Human consciousness, the human soul, the human mind, human subjective feelings have been a matter of concern, not only for philosophers and theologians, but recently also for neuroscientists, physicists and others. Our approach to understanding this problem is based on the fact that even the simplest brain functions depend on the activity of an enormous number of neurons, on their synaptic connections and on associated ionic and electrical events. The synaptic delay in each of those synapses is at least 0.5 ms and therefore the parallel and serial interactions between millions of neurons would take a very long time, too long for the individual.s adequate interaction with the environment. Therefore, there must be some other mechanism governing the interactions of large numbers of neurons, located even in remote parts of the brain. However, the neuronal function - with a spreading of depolarizations, hyperpolarizations and repolarizations, graded and ungraded electrical potentials, ionic movements and small local electrical fields - creates a unique and very complicated system of the movements of subatomic particles. When moving from one position to another, each electron fills a large space and its precise position cannot be exactly determined. Thus brain function depends on the movements of an enormous number of electrons which influence each other at the subatomic level, even though their position cannot be determined. Therefore, beside relatively slow "classical" electrochemical interactions, rapid quantum interactions originating in functioning cell membranes may participate in many, perhaps in all, brain functions. Together, all the moving electrons produce a non-local system which we call the Real Human Soul, RHS, which is created by the functioning neurons and, at the same time, can also influence other neurons. Thus, it creates a connection between all functioning parts of the brain. The brain then functions as a unified system in which everything is interconnected and is able to interact. Viewed thus, the brain functions as a quantum computer.
This system, the RHS, is not identical with consciousness. Only under certain conditions does some area of the brain create subjective consciousness, which may be one of the products of the RHS. Subjective consciousness is probably based on simple particle communication, their .proto-consciousness., but is much more complex, due to the neuronal analysis of sensory input and other cognitive functions of the CNS.
There are several definitions of consciousness, which usually depend on the philosophical views of their authors. Let us use a simple definition of consciousness, as found on the Internet (http://www.selfknowledge.com/19677 .htm): .The state of being conscious; knowledge of one.s own existence, sensations, mental operations, acts, etc. .Consciousness is thus, on the one hand, the recognition of the mind or .ego. of its acts and affections; - in other words, the self-affirmation that certain modifications are mine.. Sir W. Hamilton..
Describing the mechanisms which cause certain events in the brain to be subjectively perceived is the .hard. problem of neuroscience. Consciousness cannot be reduced to neuronal firing and neuronal interactions. On one hand, there are brain activities that can be objectively observed, recorded and measured by an external investigator. On the other hand, there exists our private, subjective perception of some of these events. Consciousness is our primary reality; through it, we perceive ourselves and our environment; we plan and accomplish our actions, evaluate them, think about them, record them. Some believe that consciousness is an emergent property of brain activity, others assume that there is a duality of matter and spirit, and that there exists an immaterial principle, a homunculus, controlling brain functions. But there might be some other possibilities as well.
The human brain is composed of billions of neurons and glia cells. There is an extracellular space between them, filled with fluid. This space is rather minimal, comprising about 5% of brain volume. The neurons communicate one with another through at least nine mechanisms:
All these are local phenomena belonging in the area of classical physics and its ramifications. The result of neuronal activation is an action potential generated by movements of electrons and ions, e.g. of potassium, calcium and sodium. A neuron producing an action potential usually requires at least ten synaptic inputs from other neurons to reach its firing level. Therefore, the function of the central nervous system depends on many serial and parallel interactions of masses of individual neurons. Each neuron is connected to hundreds and thousands of other neurons. In the brain, we may observe convergence and divergence, feedbacks and circulating nerve impulses. The reverberating neuronal circuits may be rather long, lasting up to one second (Reinis, 1997). All these events slow down the functioning of neuronal networks containing millions of neurons, so such sequences of neuronal firing cannot accomplish the function of more complex neuronal systems that are expected to respond in a real, sufficiently short time.
Despite these imperfections, the human brain is a uniquely complex system of electrochemical activities unlike anything in the known universe.
As a synaptic transmission takes at least 0.5 ms, transmission across thousands of synapses may take hundreds or thousands of milliseconds. The transmission of nerve impulses along an axon is also relatively slow, between 0.5 m/sec and 120 m/sec. As an example, more than fifty percent of nerve fibers in the corpus callosum are unmyelinated slow fibers with a transmission speed of 0.5 m/sec.
