Qualia, conscious awareness, and conscious experiences are mental phenomena that have been puzzling human minds for a long time. They are difficult matters, and the hard problem of consciousness and the explanatory gap originated from these mental phenomena [1-7]. So, three chapters will be dedicated to analyzing them. The first one, this chapter, will clarify what they are characteristically, their definitions, and their types. The next two chapters will answer the problems of what they are physically, why they occur, how they occur, and other related questions, including the hard problem of consciousness and the explanatory gap.
3.1. Quale and qualia
When one looks at a house, the vision of the house appears in one’s mind, and one can be aware of the vision and experience it in one’s mind. When one listens to a song, the sound of the song appears in one’s mind, and one can be aware of the sound and experience it in one’s mind. When one smells a rose, the odor of the rose appears in one’s mind, and one can be aware of the odor and experience it in one’s mind [Figure 3.1]. Likewise, similar phenomena related to other kinds of sensory perception (taste, touch, pain, etc.) can appear in one’s mind, and one can be aware of them and experience them in one’s mind, too. Moreover, other mental phenomena that are not related to sensory perceptions, such as the thought, the happiness, and the recalled past memory, can appear in one’s mind, and one can be aware of them and experience them in one’s mind, as well.
Figure 3.1 Visual, auditory, and olfactory qualia
The way that the mind is aware of and experiences these phenomena has three important characteristics. The three important characteristics are as follows:
#1. The mind has the awareness of the phenomena’s existence, that is, their existence is registered into the information and the processing systems of the mind.
#2. The mind has the awareness and experiences of what the phenomena are like – what the vision of the house is like, what the sound of the song is like, what the odor of the rose is like, what the thinking of something is like, what the feeling of happiness is like, etc.
#3. The mind can share the information of the phenomena to its various parts that include the cognition part, the symbolizing part, and the storage part. Thus, it can think about, analyze, compare, and do other mental activities with the phenomena intentionally; it can directly represent them with symbols, such as with written signs, sounds, and gestures; and it can intentionally memorize and recall them, at least with some details and for some time.
In this theory, when the mind is aware of and experiences a mental phenomenon with these three important characteristics, the mind is said to be consciously aware of and consciously experience the mental phenomenon, and the mental phenomenon is concisely said to be consciously experienceable.
This is in contrast to other mental phenomena that are not consciously experienceable. For these mental phenomena, the mind is aware of them in other ways: it is aware of them in the sense that it registers them and reacts to them all the time, but it does not have the awareness and experiences of what those phenomena are like and cannot share the information of the phenomena to its various parts that include the cognition part, the symbolizing part and the storage part (thus, the mind cannot think about, analyze, compare, and do other mental activities with these phenomena intentionally, cannot symbolize them directly, and cannot memorize and recall them intentionally). That is, only characteristic #1 occurs, but characteristics #2 and #3 do not occur. Examples of these mental phenomena are mental phenomena that occur in the perceptions of the levels of blood constituents (sodium, H+, oxygen, sugar, hormones, etc.), in the mental control of autonomic rhythmic respiration, and in the mental control of autonomic reflexes (pupillary, oculovestibular, optokinetic, etc.). In these mental phenomena, the mind is aware of them in some ways, registers them, and reacts to them all the time, but the mind does not have the awareness and experiences of what they are like (e.g., what the various blood levels of sodium, H+, oxygen, etc. are like) and cannot share the information of these phenomena to its various parts that include the cognition part, the symbolizing part, and the storage part (thus, it cannot think about, analyze, compare, and do other mental activities with the various blood levels of sodium, H+, oxygen, etc. intentionally, cannot symbolize them directly*, and cannot memorize and recall them intentionally).
(*It should be noted that, in reality, we can represent the blood levels of various blood constituents with various symbols, but that is indirect symbolization. We do not symbolize the blood levels that we are aware of and experience in our mind directly but instead symbolize the blood levels that are measured by our instruments and subsequently displayed to be seen by us or made known to us by other means.)
Therefore, some mental phenomena are consciously experienceable; but some are not. In this theory, mental phenomena that are consciously experienceable, with the described three important characteristics, will be called qualia (pleural form) or quale (singular form).
Definition. A mental phenomenon that is consciously experienceable is a quale.
And, in this theory, the term quale (pleural form: qualia) will be used to mean only this mental phenomenon.
Definition. A quale is a mental phenomenon that is consciously experienceable.
Now, manifestation-wise, characteristic #2 specifies that the mind has the awareness and experiences of what the qualia are like (what the vision of the house is like, what the sound of the song is like, what the odor of the rose is like, what the thinking of something is like, what the feeling of happiness is like, etc.), so qualia must manifest what they are like in the mind. This characteristic of qualia – manifesting what they are like in the mind – is very important: it differentiates qualia from all other mental phenomena that do not manifest what they are like in the mind, and it is the characteristic that is the basis of the hard problem of qualia: why and how qualia manifest what they are like in the mind. This characteristic is called phenomenal characteristic [8,9] or, in short, phenomenality**. Because qualia have this important characteristic, the terms phenomenal quale/qualia will be used when this characteristic is to be emphasized, but it should be noted that both quale/qualia and phenomenal quale/qualia mean the same in this theory.
