Hierarchical Brain

Consciousness

Consciousness is a multi-faceted phenomenon that allows me to be aware of who and what I am, to think about what I am aware of and what I am doing, and to remember what I have done. These functions evolved because they provide a tremendous advantage for survival.

Consciousness is an exclusively personal experience and cannot be independently examined or tested; this makes it very difficult to investigate or explain using conventional scientific methods. Many theories have been put forward: some are unconventional and some do not really explain anything at all; and some people think it is not possible to explain consciousness without resorting to supernatural powers or as-yet-undiscovered laws of physics.

My hierarchical explanation of the workings of the brain using many levels of description, of which consciousness is at the highest at level 7, provides an explanation: my brain builds and maintains many symbol schemas that are representations of concepts and things in the world including of my body and my brain processes; what I call consciousness is the result of my conclusion that I am my self symbol schema, and that my self symbol schema is only aware of itself and other parts of the model of my world.

My personal experiences of consciousness

• The term consciousness has different meanings to different people in different contexts, but the following five interdependent features are what I experience and what I believe defines my consciousness. (I have deliberately not included any links to other pages of mine in this section because this is simply what I am aware of by introspection, but I have included some Wikipedia links).
  1. Self-awareness is my ability to think of myself as a separate entity, being the entity that is attending to a subject and having an experience.
     • Self-awareness is clearly a basic and absolute prerequisite for all other facets of consciousness.
  2. Attention is the flow of my thoughts (when I am awake) from one thing to another, either by my own choice or when something unexpected attracts my attention.
     • My attention can be either on things external to the brain, or on internal things, and internal things can be real events or situations from my memories or potential events or situations based on my existing knowledge.
     • Attention is the most obvious facet of consciousness that I am, or can be, aware of from moment to moment; without it I would not be able to say I was conscious.
     • My attention almost always involves self-awareness - if I don’t attend to something, I do not (and cannot) remember it - so attention with self-awareness is the only way in which memories of past events (episodic memories) are laid down or recalled.
     • However, I can still drive a car (reasonably safely) when my conscious attention is not on my driving, because, for example, I am talking to someone else or listening to the radio. So I feel that there is some level of attention going on even when I am not aware of it.
  3. Feelings and emotions are also an integral part of my consciousness, and without them I could not say I was fully conscious.
     • Feelings seem to be attached to almost anything and I have very little control over them (some people call these qualia).
     • Emotions are special types of feelings that are associated with changes within my body, but sometimes changes in my body occur before I am aware of the emotion.
     • Meaning seems to be closely related to feeling, and feelings are often connected to meaning.
     • Pain is very similar to an emotion, except that it is clearly triggered in my body, outside my brain.
  4. Memories are crucial to consciousness. Without being able to recall past memories or lay down new ones, my self-awareness would not be continuous and I would not feel that I had a continuing existence (sometimes called “transtemporal identity”).
     • Both newly-made and recalled (episodic) memories always have a link to “me”, otherwise they are not my memories.
     • The recall of memories of past events often recalls or reproduces, at least to some extent, the feelings and emotions of what I originally experienced.
  5. My consciousness is an integrated experience; I experience things as a unity, not in different bits associated with different senses or different times. This is a quality of consciousness rather than a feature of it, so perhaps is in a different category from the four items above, but it is nevertheless a crucial feature, and one that needs an explanation.

