Tuesday, December 26, 2023

The Mind: Who you are at any given moment.

What is the mind? It is elusive, and it is the product of conscious awareness, which is a product of the brain. The mind is the sum total of all the information you are aware of at any point in time, whether it be a song, a thought, a full moon, whatever you happen to be cognizant of at any given moment. Everyone’s mind is different because the way we see the world depends on our past experiences, and our physical makeup. All senses combine to make up the mind, so if you press your foot against the floor your foot becomes part of your mind. Your mind is who you are at any given moment. A neural network forms a memory system that keeps your mind familiar when it becomes instantiated into conscious awareness. Call the core processes a personality. Your brain goes to great lengths to keep your mind together mainly by discarding the vast majority of the information our sensory systems take in; for example, the visual sensory system processes about 10,000,000 bits per second, while our thought rate is only 40 bits per second.

In 1909 a man ahead of his time, named Jakob von Uexküll, coined the term umwelt to represent the perceptive mass of any species. In the same environment each species has its own unique viewpoint i.e. umwelt. Worlds within worlds. What do blue birds see, or feel? Are they conscious? What is their umwelt? Certainly, all primates are conscious, they feel pain, they solve problems, and they have minds. Part of our umwelt is what we think of course. If you take that away most humans umwelten (the plural of umwelt) are probably very similar. In our umwelt we share emotions, and we are thinking machines. Let’s delve into the mind.


Nobel Laureate Eric Kandel pointed out two startling ramifications about vision. 

1. We do not have direct access to the real world.

2. Vision is not a window on the world but a creation of the brain.


In a very brief overview, a 2D image on the retina is converted into a 3D image in the brain. Once visual information in the eye has been transduced and reaches the optic nerve it soon arrives at the visual cortex where contrast, color and motion are analyzed in different regions of the cortex. Information is sent forward where, for example, contours are analyzed, and the foreground is separated from the background. Object recognition uses memory in the temporal lobe as part of the ventral ‘what’ pathway that identifies the object. Simultaneously information is sent to the dorsal ‘where’ pathway in the parietal lobe to determine the object’s location in space. As Kandel pointed out, the key to visual processing is that the image that we see has been constructed for us by our brains. This general concept applies equally to all sensory systems. Our brain constructs what we see, hear, smell, taste, and touch.


When I was a child, my mother brought me to a smoke-filled college auditorium to see the Beatles’ movie Yellow Submarine. About halfway through the animated feature there was a lull in the action, and I turned to my mother and said, “I feel funny.” The entire theatre broke out laughing, quite proud to have gotten a five-year-old stoned. Hey, it was the sixties. I remembered George Harrison’s character saying, ‘It’s all in your mind.’ I did not understand what he meant until many years later while I read Walden by Henry David Thoreau. Knowing that our brains constructed our world brought home the idea that everything I sensed was a creation of my mind as Kandel implied. At the time I became convinced that George Harrison was right. It was all in my mind.


That leaves me at Caltech where I met Steven Hawking after a seminar of his on the birth of the universe. I did say we met. Well, we didn’t exactly meet in the traditional sense, instead Hawking ran over my foot with his electric wheelchair. I wasn’t watching out; I made my profuse apologies and Hawking smiled broadly and then scooted away. That incident didn’t trouble me about Steven Hawking, but when he later wrote about a table in a room that stays in the room even after you leave troubled me greatly. Why was he writing about tables? Then it hit me. I was devastated. If everything was in my mind, why didn’t the world change when I didn’t watch it? Why didn’t my computer turn into a tomato when I was away from my desk? If I look away, my computer monitor remains in front of me when I look back: every single time! There must be a memory source outside of my mind! Tables! What this memory source looks like or feels like is impossible to say because what I experience is in my mind. In fact, it is my mind.


Hold on to your hats. Now I ask you a simple question; where is the image of the words you are now reading? Take a moment…clearly the answer is inside your mind. Look around your room and see that it too is inside your mind. All you will ever see is constructed inside your mind. Memories alter what you see and work very hard keeping your act together. The whole world just got even more subjective. The mind externalizes our senses so that the world is out there, and to help situate yourself in that world. 