(** Other similar terms in the literature are phenomenal character [1,4,8,10-12], or phenomenal properties [1,2,4,6-8,11,13].)
Other important characteristics of a quale that are inherent in its phenomenality or its manifesting what it is like in the mind are that each quale is unique in its manifestation (the quale’s manifestation is different from those of other qualia and other phenomena) and ineffable or not describable based on anything else (it cannot be described based on anything else and must be consciously experienced by a person for the person to know “what the quale is like” for him/herself). For example, the vision of the house and the sound of the song, which are qualia, are unique in their manifestations (i.e., the vision and the sound in one’s mind are different from each other and from other qualia and other phenomena such as the smell, the happy emotion, and the thought of past events) and not describable based on anything else (e.g., one cannot describe to a congenitally blind person what the vision of the house is like based on what the sound, the smell, the touch, and other perceptions are like; nor can one describe to a congenitally deaf person what the sound of the song is like based on what the vision, the smell, the touch, and other perceptions are like – they must be consciously experienced by a person for the person to know “what the vision of the house” is like and “what the sound of the song” is like for him/herself).
In summary, characteristic #2 of being consciously experienceable means that a quale manifests what it is like in the mind or has phenomenality, with uniqueness in its manifestation and ineffability.
Each quale may be complex and composed of several basic qualia of the same kind. For example, the vision of the house is complex and composed of several basic visual-kind qualia, such as color, shape, and brightness, etc.; while the sound of the song is complex and composed of several basic auditory-kind qualia, such as pitch, timbre, and loudness; and the rose odor is complex and composed of two basic olfactory-kind qualia, i.e., odor’s quality and strength. Like the complex qualia, each of these basic qualia – color, shape, pitch, timbre, odor’s quality, etc. – has phenomenality, with uniqueness in its manifestation and ineffability.
Etymologically, quale and qualia are the terms that derive from a Latin word meaning for “what sort” or “what kind” [9,12,14]. Although the terms quale and qualia were first used in philosophy in 1929 by Lewis CI in a discussion of sense-data theory [5,11,12,15] and later by a lot of philosophers to describe and discuss this kind of phenomenon philosophically [1-7,11-13,16-17], at present, these two terms are also used widely in cognitive neuroscience and related fields by many scientists in attempts to explain these phenomena physically [9,18-33]. However, the meaning of these terms can vary from author to author [5,6,12]. Therefore, to avoid confusion and uncertainty regarding what they mean in this theory, the working definitions of these two terms in this theory will specifically be as stated above.
3.2. Conscious awareness and conscious experience
As discussed above, when the mind is aware of and experiences a mental phenomenon that is consciously experienceable, there is a special kind of mental awareness and mental experience occurring: the mental awareness and mental experience that are associated with the three important characteristics as stated in 3.1. In this theory, this special kind of mental awareness and experience will be called conscious awareness and conscious experience, respectively. Thus, conscious awareness is mental awareness of a mental phenomenon that is consciously experienceable and a conscious experience is a mental experience of a mental phenomenon that is consciously experienceable. But, because a mental phenomenon that is consciously experienceable is a quale by definition, conscious awareness is mental awareness of a quale and a conscious experience is a mental experience of a quale. This is the definition of both terms in this theory.
Definition. Conscious awareness is mental awareness of a quale.
Definition. A conscious experience is a mental experience of a quale.
(The term conscious experience is used in the literature with this same or similar meaning by various authors [2,6,9,21,34-39]. Other similar or closely related terms in the literature are phenomenal experiences [9-12,24] and phenomenal consciousness [2,4-7,10-12,40].)
Now, when conscious awareness and a conscious experience of a quale occur, there occur
- the awareness of the existence of the conscious awareness and the conscious experience of the quale, and this existence is registered into the information and the processing systems of the mind;
- the awareness and experience of what the conscious awareness and the conscious experience of the quale are like; and
- the awareness and experience in 2. can be shared to the mind’s various parts, such as the cognition part, the symbolizing part, and the storage part.
Hence, conscious awareness and a conscious experience of a quale themselves are consciously experienceable; they themselves thus are qualia. This property will help identify what conscious awareness and a conscious experience physically are, which will be discussed in detail in Chapter 5 and Chapter 6. Also, because conscious awareness and a conscious experience are mental phenomena that can induce the feeling of what themselves are like in the mind, with uniqueness in their manifestations and ineffability, conscious awareness and a conscious experience, like other qualia, have phenomenal characteristics or phenomenality. So, when this aspect of having phenomenality is to be emphasized, the term phenomenal conscious awareness and phenomenal conscious experience will be used instead of conscious awareness and phenomenal conscious experience, but they mean the same in this theory.
As any conscious experience of a quale (such as an experience of a vision of a house) occurs in the mind of the subject who is having the experience, the experience is limited to only that subject, and only that subject knows what the experience is like (such as what the experience of the vision of the house is like). Although other subjects can each have a conscious experience of a similar quale (such as an experience of a vision of the same house) and know what it is like for himself/herself, he/she can never have another subject’s conscious experience and can never know exactly what another subject’s conscious experience is like (such as what another subject’s experience of the vision of the house is like). Therefore, each conscious experience is exclusively limited to the subject who has the experience and may be different among different subjects. A conscious experience is thus, in this sense, subjective. Because of this, a conscious experience may be called a subjective experience or subjective conscious experience [3,4,9,36-38,41,42]. In this theory, however, the author considers that the conscious part is essential for the experience of a quale to occur as it is (i.e., as a conscious experience, not as an unconscious experience) while the subjective part just occurs by the nature of the experience, so this kind of experience will be simply called a conscious experience.