For this reason, we must search for another, more rapid mechanism of neuronal interactions to explain the speed of some fast reactions in the nervous system. Synaptic transmission and axonal transfer of nerve impulses are too slow to organize coordinated activity in large areas of the central nervous system. Numerous observations confirm this view.
For example, the analysis of visual input is rather complicated and time-demanding. The visual pathway begins in the retina, where the first analysis of the visual image is accomplished. Nerve impulses pass through approximately two million parallel nerve fibers for the most part into the lateral geniculate body and then into the primary visual cortex V1 (area 17). This transmission is a speedy one, taking just a few milliseconds. However, a considerable portion of the cerebral cortex, millions of synapses, are involved in the further analysis of the visual image. The shape, color, and position of the object and the speed of its movement are evaluated separately and finally, these attributes of the image are combined and integrated into the mental image of the observed object. The appearance of the observed object is compared with memory traces, emotions and past experience. The object.s meaning is recognized in the inferotemporal cortex. This whole procedure could not be handled without rapid coordination far exceeding the speed of multiple synaptic transmissions. Otherwise, the time for this analysis would make the visual input useless. Let us imagine an ice hockey or a baseball player who, in a fraction of a second, realizes the presence of a puck or a baseball, analyzes its position, its speed and the direction it is moving, and responds to it and to the presence of other players by a complex body movement. That would be impossible without some acceleration of the interneuronal connections. With accumulated synaptic delays, there would be no interesting game to watch.
In the auditory system, there is a number of examples as well. Libermann in 1970 wrote that the understanding of human speech and its formation is simply not possible, because neuronal mechanisms are too slow for this process. The auditory pathway passes from the inner ear through the fibers of the spiral ganglion into the nucleus acousticus in the medulla, into the colliculus inferior, into the medial geniculate body, into the primary and secondary auditory cortices and finally into the higher analytical cortical centers. At each of these levels, the incoming sound is analyzed again and again by systems of neuronal interactions, neuronal loops and feedbacks. The auditory brain stem potentials are still very fast, below ten milliseconds. Ultimately, the auditory input reaches the Wernicke area of the cerebral cortex which is scanned for memories of word sounds and for the meaning of the words, where each letter sound and each syllable is detected and a definite meaning attached to it. The limbic system provides emotional content to the perceived speech, and a response is determined in the context of stored memories and ideas. This response is then transferred to Broca.s area of speech, to the several other cortical motor centers, to the respiratory centers and to the muscles of the mouth, pharynx and larynx. All this is a very complex process which could not be handled without the speedy communication and correlation of various brain functions. Lacking extremely rapid communication between neurons, this process could not be accomplished in real time.
There are some other functions of the auditory system which cannot be explained by straightforward synaptic transmission. The auditory system is able to determine the direction from which a sound is coming by comparing the arrival of the sound into both ears. But, if we calculate the distance between the ears and the speed of sound, then it is obvious that one ear gets the sound only microseconds earlier than the other. Klumpp and Eady (1956) showed that at the frequency of 1 kHz, the time difference which gives a reasonable impression of the direction of the sound source is eleven microseconds. Even with the use of place and volley principles, it is impossible to explain how this difference is distinguished when the known synaptic delay is at least 500 microseconds. The human ear is also able to recognize frequencies to 16 to 20 kHz. That corresponds to a wavelength of 50 microseconds. The volley principle plays a certain role here again, and we were able to document it (Reinis, 1997), but still, the synaptic delay precludes a fine arrangement of nerve impulses. There are animal species which hear frequencies of up to 120 kHz and here, the explanation that each wave corresponds to one neuronal spike does not make sense.
This paradox is even more apparent in some species of bats, whose analysis of sound requires equally short time intervals. Searching for insects flying in the dark by echolocation, these bats can discriminate intervals in the range of microseconds and even less. They are able to distinguish the size of their prey which might be only 3 mm. This corresponds to a time interval of about one microsecond (Saillant et al., 1993). A specialized area of the cerebral cortex, the Doppler Shifted Constant Frequency Area (DSCF), analyzes small deviations in the frequency of originally emitted sound. Once more, this analysis is too quick to be easily explained by synaptic transmission.
