Memories in both the brain and mind are organized in nested hierarchical networks. This all seems rather conventional and boring until we start to inquire about how these memory structures link to our consciousness. What we find is we have not left the Looking Glass at all, but only gone deeper into it.
Contents for The Yogic View of Consciousness:
|Intro||Ch 1||Ch 2||Ch 3||Ch 4||Ch 5||Ch 6||Ch7||Ch 8|
|Ch 9||Ch 10||Ch 11||Ch 12||Ch 13||Ch 14||Ch 15||Ch 16||Ch 17|
|Ch 18||Ch 19||Ch 20||Ch 21||Ch 22||Ch 23||Ch 24||Ch 25||Ch 26|
|Ch 27||Ch 28||Ch 29||Ch 30||Ch 31||Ch 32||Ch 33|
We’re now exploring the Cave of Consciousness. The last chapter introduced the idea that our conscious behavior is molded by unconscious factors operating at many levels. Our body, brain, past experiences, and socially-programmed behaviors are obvious contributors. Buried under these, however, is the rest of the universe. Leibniz was essentially correct about everything reflecting everything else. In Kaivalya this is all goodness and light. In Manifestation it is so disguised in a most abstract fashion as to become hidden in what the West has come to recognize as the “unconscious mind”. Yoga calls the hidden stuff samskaras. We’re still not quite ready to discuss Freud, Jung and samskaras yet; we’ll get to that next time.
We’re building a picture about the unconscious mind in stages. The previous chapter talked about how most of what the brain does is unconscious. In this chapter we link the unconscious to memory. The structures of the unconscious mind are memories. We now discuss the structure and function of memory. Memories form networks in our minds. These networks act like invisible screens, sieves, and filters through which are projected our conscious perceptions, thoughts, emotions, and actions.
The Neuroscience of Memory
Last time, Bernard Baars’ book The Cognitive Theory of Consciousness was introduced. This book constructs a theory of the mind called the Global Workspace theory. It is a very nice theory, but I have no intention of going into all of it here (reads Baars book if you want to learn the theory). There is, however, a key aspect of the theory relevant to the present discussion. Baars introduces an idea he terms “contexts”. By this he is referring to higher order memory patterns found in the mind. Baars’ idea explains the structure and function of memories and how they unconsciously affect conscious experience. Before getting to Baars’ idea, it is helpful to first discuss the current understanding of memory in the neurosciences. There are three types of memory commonly recognized in the neurosciences. These have been discovered through a combination of psychology studies, neurology studies of brain‑damage people, and animal experiments. A quick summary is the following:
Declarative memories. These are our memories of things we know (called semantic memories) and of our past experiences (called episodic memories). They are formed in the brain by a structure called the hippocampus, in association with other brain regions in the medial temporal lobe. They are called “declarative” because we can declare them by talking about them. However, any animal with a hippocampus has declarative memories, but only humans can express such memories using speech. Damage to the hippocampus prevents formation of new declarative memories. Declarative memories are stored in the cerebral cortex, in those parts responsible for the associated function. That is, visual memories are stored in visual cortex, language memories are stored in Wernicke’s area, and so on. Destruction of cortex leads to loss of these memories giving rise to conditions called in neurology agnosias, aphasias, and so on.
Procedural memories. These are all the things we know how to do with our (skeletal) muscles, commonly called “muscle memory”. Examples of procedural memories include walking, talking, riding a bike, driving a car, playing a musical instrument, any sport activity…you get the drill. Procedural memories are expressed by actually moving muscles. There is no one brain region that causes them to form. Instead, the entire motor system in the brain and spinal cord contribute to forming this type of memory.