3.3. Conscious vs unconscious awareness and experiences
Now let’s examine in more detail the differences between “conscious awareness and experiences” and “unconscious awareness and experiences” (from now on, when conciseness is required, the term “conscious awareness and experience” will be used instead of “conscious awareness and a conscious experience”, and the term “unconscious awareness and experience” will be used instead of “unconscious awareness and an unconscious experience”, and similarly for the plural cases) and how we know which kind of awareness and experiences occur.
The unconscious awareness and experiences occur in awareness and experiences of mental phenomena that represent
- some internal information, such as a) various blood levels of electrolytes, oxygen, sugar, hormones, and other blood constituents, b) some internal sensation, e.g., the pressure in atrium and carotid sinus, the tension of muscle fibers, and the tension of tendons, and c) the autonomic functions, the brain stem functions, the cerebellar functions, and many deep cerebral nuclei functions or
- some external information, such as the unconscious information in the case of subliminal perception [43-46], binocular rivalry [47-54], attentional blink [55-58], inattentional blindness [59-62], blindsight [63-66], and various unconscious cerebral processes (e.g., unconscious attention, unconscious thinking, unconscious reading, unconscious visual perception, unconscious face recognition, unconscious error detection, unconscious mathematical operation, unconscious situation analysis, unconscious memory and unconscious decision. [23,53,67-80]).
In these unconscious cases, although the mind registers these phenomena into its information and processing systems (characteristic #1 in section 3.1 occurs) and reacts to them, there are no conscious awareness and experiences of what these mental phenomena are like occurring (characteristic #2 in section 3.1 does not occur) and the mind cannot share information of these mental phenomena to the various mental parts that include the cognition part, the symbolizing part, and the storage part, i.e., the mind cannot intentionally analyze or compare them, symbolize them in some ways, and memorize and recall them (characteristic #3 in section 3.1 does not occur).
The conscious awareness and experiences occur in awareness and experiences of mental phenomena of the final perceptions of all external information (e.g., visual, auditory, and olfactory sensations) and some internal information (e.g. equilibrium and proprioceptive sensations) and of the highest-level cognitive information processing (thinking, having emotion, recalling memory, etc.). In these conscious cases, all the three important characteristics in section 3.1 occur: the mind registers and is aware of these mental phenomena’s existence (characteristic #1 in section 3.1 occurs), the mind has the awareness and experiences of what they are like (characteristic #2 in section 3.1 occurs), and the mind share information of these mental phenomena to the various mental parts that include the cognition part, the symbolizing part, and the storage part, i.e., the mind can intentionally analyze or compare them, symbolize them in some ways, and memorize and recall them (characteristic #3 in section 3.1 occurs).
Therefore, the principle differences between the two kinds of awareness and experience are that, in the unconscious cases, (1) there are no awareness and experiences of what the mental phenomena are like occurring and (2) the information of the phenomena is not distributed extensively to various cognitive mental processes that include the cognition part, the symbolizing part, and the storage part, while the opposite happens in the conscious cases. The extensive distribution of information, (2), makes the quale reportable by a conscious subject by using verbal, written, or other sign languages. So, if a person is normal (has no disabilities), he/she can be simply asked whether he/she knows that he/she has the awareness and an experience of something (e.g. the blood level of sodium at 130 mEq/L vs a vision of a house) and of what that something is like. The answer will be no for unconscious awareness and experience (such as in the case of blood level of sodium at 130 mEq/L) but will be yes for conscious awareness and an experience (such as in the case of a vision of a house).
More objectively or in the case that the person cannot answer the question (due to some disabilities, such as generalized paralysis, aphasia, or deafness and blindness), whether conscious awareness and experiences occur when a subject turns his/her attention to something can be ascertained by neurophysiological studies. It has been found from experiments that, when something has gained access into consciousness and conscious awareness and experiences of that thing occur, these neural phenomena will occur [18,20,21,24,27,28,30,81-88]
- A sudden intense ignition of widespread neural activities, especially those of bilateral prefrontal and parietal regions.
- The appearance of a slow wave, P300 wave, over the vertex of the head, about 300 – 500 milliseconds after the stimulus onset.
- A massive increase in high frequency gamma-band oscillation, starting around 150 – 300 milliseconds after the stimulus onset.
- Massive synchronization of electromagnetic signals across distant cortical regions, also starting around 300 milliseconds after the stimulus onset.
Other neural phenomena have also been found to occur with conscious awareness and experiences. These phenomena are the neural signatures of conscious awareness and experiences. Although it is not settled at present which combination of these phenomena is necessary and sufficient to indicate that conscious awareness and experiences have occurred, it is very likely that conscious awareness and experiences are associated with some specific combination of these phenomena and that this specific combination will be found in the future. Also, because qualia induce the occurrences of conscious awareness and experience, ultimately, qualia can be defined objectively as a non-material, mental phenomenon that can induce some specific combination of the above phenomena. Despite this exciting prospect, it should always be remembered that, basically, a quale is a mental phenomenon that is consciously experienceable, because this property will help us identify its nature.