David Chalmers first formulated the so-called hard problem of consciousness, that is, how are electrochemical signals in the brain converted into actual experiences such as pleasure and pain? That’s opposed to easy questions such as what neurotransmitters affect a cognitive state. I believe a definition such as a ‘state of focused awareness’ captures the important aspects of consciousness including self-awareness. The other is that consciousness is the act of experiencing qualia. Qualia are just experiences such as seeing blue, tasting chocolate, hearing a piano, etc. Another big question is what material is the mind made of. Surely it has a neuronal electrochemical basis, but how is this transformed into a flaming red Maple tree in autumn or the taste of a Lemon Meringue pie? Both of which are products of the mind. If a Maple falls in the woods and nobody is there to hear it, does it make a sound? No! Only minds make sounds, falling trees make air waves. Considering von Uexküll’s umwelt, what would an ant think of a towering maple tree? Which is the right umwelt? Whose world is the real world? According to Kandel, we don’t get to see the real world; our reality is a construct full of biases and memory driven inconsistencies.  


At one time in my life between my Walden elation and Hawking deflation I thought everything was in my mind. Now I ascribe to the memory system of the universe. How else could the logic of the world stay so normal? Normal in the sense that a table remains a table when no one is looking. Actually, it doesn’t remain a table, that is a mind made object, what remains is the memory system that collaborates with the brain to instantiate a table only when it is gazed upon or felt. What can we say about this memory source? I like the name source as in the source of our minds, but I do not imply any religious significance. The main point is that everywhere I look, hear, smell, touch, and taste I am confronted with my mind which has been constructed by my brain from the emissions of sources, such as light or I should say pre-light (photons), as light is a product of the mind. For example, you are walking along in your bare feet thinking about what to have for dinner when suddenly you stub your toe. Ouch! Prior to stubbing your toe, your toe was not part of your mind, but immediately afterwards your toe’s ‘pain’ neurons send a signal to your brain, which are then instantiated into the sensation of pain creating your toe in your mind. Prior to instantiation in your mind your toe was source. We can describe our worlds and infer what source must be doing based on observations and throw science at it continually bringing the unknown to the known, and darkness into the light of our minds. More on source in a future blog post, and its implications on the universe as a potential computer or even a simulation.


Further reading: 

David Chalmers (1995). "Facing up to the problem of consciousness." Journal of Consciousness Studies. 2 (3): 200–219. 

Eric Kandel (2012). “The Age of Insight.” Random House.

Eric Kandel, John D. Koester, Sarah H. Mack, Steven Siegelbaum (2021). “Principles of Neural Science, 6th Edition.” McGraw Hill.

Donald Hoffman (2019). “The Case Against Reality.” Penguin.

Tor Norretranders (1999). “The User Illusion.” Penguin.


Monday, December 18, 2023

Liquid Brains: A Different View of Intelligence

Liquid brains are the distributed and dynamic ways of information processing in social insect colonies, slime molds, bird flocks, fish schools, and even the immune system. Unlike solid brains, which are fixed in size and shape, liquid brains can change their volume and form depending on the situation. Liquid brains are composed of individuals that act as neurons, transmitting signals through their interactions with each other and the environment. Liquid brains can also store and retrieve memories, coordinate tasks, learn from experience, and adapt to changing conditions without a central leader or a centralized sophisticated brain. 


Solid brains, such as the human brain, exhibit what is termed a small-world architecture. That is most connections are local in nature, while some are not, and these long-range connections carry the group consensus to other portions of the brain. These long-range nerve tracts the so-called rich club are the most active in the brain, and they are particularly good for quick solutions to problems. But if the quick response is met with negative feedback, then a more elegant solution is required and searching among the local small-world component neurons takes place until a new more accurate consensus is reached. The same phenomenon occurs with liquid brains. In bees for example, there is a rich club of individual bees who are termed elites that function at a significantly higher level than the average hive mate and it is this rich club of bees that serve to best find food sources and potential new hive sites, which are then searched by local small-world bees that follow the elite’s instructions that are dictated by a waggle dance (see below).


