Scientific Understanding of Consciousness
Consciousness as an Emergent Property of Thalamocortical Activity

A Little More Discussion on ‘What Is Consciousness’

How do the brains in our heads mediate our perceptions of the world, our emotions, our reverie, our memories, our beliefs, our dreaming at night, etc? What biology of our brains, derived from (1) our parents and other ancestors’ genes and (2) our prenatal and postnatal development in the environment throughout adulthood, mediates the unique individuality by which we experience the world.

(It’s best to start at my title page — Scientific Understanding of Consciousness)


Knowledgeable and authoritative scientists in the last fifteen years or so have begun to apply the methods of science to the neurobiology of the brain. The results so far are beginning to be encouraging. Although the hypotheses, experimental observations and interpretations are somewhat varied among the different researchers, some very interesting insights have been published. In the usual progression of science, these working hypotheses will be modified, expanded and extended as further experimental observations and insights become available. During the course of a number of future decades, the scientific understanding of the working of the brain, mind and consciousness will gradually evolve into a much more mature science.

Neural science, the modern science of the brain, emerged in the mid-1970s. (Kandel; Principles of Neural Science, 313)

The explanation of consciousness is one of the major unsolved problems of modern science. (Crick & Koch; Consciousness and Neuroscience, 50)


Neuroscience is among the fastest-growing disciplines of biology and has shown extraordinary recent productivity. Indeed, we have probably learned more about the brain in the past 20 years than in all of recorded history.” (Alan I. Leshner, chief executive officer of the American Association for the Advancement of Science and executive publisher of Science, 18 May 2007, p. 953)



Illnesses such as schizophrenia, autism, and mood disorders are likely the result of disruptions of neural circuits, the functional ensembles of brain cells that mediate thought, feelings, and behavior. Given the complexity of neural circuits, thousands of genes are involved in regulating neural development and function. Disturbances in one or several of these genes can lead to broad and complex neuropsychiatric phenotypes.

Now is the time to initiate an effort that relies on the combined power of (1) large-scale sequencing with systematic computational analysis of genomes and (2) circuit analysis of the structure, function, and dysregulation of relevant neural circuits. These efforts would begin by focusing on autism, schizophrenia, and bipolar disease, but would eventually include the study of other severe psychiatric disorders, especially major depression. (Future of Psychiatric Research - Genomes and Neural Circuits)

(end of paraphrase)


In these web pages I have attempted to present my own interpretation of consciousness based on a consistent set of the most valid of these authoritative scientists’ insights. I believe my interpretation and working hypothesis will, in general, still be valid a good many decades from now.

Avoid precise definition

It is better to avoid a precise definition of consciousness. Until the problem is understood much better, a formal definition is likely to be  misleading or overly restrictive. (Crick; Astonishing Hypothesis, 20)

Until the problem is better understood, a formal definition of consciousness is likely to be either misleading or overly restrictive, or both. (Koch; Quest for Consciousness, 12, 20)

John Searle gives a common sense definition of consciousness as referring to “those states of sentience and awareness that typically begin when we awake from a dreamless sleep and continue until we go to sleep again, or fall into a coma or die or otherwise become unconscious.” (Searle; Mystery of Consciousness, 5)

We should not nitpick words and definitions in current descriptions relating to consciousness. If we get the gist of an idea being alluded to, that should be sufficient at the present time.

Consciousness is inextricably bound to the biological mechanism of the brain. When the biological mechanism ceases to function, as in death, consciousness ceases to exist.