3.4. Quale vs conscious experience
It is to be noted that in the literature the terms quale (qualia) and conscious experience may be used interchangeably to mean a mental phenomenon that is consciously experienceable (such as a vision of a house) or a conscious experience of the mental phenomenon (such as a conscious experience of the vision of the house) or both. That is, in some literature, there is no distinction between the two terms and between the two phenomena – which can be confusing. So, the reader has to be careful which phenomenon is being discussed at that point in the literature and which meaning is being used for that term.
However, current knowledge in neurophysiology indicates that, although the two phenomena – quale and conscious experience – are closely related functionally and sometimes overlapping (in the case of conscious awareness and experiences, because conscious awareness and experiences themselves are also qualia), they are different. All qualia except conscious awareness and experiences occur with neural processes that are different from those of conscious awareness and experiences, and these two kinds of phenomenon can change independently of each other. For example, a visual quale of a house occurs with the visual perception neural processes in various visual perception areas while a conscious experience of the visual quale of the house occurs with the synchronization between the consciousness neural process and the visual perception neural processes that the visual quale of the house occurs with [18,28,86,89,90]. Separate disturbances in the neural processes that a quale occurs with without disturbing the consciousness neural process, which a conscious experience occur with, can occur, and vice versa. For example, when a person is consciously experiencing the visual and the auditory qualia of his/her surroundings, if there is an acute stroke affecting the right occipital lobe or the left ventromedial occipital cortex, resulting in left hemianopia or right hemi-achromatopsia, respectively, the person’s visual qualia will be correspondingly affected, but his/her overall conscious experiences will still be intact, as is evident by the fact that he/she can still be consciously experiencing the auditory and the remaining visual qualia normally. On the other hand, if the person becomes drowsy, his/her conscious experiences of the visual and auditory qualia of the surroundings will become less and less and fade away while the qualia themselves are still undisturbed. That is, the manifestations of the visual and the auditory qualia are not disturbed. For example, visual qualia remain visual qualia (i.e., do not change to auditory qualia or other qualia), all basic qualia of the visual qualia (such as color, brightness, and shape) remain the same (i.e., do not change to other basic qualia), the details of visual qualia remain the same (for example, the visual qualia of the house retain all their details – colors, shape, size, etc. – and do not change to the visual qualia of something else, e.g., cars, trees, or animals), and deficits in qualia details such as hemianopia and hemi-achromatopsia do not occur. Therefore, in this theory, the two phenomena – qualia and conscious experiences – are two different phenomena and will be referred to with separate terms:
– Only quale, not any other term, will be used for a mental phenomenon that is consciously experienceable, and quale will be used to refer to only this phenomenon, not anything else. (Qualia will be used in plural cases.)
– Only conscious experience, not any other term, will be used for a mental experience of a quale, and conscious experience will be used to refer to only this mental experience, not anything else.
3.5. Types of qualia
All mental phenomena that are consciously experienceable are qualia, and there are many kinds of them. They can be classified into two types:
1. Sensory perception qualia
– External sensory perception qualia
– Internal sensory perception qualia
2. Cognition-emotion qualia
1. Sensory perception qualia are qualia that occur in perceptions of sensations. They can be subdivided into external sensory perception qualia and internal sensory perception qualia. External sensory perception qualia are qualia that occur in perceptions of sensations that occur from stimuli outside the body. In humans, there are several kinds of external sensory perception quale: visual, auditory, olfactory, gustatory, and somatosensory perception qualia. Internal sensory perception qualia are qualia that occur in perceptions of sensations that occur from stimuli inside the body. In humans, there also are several kinds of them: vestibular, proprioceptive, and visceral sensory perception (i.e., visceral pain, distension, cramps, nausea, etc.) qualia. It is possible that some animals that have sensory modalities that human beings do not, such as magnetoreceptionin birds, bats, bees, and sharks [91-93] or electroreception in electric fish [94-99], have other kinds of quale for these sensory perceptions too. Each kind of sensory perception quale has unique manifestation, cannot be described based on any other qualia or anything else, and must be consciously experienced to know what it is like for oneself (e.g., what the vision is like, what the sound is like, what the magnetoreception is like, or what the electroreception is like). Each kind of sensory perception quale may consist of several components that are basic qualia. For example, visual qualia consist of several basic qualia – color, brightness, shape, and other basic visual qualia – while auditory qualia consist of several other basic qualia – pitch, timbre, loudness, and other basic auditory qualia. Each component or each basic quale has unique manifestation, cannot be described based on any other basic qualia or anything else, and must be consciously experienced to know what it is like for oneself (e.g., for visual qualia: what the color is like, what the brightness is like, or what the shape is like). Sensory perception qualia, both external and internal, are information about something in the outside world. They are usually vivid in their manifestations.