These are some specific examples of a general rule stating that under normal conditions, there is only one stream of consciousness despite the involvement of a number of parallel neuronal systems. Subjectively, we receive many sensory inputs at once: visual, auditory, tactile, thermic, olfactory. All these inputs are analyzed at different time intervals and in different locations in the brain and yet they interact and we perceive them as simultaneous events. These systems communicate one with another, although they are located in many areas of the brain, primarily in the neocortex and also in the subcortical areas, and this communication must be very rapid, despite their relative distances one from another. The state of consciousness is accompanied by waves of electrical activity with a frequency of about 40 cycles per second which travel from the occipital areas forward (Pari and Llinas, 1995). Such waves involve large numbers of neurons and even larger numbers of neuronal connections. They must be organized in a meaningful way, and undoubtedly comprise a huge number of serial and parallel transmissions, feedbacks and complicated circuits, containing tens and hundreds of millions of neurons.
Some events in the brain have been observed that seem to shift the times and succession of certain events. Thus, Kornhuber and his group (Deecke et al., 1970) found that voluntary flexing of a finger is preceded by a cortical readiness potential in the cerebral cortex. This readiness potential comes one or two seconds before the muscle contraction. This time interval is obviously not sufficient for the control of fast and efficient movement. If each of our muscle contractions were preceded by such a long interval of movement preparation, no complex movements would be possible in real time.
Benjamin Libet.s experiments followed Kornhuber.s studies. They may also be considered evidence of time disproportions in the CNS (Libet 1978, Libet et al., 1979, Libet et al., 1983). In one typical experiment, Libet observed a delay in a cortical readiness potential, indicating the time of decision to make a movement. This time was longer than the time of onset of the actual accomplished movement. Subjects were told to flex their wrist at any time they chose, but to record the point at which they decided to do so by noticing the position of a dot on a clock face. Libet was able to record readiness potentials which occurred in the supplementary motor area. He showed that they occurred about 550 ms after the stimulus, while the movement itself occurred earlier, within 200 ms. Thus, there was a time difference of about 350 ms between the act itself, which occurred first, and the conscious intention to do it, which occurred later. In another study, he showed that if subjects have to record the position of a moving dot when they are given a skin stimulus, they actually recorded the sensation before it had actually happened by tens of milliseconds. Discussions concerning these papers imply that consciousness somehow manipulates the time base of the brain functions (e.g. Dennett and Kinsbourne, 1992). This antedating cannot be explained by any known neural mechanism. These experiments might be explained by a reversal of time by the CNS, but that idea is somewhat absurd.
Another similar case is the Color Phi phenomenon. The Phi phenomenon means that if two points in the visual field are illuminated successively within a time interval of less than 100 ms, there is an impression of movement. Television or motion pictures serve as an example. When these two points have a different color, red and green for instance, then the color changes in the middle between two points, that is, before the second point is shown (Kolers and von Gr|nau, 1976). This observation is present even during the first exposure, which means that the color change is predicted, and not a matter of learning. Van der Waals and Roelofs (1931) proposed that some sensory activities involve a backward projection of time.
There may be other examples. .Rabbit jumps. described by Geldard and Sherrick (1972) and the theory of equipotentiality of the cerebral cortex by Lashley may also eventually be considered an indication of fast non-synaptic connectivity in the brain. According to Lashley, memories are widely distributed across the brain. Therefore, they must communicate one with all the others very quickly. Lashley.s theory of equipotentiality is not widely accepted any more and therefore, we mention it here only as a possibility.
In the literature on quantum mechanics, we may find a number of interesting, but somewhat differing, views in this respect. Werner Heisenberg wrote in 1971:
.The same organizing forces which gave a form to nature in all its forms are also responsible for the structure of our mind..
Erwin Schroedinger went even further (1967):
"It is very difficult for us to take stock of the fact that the localization of the personality, of the conscious mind, inside the body is only symbolic, just an aid for practical use."
Schroedinger is probably not correct in his belief that consciousness is located outside the brain, somewhere in the universe. It is, we assume, the human (and perhaps some other as well) brain that produces it, and the contents of our conscious activities, thoughts, memories and intentions depend on sensory input and a large number of coordinated neuronal interactions. Consciousness cannot be reduced to neuronal activity, the functions of neurotransmitters and neuronal spikes. It is, however, influenced by mutual neuronal interactions mediated by synaptic and non-synaptic interactions.