Working memory. This used to be called “short-term memory” in psychology. The term “working memory” derives from neurology, where brain damage that affects this type of memory has been studied by neurologists. The main brain region involved is the prefrontal cortex. Working memory includes the ability to hold memories before our mind’s eye for short durations (on the order of seconds), but it is much more than just this. Neurologists have discovered that people with damage to working memory either: (1) get stuck on a task and cannot stop, even if circumstances change, or (2) cannot stay focused on a task for an extended period of time. It is even subtler than this, however. In everyday life we use working memory to establish a behavioral set. This allows us to carry out extended goals or to adapt to changes in our environment. When working memory doesn’t function properly, people can no longer effectively carry out goals or adapt to changing circumstances.
All three types of memory are critical to our daily behavior. Dementia is the loss of declarative memory function, as seen for example in Alzheimer’s disease. Damage to procedural memories upset the ability to move properly, as seen in Parkinson’s or Huntington’s diseases. A number of conditions disrupt working memory, including stroke, chronic alcoholism (Korsakov’s syndrome), and head trauma, among others.
Strengths and Weaknesses
As with any scientific concept, there are strengths and weakness with this three-way classification scheme of memory. One weakness is particularly pertinent to our present discussion.
In neuroscience, declarative memories are associated with consciousness. We consciously recall them, and we have to be conscious to memorize them. Otherwise, we could learn by listening to books-on-tape when we sleep, which doesn’t work.
Procedural memories, on the other hand, are associated with unconscious, automatic behaviors like habits. As I said last time, we don’t have to think very much when we walk, or read, or even talk. We don’t have to think about the mechanics of these processes. The mechanics are invisible and thus allow us to focus on where we are going, the meaning of what we read, or what we wish to say. We reviewed reading in the previous chapter and saw that most of what happens, including at the cognitive level, is unconscious.
However, the simple associations of declarative/conscious and procedural/unconscious don’t work in practice. On one hand, we have to spend a great deal of conscious attention learning procedural memories. On the other hand, we saw with our iceberg picture that, once learned, many declarative memories sit in an unconscious state until they are consciously expressed.
Hence the neuroscience categorization of memory is not the end-all-be-all, or the last word on what memory is in our brain and mind. This is where Baars’ idea of “context” comes in.
Sidebar: Much can be said about how the brain is altered when learning occurs. This is the general topic of brain and neuronal plasticity. There is no need to get to this level of depth here. However, there is one thing worth pointing out in this regard. The mechanisms causally linking the high level cognitive memory functions we are discussing here to the low level cellular and brain plasticity are not known. Things like the various forms of potentiation, changes in synaptic release probabilities, and morphological changes in neurons have all been identified. How they relate to changes in conscious things is unknown. This is another facet of the qualia problem and will remain unsolved until the qualia problem is solved.
When Baars defined the unconscious as “that which affects conscious experiences without being conscious”, he had an idea about memory that is more subtle and sophisticated than the neuroscience ideas reviewed above. He realized that, regardless of the type of memory, all memory begins with conscious attention and practice, and then becomes unconscious over time, until the memories invisibly frame our conscious experiences. These invisible memory structures that come to frame our conscious experience, he calls “contexts”.
With his idea of “contexts”, Baars has identified a basic feature of brain function that went mostly unnoticed by the neurosciences through the 20th century and is still not widely appreciated now. Baars recognized that the brain uses consciousness to learn new information. As the information becomes learned, it somehow alters the brain so that the information becomes unconscious. In doing so, it alters consciousness experience.
Allowing learned information to become unconscious makes consciousness more effective. More effective at what? At whatever it is the brain has learned. It doesn’t matter if it is playing a musical instrument, learning science, learning a language, or whatever. One can even learn racism and prejudice. It just doesn’t matter what the content is. When the brain learns something effectively, that something eventually becomes unconscious. When the information is unconscious, it automatically shapes or molds consciousness making it much more effective with respect to whatever was learned. One learns to play the musical instrument more fluidly. One learns to do science more easily. One can be a racist more effectively by making it a habit.