It is important to note that not all perceptions of sensations that occur inside the body have qualia occurring. In fact, perceptions of a majority of internal sensations, which convey information from various organs or tissue inside the body, such as pressure in the blood vessels (sensed by baroreceptors in carotid sinuses and the aortic arch), blood oxygen level (sensed by chemoreceptors in the carotid body and the aortic body), blood pH and carbon dioxide level (sensed by chemoreceptors in the medulla), and various hormone levels (sensed by various hormone receptors), do not have qualia occurring, and we never know what their manifestations are like, i.e., what various blood pressure levels are like, what various blood pH are like, what various hormone levels are like, etc. Similarly, it is important to note that sensory perception qualia do not occur in all stages of perceptions but occur only in the final stages of perceptions, such as the final stages of a visual perception – which create visual qualia of color, brightness, shape, etc. – and the final stages of an auditory perception – which create sound qualia of pitch, timbre, loudness, etc. All the earlier stages of sensory perceptions, such as the first stage of processing raw sensory signals that arrive at the primary sensory perception area, do not have qualia, and we do not know what their manifestations are like, i.e., what these sensory signals are like at these early stages (such as, what the visual signals are like at the primary visual cortex and what the auditory signals are like at the primary auditory cortex). The fact that some sensory perceptions have qualia while some do not and the fact that qualia occur only in the final stages of sensory perception can give clues to why and how qualia and conscious experience occur. This point will be discussed in more detail in the next three chapters.
2. Cognition-emotion qualia are qualia that occur in mental processes that perform cognition or emotion functions. They occur in cognitive perceptions (such as perception of time, of existence, of self, and of non-self), cognitive executive functions (such as thinking of something, reliving past events, planning actions, making decisions, and controlling volitional movement), and emotion functions (such as feeling happy, sad, or angry). Like sensory perception qualia, each kind of these qualia has unique manifestations, cannot be described based on any other qualia or anything else, and must be consciously experienced to know what it is like for oneself (e.g., what the perception of time is like, what the thinking is like, or what the feeling of happiness is like). Cognition-emotion qualia are information about conscious activities of cognition or emotion. They are usually not as vivid in their manifestations as sensory perception qualia do.
Once more, it is important to note about the selectivity of qualia occurrences. All of the cognition-emotion qualia occur exclusively in the highest-level mental processes. All the lower-level mental processes, which comprise the vast majority of mental processes, such as the mental processes of the basal ganglia, brainstem nuclei, and cerebellum, do not have qualia, and we never know what their manifestations are like, i.e., what the extrapyramidal motor control is like, what the cerebellar motor control is like, what the autonomic control of body temperature, heart rate, various blood constituents, etc. is like, and so on. Again, the fact that the highest-level cognitive mental processes have qualia while the lower-level mental processes do not gives clues to why and how qualia and conscious experience occur. This point, too, will be discussed in more detail in the next three chapters.
3.6. Sensory perception qualia as representations of the outside world
A sensory perception quale of the outside world, such as a vision of a house, a sound of a song, or an odor of a rose in one’s mind, may seem real; however, it is not that physical thing. It is just a mental phenomenon of a sensory perception mental process, which occurs with a sensory perception neural process, to represent that thing in the outside world. But because the process of neural perception of the outside world depends on many factors, such as in the case of a visual perception of a house: the external physical factors (the light that illuminates the house, the medium through which the light must pass, the distance between the house and the eyes, etc.), the internal anatomical properties of the whole visual pathway (from the corneas to the visual perception areas in the brain), and the physiologic functions of the whole visual pathway (from the generation of visual signals in the retina through several steps of signal processing in various visual perception neural processes to the final step of signal processing in the final visual perception neural process), the final neural perception of the outside world and the associated mental perception and quale usually do not represent the outside world identically in detail but are just approximate and modified representations of it. As the details of the neural perception and of the quale are the information about the outside world, the final information that is contained in the neural perception and the quale is not identical with that of the outside world. Sometimes, the inaccuracy produced in the perception may be so great that it results in an illusion, or there may be a perception system anomaly that causes a different perception to occur with the primary perception and results in a condition called synesthesia [100-104].
Some examples of qualia with inaccuracy in representing the outside world are as follows:
– The visual quale of a house when one looks at the house at a distance does not contain the complete visual details of the house, such as a nail in the house wall, a patch of dirt on the door, or a small crack in a window – this inaccuracy occurs as a result of an external physical factor (the distance) combined with an internal physiologic property (the limited spatial resolution of the retina). So, the visual quale of a house is neither the physical house itself nor the exact representation of the physical house.
– Various visual illusions occur physiologically in normal people, such as the finger sausage illusion in Figure 3.2.
Figure 3.2 Finger sausage illusion.
Finger sausage illusion. A – the fingers as appeared when looked at directly and B – the fingers as appeared when one looks at the background beyond the fingers. Although the visual quale of the fingers (or the fingers as we see in our mind) changes, depending on where we focus our sight, the fingers themselves cannot physically change by just changing the sight’s focus. This proves that the visual quale of the fingers (or the fingers as we see in our mind) is neither the fingers that we are seeing nor the exact representation of the fingers that we are seeing.
– An auditory illusion quale of a third tone, a binaural beat, can be heard when two different pure-tone sine waves with frequencies lower than 1,500 Hz and less than 40 Hz difference between them are presented separately through each ear – this illusion is created physiologically in the auditory perception system [105-109]. So, the binaural beat quale that occurs is neither anything that really exists nor a representation of anything that really exists.