Besides those nine possible ways of interaction between individual neurons and neuronal groups listed earlier, one has to hypothesize that there exist some additional, faster types of interaction. The most obvious might be electromagnetic interactions, electrical currents passing through the brain tissue. This possibility is not very acceptable. The brain is an organ formed by large numbers of cell membranes with a high impedance and a small amount of extracellular fluid in between. Electrical potentials produced by neurons and also glia must pass through high-impedance cell membranes and hence cannot get too far. For instance, the electrical potentials recorded in an electroencephalogram originate in the most superficial layers of the cerebral cortex. Potentials from deeper structures can be recorded only after numerous repetitions of the sweeps and their averaging, as seen in the recording of auditory brainstem potentials. Also, when we record the unit activity extracellularly, it is difficult to extract a signal from the noise at a distance larger than 100 microns.
There must be something occurring in the brain that is faster than synaptic transmission. As the most likely possibility we must consider submicroscopic interactions at a quantum level. This problem is also associated with human consciousness. As stated by Stapp (2004, p. 250), the problem of consciousness cannot be solved without considering quantum mechanics. The question is, how to use it, what kind of dynamics is suitable for this task.
There are three advantages to this quantum approach: First, that the temporary connection of various systems might be sufficiently fast; second, that the connections may be quickly terminated; and third, that quantum interactions may also help to explain subjective consciousness.
Submicroscopic particles may penetrate seemingly solid matter. They may pass at a supraluminal speed and their movement may be subject to non-locality as described by David Bohm (1951). This process may also take place in the brain.
Each neuron is composed of the nerve cell body, perikaryon, with the attached axon with its branches, telodendria, and with the dendrites. Synapses at the end of telodendria connect them with dendrites, perikarya or axons of other neurons. Several synapses must usually be activated to achieve production of a nerve impulse in the axon hillock. When a nerve impulse reaches the nerve ending, calcium ions enter the synaptic knob and elicit the release of synaptic vesicles containing a neurotransmitter. The released neurotransmitter activates the postsynaptic membrane and elicits the formation of EPSPs and IPSPs. These electrical waves spread over the surface membrane of the neuron decrementally. When they reach the axon hillock, they may produce a nerve impulse which moves along the axon, using circulating currents stimulating the axon toward its end, the synaptic knob. Each neuron is therefore a sufficient source of moving electrons which, as quantum particles fill the space, may interact with other electrons. The neuronal role as a generator of particles changes each nanosecond. There are at least ten billion neurons in the brain, all of them producing scores of particles.
All electrical phenomena in the neuron must be considered, those taking place on the surface of the brain cells, in the cell membrane, but also inside, in microtubules and mitochondria, those involved in the conformation of protein molecules etc. All of them together represent a powerful source of subatomic particles contacting, on a quantum level, particles generated by other neurons.
We call this conglomerate the RHS, Real Human Soul. The reason for this name is that this is the highest-level controlling system of the brain, analogous to the immortal human soul. However, the existence of the immortal human soul cannot be proven at the moment. The RHS activity ends when the neurons end their functions. It is not a homunculus controlling brain function from the outside, it is the highest-level system produced by the brain function itself. It is real, not mystical. It is not identical with .conscious mental field., as Libet describes it, because some parts of it are probably unconscious.
But the RHS does perform certain functions which are attributed by Eccles, Libet and others to the immortal soul.
Libet claims that in one of his experiments he stimulated the human supplementary motor cortex first, for at least 500 ms - which means that this stimulation was subjectively perceived by the experimental subject - and only then electrically stimulated the peripheral nerve. Subjective perception of the electric shock however came first, and the perception of the cortical stimulation followed. That means that the flow of subjective perception was changed. He is talking about time reversal, or effect of the immortal soul. It is neither.
If we accept the existence of the RHS complex, then we may hypothesize that this complex is not conscious, but is able to organize neuronal activity according to certain rules, rearrange the sequence of perceived events, make a decision when brain activity becomes conscious so that perception of peripheral stimulation comes first, as it is supposed to come in normal life, and cortical stimulation later, as it is supposed to be. The entry into consciousness may be also postponed or advanced. The motor action, as shown in the example of car driving or sport activity, may come first, and conscious subjective perception later. Libet speaks about the modulation of conscious experience, and we believe that this is one function of the RHS. Conscious perception is not part of the RHS complex, conscious perception comes after a longer action of RHS. Libet estimates that it takes at least 500 ms to activate consciousness.