How does this happen? Baars postulates that there is definite structure to how memories are organized in the brain and mind. The following are images from The Cognitive Theory of Consciousness illustrating how contexts unconsciously mold or shape conscious experiences.
On the left is a generic picture of how various memory networks form a hierarchical structure and compete for access to consciousness. The middle shows a specific goal context: the desire to buy ice cream. We can see that the goal to have ice cream emerges out of a series of increasingly general goals. Wanting ice cream springs from the goal to be comfortable, which sits in the goal to have self-esteem, which sits in the goal of avoiding pain and increase pleasure, which sits in the goal of surviving. As the goals get deeper, they are less conscious with respect to the task at hand, yet serve as platforms for the higher level goals. The right image shows the same logic applied to language production, i.e. speaking or writing. Here, the various layers of function combine to allow you to say “I like ice cream”. Again, all of this is mostly unconscious.
Using ice cream as an example should not fool the Reader. On one hand, these ideas are meant to explain our normal everyday behaviors. On the other hand, the generality of the ideas allows them to be applied to every facet of human behavior, from something as mundane as eating ice cream to something as profound as painting the Sistine Chapel. And yes, even to explain how yoga works, which is, to remind you, where we are going with all this.
Memories Form Nested Networks
Baars’ term “context” is potentially a point of confusion because the word “context” has several meanings. He uses the word in a specific technical sense to mean “memory patterns that are unconscious, yet shape conscious experience”. To avoid confusion, we will use the term “memory pattern” or “memory network” in place of his technical term “context”. Let us consider in some more detail the structure that Baars posits for how our unconscious mind is organized.
Please note I am now using the terms “unconscious” and “memory networks” almost synonymously. Because of what Baars has identified, we can safely link memories to unconscious processes. The memory networks are mostly unconscious, except when they explicitly enter consciousness, which is relatively rare for any given memory item. Instead memory items function to frame consciousness as nodes or elements of contexts.
The organization of our memories is described by three words: nested, hierarchical networks. Baars scheme above shows how our memories form nested structures. The brain is the network par excellence. Combining what we know of brain network structure with Baars theory shows us the structure of how memories are organized.
Pictures help. Let’s start simple:
The various qualitative types of memory are relatively autonomous because they are localized to specific areas of the brain. Sensations are mediated by their specific pathways and corresponding sensory cortices. Emotions emerge out of the collective action of the hypothalamus, nucleus accumbens (this is the “dopamine pleasure center” some of you may have heard of), amygdala, and parts of the prefrontal cortex and temporal lobe. Voluntary goal-directed behavior is mainly localized to the prefrontal cortex. Learned declarative information resides in association cortices and higher order sensory cortices.
However, all of the brain regions are interconnected via axonal tracts (white matter). Therefore it’s one big network in the brain.
Here is a slightly more complicated view of the organizational pattern:
This is the same drawing as Figure 2, just with some details filled in. Sensory perception involves the five senses everyone knows about, and a myriad of other senses that are not common knowledge (i.e. glucose sensors in your GI tract, or blood pressure sensors in your aorta). Emotions are always attractive or repulsive, but there are myriad shades of them. The semantic and episodic networks can be broken out and further subdivided way beyond what is indicated here. The nested structure of goals is illustrated by Baars’ picture in Figure 1, but goals are also networked. Goals network amongst themselves (i.e. wanting a better life is, for many people, coupled to the goal of going to college, for example), and also to the rest of the mind’s functions, like sensation, cognition, etc.
I cannot illustrate the full complexity of this system. The diagram would be incomprehensibly complex if every nested function and link was attempted to be depicted. The point is to get a general idea of how our memories are organized. Again: nested, hierarchical networks.
How Does This System Work?
Having sketched the structure, let’s now discuss the function of this system. First it is worth asking: what is this a system of?