– A color perception quale occurs together with an auditory perception quale when a person who has sound-color synesthesia hears a musical sound. This additional visual quale is created by a neural connection anomaly between the auditory and the visual perception systems [110-112]. So, the visual quale that occurs is neither anything that really exists nor a representation of anything that really exists.
In representing the outside world, the inaccuracy of a neural process’s perception and the inaccuracy of its associated quale involve all details of the outside world, not only the physical details as discussed above but also the temporal details. For example, in the case of a visual perception of a house, it takes time from the moment the house reflects off light signals to the moment the visual neural processes perceive it and the visual quale of the house occurs. So, the house that we see in the mind is not the real-time house but the house a few milliseconds ago. This can be very obvious in the case of very distant objects, for example, the sun we see in our minds is not a real-time sun but an 8-minute-ago sun at an 8-minute-ago position in the sky, and this is similarly true for all other celestial objects: the planets, the stars, the supernovas, etc. Also, a temporal inaccuracy may arise physiologically from the work of neural processes themselves, such as the prolongation of time that we feel in the stopped-clock illusion [113-116].
In summary, a sensory perception quale occurs with the function of a sensory perception neural process to represent a physical thing in the outside world but is not the physical thing itself. As there are many factors that affect the process of neural perception of the outside world, the details of the resulting neural perception and its quale are not exactly identical with the details of the outside world. Thus, a sensory perception quale is just an approximate, modified representation of something in the outside world, and illusion qualia or synesthetic qualia, which represent nothing real in the outside world, may also occur.
If qualia are just representations of things in the external world, what are those things in the external world really like by themselves?
Things in the external world do not have color, shape, size, dimension, hardness, odor, etc. as they appear in our minds by themselves; they just have properties that can create qualia (color, shape, size, dimension, hardness, odor, etc.) in a being’s nervous system and mind via the being’s sensory perception systems. The qualia of a thing in the outside world may be different in different beings, but none of the qualia are that thing or can be claimed to be the only correct representations of that thing.
In Figure 3.3, the man, the woman, the dog, or the bee cannot claim that his/her/its perception quale of the house is the house or that his/her/its perception quale of the house is the only one that is the correct representation of that house and that others’ perception qualia are wrong representations.
Figure 3.3 Qualia among different subjects
Similarly, perceptions of space, time, and existence are not what space, time, and existence are either. The former entities are just mental phenomena that are created to represent the latter entities, but they are not the same ones. Thus, our world and our existence as we feel them are not what they really are; what they really are can never be felt or perceived via our sensory perception systems.
What things in the outside world, space, time, and existence are like by themselves is an unanswerable question because what those things are like is not absolute but observer-dependent. If there is no observer to judge what they are like (i.e., in the question of what they are like by themselves), then the question of what they are like is meaningless. However, what those things really are by themselves is an answerable question. The answer is that they are entities with properties that can create sensory perception qualia, which manifest themselves as vision, sound, space, time, etc., in some entities that have signal-processing systems that can create qualia, such as humans or some other animals. Hence, the correct depiction of Figure 3.3 is, in fact, Figure 3.4.
Figure 3.4 Qualia exist only in the minds
The man, the woman, the dog, the bee, and the house do not have shape, size, color, etc., as we perceive them, by themselves. Shape, size, color, etc. of all things exist in the mind of the observers only
This chapter is a long chapter and involve many definitions of specific terms. The most important of them are definitions of qualia, conscious awareness, and conscious experiences. To summarize, they are defined as follows:
– A mental phenomenon is consciously experienceable if, when the mind is aware of and experiences the mental phenomenon, the three important characteristics as stated in section 3.1 occur.
– A quale is a mental phenomenon that is consciously experienceable.
– Conscious awareness is mental awareness of a mental phenomenon that is consciously experienceable, i.e., mental awareness of a quale – it is mental awareness that has the three important characteristics as stated in section 3.1 occurring.
– A conscious experience is a mental experience of a mental phenomenon that is consciously experienceable, i.e., a mental experience of a quale – it is a mental experience that has the three important characteristics as stated in section 3.1 occurring.
The next chapter (Chapter 4 – Theorem III) will examine and establish whether qualia are physical phenomena or not, and the following chapter (Chapter 5 – Theorem IV) ) will examine and find the true nature of qualia, answer the interesting question of whether what you see as red in your mind can appear as blue, green, or other colors in other people’s minds, and answer the hard problem and the explanatory gap of qualia.
