the evolution of the brain.”

Figure 3. “Emotions originate and are processed in the limbic system. In Level II consciousness, we are continually bombarded with sensory information, but emotions are rapid-fire responses to emergencies from the limbic system that do not need permission from the prefrontal cortex. The hippocampus is also important for processing memories. So Level II consciousness, at its core, involves the reaction of the “amygdala, hippocampus, and prefrontal cortex”

LEVEL III CONSCIOUSNESS

        But how is the Theory of Mind accomplished? One clue came in 1996, with the discovery of “mirror neurons” by Drs. Giacomo Rizzolatti, Leonardo Fogassi, and Vittorio Gallese. These neurons fire when you are performing a certain task and also when you see someone else performing that same task. (Mirror neurons also fire for emotions as well as physical acts. If you feel a certain emotion, and think another is feeling that same emotion, then the mirror neurons will fire.)

           Mirror neurons are essential for mimicry and also for empathy, giving us the ability not only to copy the complex tasks performed by others but also to experience the emotions that person must be feeling. Mirror neurons were thus probably essential for our evolution as human beings, since cooperation is essential for holding the tribe together.”

         Mirror neurons were first found in the premotor areas of monkey brains. But since then, they have been found in humans in the prefrontal cortex. Dr. V. S. Ramachandran believes that mirror neurons were essential in giving us the power of self-awareness and concludes, “I predict that mirror neurons will do for psychology what DNA did for biology: they will provide a unifying framework and help explain a host of mental abilities that have hitherto remained mysterious and inaccessible to experiments.” (We should point out, however, that all scientific results have to be tested and reconfirmed. There is no doubt that certain neurons are performing this crucial behavior involved with empathy, mimicry, etc., but there is some debate about the identity of these mirror neurons. For example, some critics claim that perhaps these behaviors are common to many neurons, and that there is not a single class of neurons dedicated to this behavior.)

           The highest level of consciousness, which is associated primarily with Homo sapiens, is Level III consciousness, in which we take our model of the world and then run simulations into the future.

      

Figure 4. “Simulating the future, the heart of Level III consciousness, is mediated by the dorsolateral prefrontal cortex, the CEO of the brain, with competition between the pleasure center and the orbitofrontal  cortex (which acts to check our impulses). This roughly resembles the outline given by Freud of the struggle between our conscience and desires. The actual process of simulating the future takes place when the prefrontal cortex accesses the memories of the past in order to approximate future events.”