Experts provide their insight on consciousness

Consciousness is the most baffling problem in the science of the mind.  There is nothing that we know more intimately than conscious experience, yet there is nothing that is harder to explain. (Chalmers; Problem of Consciousness, 5)

The really hard problem of consciousness is the problem of experience. (Chalmers; Problem of Consciousness, 6)

Consciousness is comprised of a dynamic interaction of multiple brain regions. (Edelman; Wider than the Sky, 31)

Consciousness - "remembered present" - reflecting the fact that all past experience is engaged in forming an integrated awareness of this single moment. Primary consciousness is the state of being mentally aware of things in the world, of having mental images in the present. It is possessed by animals lacking semantic or linguistic capabilities. Higher-order consciousness involves the ability to be conscious of being conscious. Recreate past episodes and form future intentions. (Edelman; Wider than the Sky, 8-9)

Self-reflective awareness is the essence of what we imply by the term consciousness. (Hobson; Dreaming as Delirium, 141)

Consciousness is a momentary creation of neural patterns, which describes a relation between the organism, on the one hand, and an object or event, on the other. (Damasio & Meyer; Consciousness Overview, 6)

Consciousness as we commonly think of it, from the basic levels to the most complex, is the unified mental pattern that brings together the object and the self. Core consciousness provides an organism a sense of self about one moment. The scope of core consciousness is the here and now. Extended consciousness is also present in some nonhumans at simple levels; it only attains its highest levels in humans where it is also enhanced by language. (Damasio; Feeling of What Happens, 11, 16)

The term feeling should be reserved for the private, mental experience of an emotion, while the term emotion should be used to designate the collection of responses, many of which are publicly observable. (Damasio; Feeling of What Happens, 42)

The number of conscious experiences that can be derived from combinations of multimodal sensory elements is virtually infinite, and conscious organisms benefit from the ability to distinguish between these different states.  The ability to make this discrimination is the essential (functional) role of consciousness. (Johnston; Why We Feel, 126)

Primary components of consciousness are those experienced by all mammals, including human infants: sensation, perception, attention, emotion, instinct, movement. Secondary components of consciousness are those experienced only by adult humans: memory, thought, language, intention, orientation, volition. Consciousness is graded across species as they develop over evolutionary time (phylogenesis). Consciousness is graded within species over each individual's lifetime (ontogenesis). Consciousness is modulated in everyone over the course of each 24-hour day. (Hobson; Consciousness, 16-17)

When does consciousness begin? We all spend a very significant amount of time in a very REM-like state before we were born. Embryologists can see eye movements in fetuses only twenty weeks old. (Hobson; Dreaming as Delirium, 141)

The stuff we are conscious of is the stuff working memory is working on. (LeDoux; Synaptic Self, 191)

There may exist primitive levels of consciousness, especially involving the passive awareness of events as opposed to the active use of on-line information to guide decision-making and behavior. These kinds of mental states may typify consciousness in organisms that have less or no prefrontal cortex. (LeDoux; Synaptic Self, 192)

Consciousness is a noncontinuous event determined by simultaneity of activity in the thalamocortical system. Secondary qualities of our senses such as colors, identified smells, tastes, and sounds are but inventions/constructs of an intrinsic CNS (central nervous system) semantic. (Llinás; I of the Vortex, 124, 128)

Dialogue between the thalamus and the cortex generates subjectivity in humans and in higher vertebrates. (Llinás; I of the Vortex, 131)

Consciousness includes perception, cognition and feelings. Cognition involves perception, memory, evaluating, planning. Feelings include affects and emotions. (Koch; Quest for Consciousness, 238)

Minds are functional states of our brains; mind is not a spirit; it is not an independent entity. (Hobson; Dreaming, 64)

The ultimate question: How do subjective sensations -- different states of consciousness -- occur as a result of the shifting neuronal network activity within the physical brain? No single chemical or process in the brain is solely responsible for consciousness. No central brain region for consciousness. (Greenfield; Private Life of Brain, 163)

Consciousness matters; it allows us to do all kinds of things that would be impossible without it. (Zeman; Consciousness, 287)

Consciousness depends upon dialog between diverse regions of the brain, associated with independent psychological functions such as perception, emotion, memory, and action. (Zeman; Consciousness, 291)

Synchronized activity across brain regions at around 40 Hz; a signature of wakefulness, provides a mechanism by which the contents of consciousness can be bound into a unified whole. (Zeman; Consciousness, 301)