- Chalmers DJ. Consciousness and its place in nature. In: Chalmers DJ, editor. Philosophy of mind: Classical and contemporary readings. Oxford: Oxford University Press; 2002. ISBN-13: 978-0195145816 ISBN-10: 019514581X. http://consc.net/papers/nature.html
- Chalmers DJ. Facing up to the problem of consciousness. J Conscious Stud. 1995;2(3):200-219. http://consc.net/papers/facing.html
- Chalmers DJ. Moving forward on the problem of consciousness. J Conscious Stud. 1997;4(1):3-46. http://consc.net/papers/moving.html
- Gennaro RJ. Consciousness. Internet Encyclopedia of Philosophy. Retrieved 2017 Apr 18 from http://www.iep.utm.edu/consciou/
- Sturm T. Consciousness regained? Philosophical arguments for and against reductive physicalism. Dialogues Clin Neurosci. 2012 Mar;14(1):55–63. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3341650/
- Van Gulick R. Consciousness. In: Zalta EN, editor. The Stanford Encyclopedia of Philosophy (Summer 2017 Edition). Retrieved 2017 Sep 8 from https://plato.stanford.edu/archives/sum2017/entries/consciousness/
- Weisberg J. The hard problem of consciousness. The Internet Encyclopedia of Philosophy. https://www.iep.utm.edu/hard-con/
- Dainton B. Temporal consciousness. In: Zalta EN, editor. The Stanford Encyclopedia of Philosophy (Fall 2017 Edition). Retrieved 2018 Feb12 from https://plato.stanford.edu/archives/fall2017/entries/consciousness-temporal/
- Kanai R, Tsuchiya N. Qualia. Current Biology. 2012 May 22;22(10):R392–R396. DOI: http://dx.doi.org/10.1016/j.cub.2012.03.033 . http://www.cell.com/current-biology/fulltext/S0960-9822(12)00320-X
- Jacob P. Intentionality. In: Zalta EN, editor. The Stanford Encyclopedia of Philosophy (Winter 2014 Edition). https://plato.stanford.edu/archives/win2014/entries/intentionality/
- Kind A. Qualia. Internet Encyclopedia of Philosophy. Retrieved 2017 Apr 5 from http://www.iep.utm.edu/qualia/
- Tye M. Qualia. In: Zalta EN, editor. The Stanford Encyclopedia of Philosophy (Winter 2017 Edition). Retrieved 2018 Jan 05 from https://plato.stanford.edu/archives/win2017/entries/qualia/
- Chalmers DJ. Absent qualia, fading qualia, dancing qualia. In Metzinger T, editor. Conscious Experience. Ferdinand Schoningh. 1995. p 309–328. http://consc.net/papers/qualia.html
- Philosophy Terms. Qualia. Retrieved 2019 Dec 19 from https://philosophyterms.com/qualia/
- Johannesson AT. Qualia under scrutiny: On C. I. Lewis’s idea of qualia. 2014 Feb. https://www.academia.edu/8486432/Qualia_under_Scrutiny_On_C.I._Lewiss_Idea_of_Qualia
- Smart JJC. The mind/brain identiety theory. In: Zalta EN, editor. The Stanford Encyclopedia of Philosophy (Spring 2017 Edition). https://plato.stanford.edu/archives/spr2017/entries/mind-identity/
- Byrne A. Inverted qualia. In: Zalta EN, editor. The Stanford Encyclopedia of Philosophy (Winter 2016 Edition). Retrieved 2017 Jun 01 from https://plato.stanford.edu/archives/win2016/entries/qualia-inverted/
- Babiloni C, Marzano N, Soricelli A, Cordone S, Millán-Calenti JC, Percio CD, et al. Cortical neural synchronization underlies primary visual consciousness of qualia: Evidence from event-related potentials. Front Hum Neurosci. 2016;10:310. DOI: 10.3389/fnhum.2016.00310. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4927634/
- Balduzzi D, Tononi G. Qualia: The geometry of integrated information. Friston KJ, editor. PLoS Comput Biol. 2009 Aug; 5(8): e1000462. DOI: 10.1371/journal.pcbi.1000462. http://journals.plos.org/ploscompbiol/article?id=10.1371/journal.pcbi.1000462
- Baars BJ, Franklin S, Ramsoy TZ. Global workspace dynamics: Cortical “Binding and propagation” enables conscious contents. Front Psychol. 2013;4:200. DOI: 10.3389/fpsyg.2013.00200. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3664777/
- Edelman GM, Gally JA, Baars BJ. Biology of consciousness. Front Psychol. 2011;2:4. DOI: 10.3389/fpsyg.2011.00004. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3111444/
- Feinberg TE, Mallatt J. The evolutionary and genetic origins of consciousness in the Cambrian Period over 500 million years ago. Front Psychol. 2013;4:667. DOI: 10.3389/fpsyg.2013.00667. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3790330/
- Oizumi M, Albantakis L, Tononi G. From the phenomenology to the mechanisms of consciousness: Integrated Information Theory 3.0. PLoS Comput Biol. 2014 May;10(5):e1003588. DOI: 10.1371/journal.pcbi.1003588. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4014402/pdf/pcbi.1003588.pdf
- Orpwood R. Information and the Origin of Qualia. Front Syst Neurosci. 2017Apr 21;11(Article 22):1-16. DOI: 10.3389/fnsys.2017.00022. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5399078/pdf/fnsys-11-00022.pdf
- Orpwood R. Neurobiological mechanisms underlying qualia. J Integr Neurosci. 2007 Dec;6(4):523-540.
- Orpwood RD. Perceptual qualia and local network behavior in the cerebral cortex. J Integr Neurosci. 2010 Jun;9(2):123-152.