My explanation of my experiences

• My explanations of these five areas of my experiences of consciousness depends upon the whole of the hierarchical structure that is explained on this website. I have provided links to the relevant pages below.
  1. Self-awareness is enabled by the existence of the self-referential self symbol schema that is a model of my body and the processes of my brain.
     • The self symbol schema is created by the brain in early childhood using exactly the same method of afferent processing that is used to process incoming sense data, but the data in this case is from the body and from within the brain itself.
     • When I refer to “I”, the model is both the subject that is doing the referring and the object that is being referred to - I am my self symbol schema.
  2. Attention is a physical process of competition and selection created by lateral inhibition between groups of neurons as part of the processing of data by the brain.
     • I am aware of the end result of attention being the thing that I am attending to, but I cannot be aware of the processing that goes on prior to that result.
     • Self-awareness also allows me to know that I am aware of what I am attending to, and I can also be aware of the feeling of attending to something (see section on feeling below).
     • Attention with self-awareness is the only way in which memories of past events (episodic memories) are laid down so that they can be recalled at a later time. This is a major evolutionary advantage for survival.
     • Attention without self-awareness is possible, but only to a limited extent.
     • The process of attention on an object or concept creates a self-sustaining circuit of activated neurons, encompassing the self symbol schema and the symbol schema for the object or concept, causing oscillations that can last for several seconds.
     • To give an example of this using the notation I have proposed for symbol schemas, when I consciously perceive a frisbee, both {frisbee} and {self} are activated, and connections between these two created by the process of attention form a self-perpetuating neuronal circuit that lasts until this circuit is inhibited when the process of attention selects something else (this is how my thoughts flow from one thing to another).
     • In effect, the symbol schema for the object or concept becomes temporarily part of the self symbol schema.
  3. Feelings and emotions are involuntary additions to my self-awareness of a particular symbol schema caused by efferent connections from that symbol schema to others and then by reinstatement from any or all of them.
     • I include qualia, meaning and pain in the same category as feelings, because they are all brought about by the same processes.
     • Emotions are feelings that that are associated with changes within the body either as a result of a present experience or as a reinstatement of feelings related to a memory.
     • Feelings, emotions, qualia, meaning and pain relating to a thing only come about when I am conscious of that thing, which means that the process of attention has made a connection between the symbol schema for the thing and the self symbol schema.
     • Emotions can have an effect on the body before they reach consciousness, but, generally, as soon as become aware of the change in my body, it brings to my attention the thing that has caused it.
     • Reinstatement adds further self-sustaining networks of activations of neurons to the existing oscillations of attention. In effect, these feelings also become part of the self symbol schema.
  4. Memories are the recall of past events by the process of attention on already-existing symbol schemas.
     • This causes the reactivation or reinstatement of sensory neurons that were activated when the memory was first laid down.
     • This applies to both external and internal senses, so reinstatement can reproduce, to some extent, the sense, feelings and emotions of what was originally experienced.
     • Self-awareness allows me to be aware of these memories and feelings, and I can also know that I am aware of them. When they are laid down, they link to my self symbol schema and that link is still there when I recall them, so I can be aware that the memories are mine.
     • It is notable that implicit or procedural memories, such as how to ride a bicycle, do not feel so much like part of me, the links to my self symbol schema of memories of when I was learning the skill are no longer accessible.
  5. The unity of consciousness, which is a quality that applies to attention, feelings, and memory, comes about because my awareness is only of symbol schemas, not of reality.
     • Attention is the process that makes any perception, feeling or memory conscious by creating temporary connections from a particular symbol schema that represents the perception, feeling or memory to my self symbol schema.
     • My attention can only be on one thing at a time (see attention is single-threaded), this is the way that attention works. The primary reason for this is so that my brain and therefore my body can take coordinated action.
     • Hence my conscious perception via attention feels like a unity, a perception of a single thing, at a time.
     • Of course, attention can change between different things and between different senses, and between internal memories and external things, very quickly.
• These explanations agree with experimental results, and a number of theories arising from the results, of investigations into what are usually called neural correlates of consciousness, i.e. what activity is required in the brain for a conscious experience.
  • The common finding is that consciousness requires large and long-lasting networks, and also that, when we lose consciousness, either because of sleep or general anaesthetic, it is the large networks that are disabled⁵.
  • In particular, the loss of efferent connections in the cortex has been shown to be a possible cause of vegetative state⁶, and my proposals show how efferent connections are required for attention, feeling, and therefore consciousness.