Prior to the advent of computers, memory was more elusive to define. It could be understood as a representation of the past that exists in the present. This is true, but ambiguous, and not very precise. Today, we all know about information, and so we can understand memory easily. Memory is stored information. Whoopty doo. We all have computers with hard disks and we have USB drives in our pockets. Today, everyone knows what memory is in very concrete terms.
Now, we can speak of “information patterns” stored in our brain and mind, but how these are concretely linked is, as I said above, not known. Again, the qualia problem. But the fact is, we don’t need to know this to proceed in a useful fashion. We can talk about brain networks or mind networks as circumstances dictate. In the present circumstances, we are interested in the mind networks such as illustrated by the figures above.
Our question is: what does this system do? This too was an elusive question until Baars put forth his theory. His theory is, in my opinion, our present best guess as an answer to this question.
The information structures that we call “memory” serve to filter, direct, shape, and mold, our conscious experiences. They are like stained glass that colors the white light passing through it. Our memories give shape and substance to the various domains in which we act. But the memories are mostly unconscious. But they mold our consciousness.
What this means is that our conscious experiences are a manifestation of the structures of the nested hierarchy of memories. It is a very strange idea, hard to express in words. Several different words come to mind: consciousness is a projection, a shadow, a manifestation of, a reflection of, an encoding of the unconscious information patterns.
What I am saying is that what is conscious and what is unconscious are intimately related. Like mirror images in a sense. It is a very strange insight. Normally conscious and unconscious are considered exact opposites. But they are not. Each contains the other.
Perhaps the most useful term is “encoded”: the unconscious information patterns are encoded in our conscious experiences.
How deep does this go?
We’ll address this question in the next chapter, but let’s make a first pass now.
As we saw previously, the structures of our brain give rise to seeing, to reading, and to language recognition. Where does the memory end and the biology begin? By this I mean, we have unconscious memory patterns that allow us to recognize words and objects. These are clearly memories in the conventional sense. But other unconscious processes are due to the very structure of the eye and brain. Light interacting with the rods and cones of the retina is unconscious, but can it also be considered a memory? It doesn’t seem like it on first hearing. Similarly, electricity flowing up the optic nerve is unconscious, but is it a memory? Again, doesn’t seem like. But the electricity goes into the brain and activates patterns of electricity in the neurons there. Is this a memory? Well, now it seems like it is.
With a USB drive or hard drive we can clearly demarcate the storage medium from the information stored on it. However, it is not so clear with the brain and memories. In fact it is totally unclear. We know the mechanism of how information is stored on a USB drive. We have no idea whatsoever scientifically of the link between brain biology and mental experiences. We can pretend the brain is like a hard drive and simply stores information, but this a lame analogy that gives short shrift to the brain. The neural correlates of consciousness are just that: correlations. Every real scientist knows that correlation does not equal causation.
Therefore, we cannot simply assume that the brain is a hardware device that stores patterns of information analogous to our computer technology. In the case of the brain, the stored information (memories) alters the “hardware” (the brain) which in turn alters the “software” (the mind).
Where does the biology end and the information processing begin? What is the link between conscious and unconscious stuff? Where does the memory end and the physical process begin? They certainly have one thing in common: movement. Otherwise known as “gunas” in yoga.
We are coming now to the heart of the matter of the Cave Of Consciousness.
The astute Reader will recall from Chapter 10 the section entitled “‘Being is Awareness’ is a Tautology”. There I discussed how samadhi is a fusion of the mind of the yogi with a memory in the mind of the yogi. We are positioning ourselves to understand that this is not as trivial as it seems at first glance. There is a strange link between conscious/unconscious and unconscious/memory that moves us into a domain of understanding that will take us quite out of the convention framework we have discussed in this and the last chapter, and move us back into the strange abstractions of yogic cosmology. But what we have accomplished in the meantime is to begin to link our normal everyday first hand experience to the mysteries that underlie samadhi.
We are moving towards understanding the modus operandi of samadhi. Please join me soon in Part 21 where we continue to expose this new level of strangeness.