40 Hz oscillation; signature of perceptual awareness and a candidate for the mechanism of binding, may prove to be the most convincing physiological correlate of consciousness. (Zeman; Consciousness, 324)

Consciousness helps to select appropriate actions in an unpredictable world, actions we choose from an ample repertoire on the basis of fine perceptual distinctions. (Zeman; Consciousness, 296)

Edelman’s ‘Dynamic Core’ - a shifting coalition of 'strongly interacting elements'. At any given time, the dynamic core is responsible for 'primary consciousness', our perceptual experience. (Zeman; Consciousness, 288)

Consciousness is a dynamic organization existing within many different areas of the brain. (Johnston; Why We Feel, 122)

Consciousness as an Emergent property

Consciousness arises as an emergent property of the biological neural network in the brain. This thesis has been stated in a number of ways by science experts:

"You" are the behavior of a vast assembly of nerve cells and their associated molecules.  (Crick; Astonishing Hypothesis, 3)

Scientific meaning of emergent -  The whole may not be the simple sum of the separate parts. The whole can be understood from (1)  behavior of the parts plus (2) knowledge of how all the parts interact. (Crick; Astonishing Hypothesis, 11)

Consciousness emerges from neuronal features of the brain. A system has emergent properties if these are not possessed by its parts. There are no mystical or new-age overtones to this. (Koch; Quest for Consciousness, 10)

Physical basis of consciousness is an emergent property of specific interactions among neurons and their elements. Although consciousness is fully compatible with the laws of physics, it is not feasible to predict or understand consciousness from these. (Koch; Quest for Consciousness, 11)

Consciousness does not constitute a single generalized process can but is an emergent property that arises out of hundreds if not thousands of specialized systems (modules). (Gazzaniga; Left Hemisphere/Right Hemisphere, 262)

Consciousness is an emergent property arising from the self-organization of concurrently active but spatially distributed regions of the brain; there is no central organizer and no unique location where it comes into existence. (Johnston; Why We Feel, 124)

Conscious experiences are evolved emergent properties of biological brains. (Johnston; Why We Feel, 58)

Human conscious experiences are emergent properties that arise from the complex arrangements and interconnections between nerve cells. (Johnston; Why We Feel, 59)

The liquidity of water is an emergent property. Nothing in the equations of atomic physics even hints at such a property. (Waldrop; Complexity, 82)

Life is an emergent property, the product of DNA molecules and protein molecules and myriad other kinds of molecules, all obeying the laws of chemistry. (Waldrop; Complexity, 82)

The mind is an emergent property, the product of billions of neurons obeying the biological laws of the living cell. (Waldrop; Complexity, 82)



It's in this no-man's land between quantum and classical physics that a wide array of “emergent” phenomena reveal themselves. For example, superconductivity, in which electrons flow without resistance, arises only in large collections of atoms. Properties such as magnetism, rigidity, and melting are other collective behaviors that cannot be understood at the atomic level, says Robert Laughlin, a physicist at Stanford University in Palo Alto, California. Even life itself is considered an emergent phenomenon. “I know molecules and reactions are not alive. But I also know that collections of reacting molecules are alive. How does that happen? We have no clue,” says George Whitesides, a chemist at Harvard University. (Science, 9 March 2012, p.1167)

(end of paraphrase)


Do Non-Human Animals have consciousness?