This explanation does not postulate time reversal, which is a weird notion we did not feel very comfortable with. Nor does it eliminate free will but rather situates it into the RHS.
From what we know, we may conclude that the RHS receives not only events taking place in the present, but also events in the recent past, compares them and achieves the continuity of perception. An example comes from Erwin Husserl (translation from 1991), who wrote that in the consciousness, the .present time, perception of precious moment., as they call it, lasts several seconds and gradually fades away. Therefore, we are able to perceive a melody as a whole, a spoken sentence as whole. The recent past is still present as a set of .virtual. electrons in the RHS, compared with the present and analyzed together.
The human brain is enormously complex. It is the most complex structure we know. The RHS is also enormously complex. It is formed by all moving electrons together. It unifies the actions of all neurons. It is, on the other hand, also able to select individual neurons and induce their firing. This firing causes a new change in the system, selecting new neurons, inducing their functional changes and using electrons produced to its own new change. All that is supplemented by a continuing input of all sensory activities which also brings about its change. Ideally, it would be possible to assemble Markov mapping of the groups of neurons.The RHS is a basic mechanism of brain function. It is, perhaps, a non-local phenomenon where all moving electrons interact. It forms a powerful, perpetually changing but more or less unified system. It is necessary to note that the brain is a warm and large physical object and the interactions of quantum particles arising from the electrophysiological activities in it are extremely short. This may be an advantage, since brain activity changes very quickly. We anticipate that such an enormous collection of quantum events does not have a homogeneous structure. There may be partitions specifying close connections. However, whatever happens in any part of this conglomerate is reflected in other parts of it. This choice may play a decisive role in the functioning of the RHS.
The movements of electrons are also elicited by molecular synthetic and catabolic actions. This complicates the situation tremendously, because they all produce quasi-particles of a quantum character, with similar characteristics. However, we assume that these metabolically created and utilized particles form some continuous noise which does not substantially influence the neural processes.
The target of the quasi-particles may be electrically stimulated ionic channels, which then increase the efficiency of synapses. These channels may be in the postsynaptic membranes and increase the amplitudes of EPSP by the passage of sodium and potassium ions through the membrane. Or, they may be in the presynaptic membranes, increase the activity of calcium channels and therefore increase a release of synaptic vesicles and thus, the amplitude of the postsynaptic potentials. A minute quantum action may be sufficient to trigger the whole process. Quantum processes regulating the transport through the biological membranes were observed in photosynthetic bacteria (Vos et al., 1993).
Non-synaptic transmission is probably also connected with the appearance of consciousness. It is known that in the brain areas involved in increased attention, the rate of neuronal firing increases (Wurtz et al., 1980). The amplitude of cortical evoked potentials also increases when influenced by conscious attention (Desmedt and Tomberg, 1995). This increased activation is accompanied by increased blood flow detectable by functional neuroimaging such as positron emission tomography, magnetic response imaging (Rees, Kreiman and Koch, 2002) or even by a simple measurement of temperature in the active area or of blood coming from that area.
It is difficult to believe that human consciousness appeared in evolution all of sudden, without any simpler precursors. Something similar but simple must exist in nature. The brain utilizes many known physical and chemical mechanisms. It also utilizes the mechanisms of the submicroscopic quantum world. Is there something simple in nature that could be used for the formation of human consciousness?
There might be. Particles communicate with one another and with the environment, e.g. in the presence or absence of the second slit in the two-slit experiment. The particles .know., .feel. and according to some theoreticians even .remember.. Of course, this description is metaphoric. The particles do not .know. anything in a human, psychological sense. They are not conscious as we humans understand it. Their interaction is a physical, not a psychological event. But this physical property may be the elementary function on which the human consciousness is based.
Is this then a very elementary kind of consciousness, some kind of proto-consciousness? Subatomic particles may also be influenced by human conscious events, as seen, e.g., in some modifications of the two-slit experiment. This is possible because they share something, they have something in common. It may be assumed that this proto-consciousness could be a simple building block of actual human consciousness.
Of course, individual human consciousness is much more complicated than the proto-consciousness connecting two electrons. Human consciousness contains and handles information. The contents of our subjective human consciousness are determined by the neuronal mechanisms of sensation, perception, association, memory etc. The state of consciousness itself may be related to the proto-consciousness of elementary particles, which may give objective brain events their subjectivity.