Decisions are ultimately made by quorum sensing, an emergent phenomenon of greater intelligence than that of the individual bees. Quorum sensing is a democratic process in which individual agents, such as bacteria, fungi, insects, and even neurons in monkey brains communicate with each other and coordinate their actions based on the number and quality of signals they receive from their peers until a quorum level of consensus (say 80% in agreement) is reached. Once the consensus has been reached the group takes the appropriate action. It is an amazing example of how animals can achieve complex and intelligent outcomes without a central authority or leader. By using simple rules and local interactions, they can solve problems that require collective wisdom and consensus. Quorum sensing also shows how nature can inspire new solutions for human challenges, such as distributed computing, network optimization, and social coordination.


You might be asking yourself, “Don’t social insects like bees and ants have Queens?” They do, but they are not part of the executive functions such as decision making, instead they are relegated to mating and egg laying, for which they may lay up to 2 million eggs in their lifetime in some species.


Liquid brains are themselves an example of an emergent phenomenon where the capabilities of the whole are greater than the sum of its parts. Emergent phenomena such as the development of a multicellular embryo proceeds without a leader, an executive, and the embryo as a whole is also greater than the sum of its parts. Thus, emergence can be defined as a Gestalt that leads to a dramatic decrease in description length. To paraphrase Sean Carroll the uncountable number of quantum interactions going on in front of me can be reduced into a single word a table.


One way to understand the intelligence of liquid brains is the ability of a group of individuals to solve problems that are beyond the capabilities of a single individual. These emergent properties are self-organized and robust. They rely on positive and negative feedback mechanisms that regulate its dynamics. For example, if a food source is discovered by a scout bee, it will return to the hive and perform a waggle dance that indicates the direction and distance of the food. The vigor and length of the dance indicates the quality of the food source. The more bees that visit the food source, the more they will recruit others, creating a positive feedback loop that amplifies the signal. However, if the food source becomes depleted or less attractive, the bees will stop visiting it and stop recruiting others, creating a negative feedback loop that dampens the signal. This way, the group as a whole can allocate its resources efficiently and avoid wasting time and energy on unprofitable options.


Finally, one of the most striking examples of how a liquid brain functions is the process of nest-site selection in honeybees. When a colony needs to relocate to a new nest site, such as when it swarms or when its current nest is destroyed, it faces a complex decision problem that involves multiple nest criteria, such as the size, shape, orientation, entrance size, cavity volume, insulation, etc. First, a small fraction of the colony (about 5%, elites), act as scouts that search for potential nest sites in the surrounding area. Each scout evaluates a site based on its own criteria and preferences and returns to the swarm cluster to report its findings. The scout performs a waggle dance that encodes the quality and location of the site. Second, each scout that visits a site compares it with other sites that it has visited before, by the amount and quality of the waggle dancing that is currently going on for the alternative sites. Finally, as more scouts visit more sites and exchange more information, a collective preference emerges among them. Eventually, one site will gain enough support from enough scouts to reach a quorum sensing threshold that triggers a decision. The scouts that have agreed on this site will then stop dancing and start producing a piping sound that signals their readiness to move. The piping sound will spread throughout the swarm cluster and induce the other bees to follow the elites to their new home.


Liquid brains challenge our conventional notions of intelligence and cognition, showing that complex behaviors can emerge from simple interactions among many agents. Liquid brains are truly amazing in their abilities, without a central leader, to perform higher-level cognitive functions, such as decision making, memory storage and retrieval, asset allocation, learning from experience, and adapting to novel stimuli and environments.


Further reading:

Stephen Buchmann (2023) What a Bee Knows. Island Press.

György Buzsáki (2019). The Brain from Inside Out. Oxford University Press. 

Seeley, T.D., Visscher, P.K., Schlegel, T., Hogan, P.M., Franks, N.R., & Marshall, J.A.R. (2007). Stop signals provide cross inhibition in collective decision-making by honeybee swarms. Science, 335(6064).

Solé R, Moses M, Forrest S. (2019). Liquid brains, solid brains. Philos Trans R Soc Lond B Biol Sci. Jun 10; 374(1774).

Tuesday, December 5, 2023