It is plausible that some species of animals -- mammals, in particular -- possess some, but not necessarily all, of the features of consciousness. It would be contrary to evolutionary continuity to believe that consciousness is unique to humans. (Koch; Quest for Consciousness, 12, 19)

Humans and higher animals are obviously conscious, but we do not know how far down the phylogenetic scale consciousness extends.  (Searle; Mystery of Consciousness, 5)

Not profitable to argue about whether lower animals (octopus) are conscious. It is probable that consciousness correlates to some extent with complexity of any nervous system. (Crick; Astonishing Hypothesis, 23)

Computers can't have consciousness

Can computers be programmed to have the consciousness? The answer is NO! Consciousness depends on affective experience (i.e. the experience of one's own emotional patterns). True affects and their near infinite variations can only arise from living biological systems and their developmental processes. (Greenspan; First Idea, 292)

Computer cannot be conscious. (Zeman; Consciousness, 329)

Computers can simulate aspects of human thought, but we do not expect simulations to possess all of the properties of the processes they simulate. (Zeman; Consciousness, 333)

Avoid distraction by some traditional theories

Much has been written in the past on the subject of consciousness; most of it, in fact nearly all of it, is inconsistent with a scientific understanding of the neurobiology of consciousness. Especially confusing are many of the writings of philosophers. (Crick; Astonishing Hypothesis, 258)

It is important not to be side tracked by these distractions: Dualism; Materialism; etc.  (Searle; Mystery of Consciousness, 194ff)

Edelman's pithy characterization of philosophy as "a graveyard of Isms." de Duve, Vital Dust, 249)

Consciousness – Distinctions in Kinds and Levels

Demarcation between human-type consciousness and core consciousness. Only humans have Human-type consciousness, although some higher non-human primates may have some characteristics of human-type consciousness. Core consciousness is generally a characteristic of mammals, although reptiles may have some of the characteristics.

Distinction between Human-type consciousness and Core consciousness

Chimps can have some characteristics of human-type consciousness.

Distinction between Core consciousness and Non-consciousness animals

Core consciousness is generally a characteristic of mammals. Reptiles (snakes, lizards) may have some characteristics of core consciousness.

Levels of consciousness

Human-type consciousness built upon core consciousness can be viewed as ‘normal’ everyday conscious experience. The state of dreaming can be considered one state of consciousness. Abnormal states such as concussion, coma, vegetative state, etc. may have equivocal states of consciousness.

For most of us, our ‘normal’ everyday conscious experience involves our long-term declarative memory. However, this long-term memory is not necessary for consciousness, because we all probably agree that human infants have consciousness although they have not developed long-term memories.

Normal ‘everyday’ consciousness vs. minimal consciousness

Consciousness state can vary from highly alert, to relaxed reverie, sleeping, anesthesia, coma, vegetative state.

At today’s state of scientific knowledge, the minimal brain functionality required for consciousness is unknown.

My understanding is that functionality of portions of working memory, thalamocortical loops, and the limbic system would be required to comprise to a minimal dynamic core. Many other regions and functions would necessarily provide a supporting role but would not be a part of the dynamic core directly.

What is known is that the dynamic core of neural activity is the biological basis of consciousness. Consciousness is an emergent property of the dynamic core.

Minimal consciousness -- minimal brain functionality required

Human infants at some stage of development have core consciousness, although they do not have long term memory. Abnormal states resulting from concussion, anesthesia, coma, vegetative state, etc. may have transient states of partial or minimal consciousness.

We do not know the minimal conditions for consciousness. (Zeman; Consciousness, 285)

Damasio provides a brief description of coma and vegetative state. (Damasio; Feeling of What Happens, 236)

Chalmers’s "hard problem" and Flanigan’s Dissolution

Consciousness is the most baffling problem in the science of the mind.  There is nothing that we know more intimately than conscious experience, yet there is nothing that is harder to explain. (Chalmers; Problem of Consciousness, 5)

What Chalmers calls the "hard problem" of consciousness    is the problem of explaining how subjectivity can arise from complexly organized material stuff. (Flanigan; Dissolution of hard problem, 148)

It is amazing that consciousness can emerge from brain processesExplaining the mechanisms that give rise to the different types of waking consciousness, NREM, and REM mentation, is all  there is to solving the "hard problem." (Flanigan; Dissolution of hard problem, 148)



    Link to — Synopsis of Consciousness

    Link to — Introduction to Consciousness

    Link to — Consciousness Subject Outline

    Further discussion -- Covington Theory of Consciousness