Conscious activities form only a small segment of brain function and of the RHS. Consciousness probably depends on the RHS. Its appearance probably depends on the mass of neurons involved and duration of the involvement ( Libet et al., 1983).
It is also possible that there are areas in the brain which are suitable for the production and perception of conscious experience (Baars 1995). The RHS involves all the movements of electrons in the brain, and therefore, the entire brain function. Under certain conditions.duration of the contact, power of the contact, anatomical arrangement.the RHS creates consciousness. This appearance may be only temporary and volatile. Real reasoning, most activities of the mind, are unconscious and the results may become a component of the consciousness.
There are therefore several characteristics of the RHS which may be deduced from known data:
This proposal of a non-synaptic quantum mechanical hypothesis of brain function elicits a number of questions that still remain open.
The first question is: What is the chemical reaction responding to a quantum event? It may be the isomerization of a relatively simple organic molecule, or some effect on the second messenger system within the sensitive neuron, an effect on electrically excitable ionic channels, an effect on the movement of synaptic vesicles to the surface membrane of the nerve endings. These and other possibilities may be elucidated experimentally by existing methods.
The second open question is: How is the specificity of the non-synaptic connections maintained? It is obvious that the electrons do not carry any complex information. We may assume that the triggering non-synaptic event only influences some sensitive neurons in the local network. This is also a problem which may be solved by existing electrophysiological methods, such as that of Reinis (1997).
Stapp, who came to similar conclusions, stated in this respect (2004, p. 252): .The laws of contemporary quantum theory, although highly restrictive, are not the whole story: There is still work to be done. Hypotheses must be formulated and tested..
However, since the brain function, to a certain degree, resembles a quantum computer, there might be a number of quantum functions utilized in both. There might be a quantum interference, superposition, entanglement, non-determinism, non-clonability, transfers of groups of electrons resembling teleportation, transfers of other ions, cavity quantum electrodynamics, arrangement of electrons and other particles according to the Pauli principle, qubits that can exist not only in a state corresponding to the logical state 0 or 1 as in a classical bit, but also in states corresponding to a blend or superposition of these classical states (Williams and Clearwater, 2000). A qubit can exist as a zero, a one, or simultaneously as both 0 and 1, with a numerical coefficient representing the probability for each state. Combined with massive quantum parallelism achieved through superposition, the neuronal systems may have an enormous computing power. Exploration of algorithms describing these activities is a matter of future, and parallel studies of quantum mechanisms and living neuronal systems might be very fruitful.
It seems to be obvious that a digital computer cannot perform all the functions of the brain (Penrose 1994). The quantum computer eventually can. The quantum computer may be eventually closer to the brain function that the digital computer.
We have to keep in mind that the analogy between the brain and a computer is very superficial. How to determine a qubit in the brain? How is it related to a functioning neuron? How to determine the difference between memory registers and processing units in the brain?
The warm and wet inner environment of the brain does not allow any long-time entanglement and superposition of two functional units. How is then the computational activity of the brain accomplished?
How is the brain protected against errors coming from its environment, both within the body and outside? How are the errors corrected? Is there any similarity in the quantum error correction proposed by researchers involved in quantum computer research and correction of errors in the brain? How is the classical neuronal function related to the quantum computation events, in particular in view of the fact that a quantum computer may be formed just by a single molecule (Chuang et al, 1995)
Perhaps, the answer to the question of computer-like functions of local neuronal systems is in the interaction of RHS with the brain structure which at the same time creates the RHS. That means that the interaction between classical and quantum mechanisms may give us some answers as well.
Another open question remains: What is the difference between the conscious and the unconscious processes in the brain? Studies by Merikle et al. (e.g., Visser and Merikle, 1999) indicate that the difference between them is not very sharp, the transitions between the two are rapid, temporary and dependent on emotions. It is, therefore, possible that the difference between the conscious and the unconscious is quantitative. The more synaptic and nonsynaptic events there are in a certain area of the brain, the higher the possibility that the event itself enters the consciousness. As an example, the visual pathway from the eye into the lateral geniculate body is unconscious, area V1 of the cortex may be conscious under certain circumstances, and events in areas V2 and higher are conscious. This probably depends on the number of acting elements. The human cerebral cortex represents about 75% of the brain mass, and most conscious events may take place within it. On the other hand, at a low level of firing and neuronal interactions, consciousness does not substantially exceed the level of protoconsciousness.