Other theories of consciousness

• Many proposals and theories have been put forward over the years to try to explain consciousness. Some have elements in common with my proposals on this website, and so may provide some support or evidence; others are very different from my proposals and do not seem to contribute to an understand of consciousness at all. The following list is obviously not complete, but covers those that I feel are the most significant (for a recent review that includes a list of Theories of Consciousness and a useful glossary, see Seth and Bayne 2022⁷).
  • Higher-Order Theories of consciousness is an umbrella term for a number of related theories that propose that consciousness arises when a higher-level mental state thinks about a lower-level one, and in particular when a higher-order mental representation of “the self” thinks about a lower-level mental state¹.
    • Like my proposals on this website, these theories suggest that there is a hierarchy of mental states, with the one representing “the self” being the highest level. My proposals say that consciousness of a particular object or concept arises when the self symbol schema “connects to” the symbol schema that represents that object or concept via the process of attention, where “connects to” means being mutually involved in a self-perpetuating oscillating loop of neurons that survives for many seconds.
    • The hierarchical process of attention is a well-understood physical process in the brain, but, although it is discussed in these theories, it does not seem to be acknowledged as a possible way in which higher-level states become linked to (“think about”) lower-level ones.
    • Although these theories happily talk about representations of “the self” and possibly other lower-level things, the way these representations are created is not discussed, and the creation of a model of the world, or a model of “the self” is not an aspect of these theories.
    • The definition of a “mental state” is not clear; sometimes it is said to be a “representation”, but at other times it seems to be a more general brain “state”.
    • Evidence for or against these theories is very much dependent on assumptions about the usage of specific brain areas.
    • These theories do not explain how or why consciousness comes about when the particular circumstances arise of a higher-level mental state thinking about a lower-level one.
  • Global Workspace Theory (GWT), originally proposed by Bernard Baars, says that consciousness occurs when a piece of information is broadcast to a sufficiently large area of the brain. Stanislas Dehaene extended this to become the Dehaene-Changeux Model (DCM) or Global Neuronal Workspace (GNW). It has also been called the Neuronal Global Workspace theory.
    • The original theory did not specify how or when certain information reaches the Global Workspace, or how or why consciousness then occurs.
    • The additions of the Global Neuronal Workspace theory specify that the selection process is attention.
    • Research has shown that information is retained for much longer when it reaches the Global Workspace.
    • My proposal is that information (in the form of signals from internal or external senses, or from inside the brain) makes it way up a hierarchy of afferent processing steps, which means it is also subjected to the filtering process called attention, mediated by biased competition from lateral inhibition.
    • During this processing, the data potentially becomes more compressed, generalised, abstracted or invariant at each level.
    • If this information flow gets as far as connecting with the self symbol schema, then the thing being processed, represented by one or more symbol schemas, becomes the subject of conscious attention, so is conscious.
  • Integrated Information Theory, first proposed by Giulio Tononi, defines a measurement of information that is required for something to become conscious.
    • The complicated measurement has had some success in correlating with expected levels of consciousness.
    • But it also apparently provides some results that are clearly nonsense.
    • The theory does not say how or why consciousness occurs when sufficient information is present.
  • Antonio Damasio’s theory of consciousness defines three hierarchical layers of consciousness, the Protoself, Core Consciousness and Extended Consciousness.
    • This division and their definitions may be helpful in understanding consciousness, but does not help in any substantial way to explain how or why it arises.
  • Attention Schema Theory (AST) by Michael Graziano is very similar to a key part of my proposals. It says that consciousness is a model of attention.²
    • My proposal is that attention is just one of the many brain processes that are modelled by the brain and become part of the self symbol schema.
    • For more on this and further references, see cognoception, my name for the processing of data from within the brain.
  • Data compression (sometimes called “Compressionism”) is proposed by some to create intelligence and consciousness^{3, 4}. This theory says that “the awareness of a system is something that can be quantified in terms of the data compression it carries out, and that conscious systems are those whose data compression is so sophisticated as to be feasibly irreversible, thus forcing observers to adopt the intentional stance to make predictions about behaviour.”
  • Quantum mind covers proposals by various people, most notably Roger Penrose, that there is a link between collapsing a quantum superposition and consciousness, and that consciousness could be created by quantum processes within neurons. Penrose’s theory was later developed into Orchestrated objective reduction (Orch OR).
    • There certainly are quantum processes going on in the brain if you care to examine closely enough.
    • As far as I know, no-one has made any concrete proposal as to how quantum effects could possibly create what we feel as consciousness.
    • The proposals, and others like it such as Holonomic brain theory, have been criticised for mixing two very distant levels of description.
  • Electromagnetic theories of consciousness also do not explain how or why consciousness is created and also confuse very different levels of description.
• Over the years there have probably been more varied and confused theories about consciousness than any other life science subject. The difficulty is of course that we all think we know what it feels like, but it is our own brain that is doing both the thinking and the feeling.

Final points

• Consciousness is affected by my state of alertness, sometimes also called arousal.
  • Although it is not easy for me to recognise it at the time, my level of consciousness varies somewhat depending on how tired I am.
  • It varies a lot more if I am under the influence of any neuromodulating drug (e.g. alcohol).
  • It is absent entirely if I am in deep sleep, in a coma, or under the influence of anaesthetic⁵.
  • Since I can only be aware of a schema of my own consciousness, I cannot innately be aware of the detail of how my consciousness works, the different elements of it, or what level of consciousness I have at any one time.
• Some people have claimed that dreaming sleep (REM) is a form of consciousness, but I am convinced that it is only a very low level by my definitions above.
  • There can often be some level of self-awareness in dreams, including some (often confused) access to memories and some level of emotion, but there is no real attention and very poor reinstatement.
  • Memories are not laid down in the same way when dreaming. I can sometimes remember some dreams immediately after I wake up, but the memory is not retained, a few hours later it is often gone.
  • The level of self-awareness in daydreaming and dreams is different from fully-awake self-awareness. In daydreams and dreams, I have an awareness of me and some awareness of who I am, but none of the here-and-now; when fully awake and aware, I have a much more immediate sense of me and who I am and of being in the present.

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References For information on references, see structure of this website - references

1. ^ Empirical support for higher-order theories of consciousness - Lau and Rosenthal 2011
   doi: 10.1016/j.tics.2011.05.009 downloadable here or see GoogleScholar.
   First paragraph: “Higher-order theories of consciousness argue that conscious awareness crucially depends on higher-order mental representations that represent oneself as being in particular mental states.”
   Second paragraph: “Conscious awareness crucially depends on higher-order representations, specifically mental states that represent oneself as being in the relevant first-order mental states.”
2. ^ Consciousness Engineered - Graziano 2016
   Journal of Consciousness Studies, Volume 23, Numbers 11-12, 2016, pp. 98-115, downloadable here or see GoogleScholar.
   This interesting paper details how some substantial part of self-awareness could arise through what is called an “attention schema”, with parallels drawn to the “body schema”.
3. ^ Compressionism: A Theory of Mind Based on Data Compression - Maguire, Mulhall, Maguire and Taylor 2015
   downloadable here or see GoogleScholar.
   This very interesting paper contains a discussion on how compression can lead to intelligence, but goes a lot further in its claims (see self-awareness).
   The following is a quote from an old draft page based on this paper on wikivisually which no longer exists: “Compressionism is the idea of representing intelligence and/or consciousness in terms of data compression. ... Compressionism proposes that the awareness of a system is something that can be quantified in terms of the data compression it carries out: conscious systems are those who [sic] data compression is so sophisticated as to be feasibly irreversible, thus forcing observers to adopt the intentional stance to make predictions about behavior.”
4. ^ Understanding Consciousness as Data Compression - Maguire, Moser and Maguire 2016
   Journal of Cognitive Science 2016 Volume 17, Issue 1, Pages 63-94 downloadable here or see GoogleScholar.
   Despite the misleading title of this paper and some sections that I think are best ignored, section 3 (pages 68-72) has a useful discussion on compression and how it can lead to successful prediction and therefore create intelligence, and section 5.1 (page 85) touches on “self-compression”.
5. ^ ^ General Anesthesia and Human Brain Connectivity Hudetz - 2012
   doi: 10.1089/brain.2012.0107 downloadable here or see GoogleScholar.
   This article outlines the state of understanding of the action of general anaesthetics, which is, in summary, that we do not know for sure what causes consciousness to be lost when anaesthetics are administered, but the loss of large-scale networks is one possibility.
   Middle of abstract on page 291: “At an anesthetic depth characterized by the subjects’ unresponsiveness, a partial, but not complete, reduction in connectivity is generally observed.”
   End of introduction, page 292: “...three aspects of brain activity during anesthesia have been studied with neuroimaging: (1) the degree of baseline activity, as reflected by regional cerebral metabolic rate (CMR) and regional cerebral blood flow (CBF), (2) the responsiveness of neuronal networks to sensory input or task, and (3) the functional connectivity of large-scale networks of the brain. Currently, functional connectivity is in the forefront of interest.”
   Beginning of conclusions on page 299: “The modulation of functional connectivity by general anesthetic agents is an active area of investigation. To date, no consensus has emerged with respect to the common neural mechanism by which anesthetics modulate the state of consciousness. The significance of functional brain connectivity changes during general anesthesia for the loss and return of consciousness remain to be confirmed.”
6. ^ Preserved feedforward but impaired top-down processes in the vegetative state - Boly, Garrido, Gosseries, Bruno, Boveroux, Schnakers, Massimini, Litvak, Laureys and Friston 2011
   doi: 10.1126/science.1202043 downloadable here or see GoogleScholar.
   End of abstract, page 858: “We measured effective connectivity during a mismatch negativity paradigm and found that the only significant difference between patients in a vegetative state and controls was an impairment of backward connectivity from frontal to temporal cortices. This result emphasizes the importance of top-down projections in recurrent processing that involve high-order associative cortices for conscious perception.”
7. ^ Theories of consciousness - Seth and Bayne 2022
   doi: 10.1038/s41583-022-00587-4 downloadable here or see GoogleScholar.
   Start of abstract: “Recent years have seen a blossoming of theories about the biological and physical basis of consciousness. Good theories guide empirical research, allowing us to interpret data, develop new experimental techniques and expand our capacity to manipulate the phenomenon of interest. Indeed, it is only when couched in terms of a theory that empirical discoveries can ultimately deliver a satisfying understanding of a phenomenon. However, in the case of consciousness, it is unclear how current theories relate to each other, or whether they can be empirically distinguished.”

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