- Orpwood R. Qualia could arise from information processing in local cortical networks. Front Psychol. 2013;4:121. DOI: 10.3389/fpsyg.2013.00121. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3596736/
- Pollen DA. On the neural correlates of visual perception. Cereb Cortex. 1999; 9(1):4-19. DOI: https://doi.org/10.1093/cercor/9.1.4. https://academic.oup.com/cercor/article/9/1/4/314915/On-the-Neural-Correlates-of-Visual-Perception
- Ramachandran VS, William Hirstein W. Three laws of qualia. What neurology tells us about the biological functions of consciousness, qualia and the self. J Conscious Stud. 1997;4(5-6):429–458. http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.127.8130
- Seth AK, Baars BJ. Neural Darwinism and consciousness. Conscious Cogn. 2005 Mar;14(1):140-168. http://ccrg.cs.memphis.edu/assets/papers/2004/Seth%20&%20Baars,%20Neural%20Darwinism-2004.pdf
- Seth Ak, Izhikevich E, Reeke GN, Edelman GM. Theories and measures of consciousness: An extended framework. Proc Natl Acad Sci U S A. 2006 July 11;103(28):10799-10804. https://doi.org/10.1073/pnas.0604347103 http://www.pnas.org/content/103/28/10799.full
- Tononi G. An information integration theory of consciousness. BMC Neurosci 2004,5:42. DOI: 10.1186/1471-2202-5-42. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC543470/pdf/1471-2202-5-42.pdf
- Tononi G. Integrated information theory of consciousness: An updated account. Archives Italiennes de Biologie 2012 Jun-Sep;150(2-3):290-326. http://architalbiol.org/index.php/aib/article/viewFile/15056/23165867
- Carruthers P. Conscious experience versus conscious thought. In: Kriegel U, Kenneth Williford K, editors. MIT Press; 2005. http://faculty.philosophy.umd.edu/pcarruthers/Conscious-experience-versus-conscious-thought.pdf
- Chalmers DJ. A catalog of conscious experiences. In: The Conscious Mind. Oxford; Oxford University Press; 1996: 6-11. https://www.open.edu/openlearn/ocw/pluginfile.php/610558/mod_resource/content/1/reading1.pdf
- Chalmers DJ. The Puzzle of Conscious Experience. Scientific American. 1995 Dec;273(6):80-86. http://s3.amazonaws.com/arena-attachments/2382142/9247d5f1a845e5482b1bd66d82c3a9bf.pdf?1530582615
- Frith C, Perry R, Lumer E. The neural correlates of conscious experience: an experimental frame Trends Cogn Sci. 1999 Mar;3(3):105-114. http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.575.6134&rep=rep1&type=pdf
- Leisman G, Koch P. Networks of conscious experience: Computational neuroscience in understanding life, death, and consciousness. Rev Neurosci. 2009;20(3-4):151-176. https://www.researchgate.net/profile/Gerry_Leisman/publication/41449921_Networks_of_Conscious_Experience_Computational_Neuroscience_in_Understanding_Life_Death_and_Consciousness/links/0fcfd5023c1d28270d000000.pdf
- Wu W. The neuroscience of consciousness. In: Zalta EN, editor. The Stanford Encyclopedia of Philosophy (Winter 2018 Edition). Retrieved 2019 Dec 20 from https://plato.stanford.edu/entries/consciousness-neuroscience/
- Pernu TK. The five marks of the mental. Front Psychol. 2017;8:1084. DOI: 10.3389/fpsyg.2017.01084. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5500963/
- Aruab J, Bachmannc T, Singerabd W, Melloni L. Distilling the neural correlates of consciousness. Neuroscience & Biobehavioral Reviews. 2012 Feb;36(2):737-746. https://doi.org/10.1016/j.neubiorev.2011.12.003. https://www.sciencedirect.com/science/article/pii/S0149763411002107
- Baars BJ. Subjective experience is probably not limited to humans: The evidence from neurobiology and behavior. Conscious Cogn. 2005 Mar;14(1):7-21.
- Ionescu MR. Subliminal perception of complex visual stimuli. Rom J Ophthalmol. 2016 Oct-Dec;60(4):226–230. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5711286/
- Jacobs C, Sack AT. Behavior in oblivion: The neurobiology of subliminal priming. Brain Sci. 2012 Jun;2(2):225-241. doi: 10.3390/brainsci2020225. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4061795/?report=classic
- Elgendi M, Kumar P, Barbic S, Howard N, Abbott D, Cichocki Subliminal Priming—State of the Art and Future Perspectives. Behav Sci (Basel). 2018 Jun;8(6):54. doi: 10.3390/bs8060054. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6027235/?report=classic
- Ruch S, Züst MA, Henke K. Subliminal messages exert long-term effects on decision-making. Neurosci Conscious. 2016;2016(1):niw013. doi: 10.1093/nc/niw013. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6204644/?report=classic
- Blake R, Brascamp J, Heeger DJ. Can binocular rivalry reveal neural correlates of consciousness? Philos Trans R Soc Lond B Biol Sci. 2014 May 5;369(1641):20130211. doi: 10.1098/rstb.2013.0211. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3965165/
- Blake R, Wilson H. Binocular Vision. Vision Res. 2011 Apr 13;51(7):754-770. doi: 10.1016/j.visres.2010.10.009. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3050089/
- Dieter KC, Brascamp J, Tadin D, Blake R. Does visual attention drive the dynamics of bistable perception? Atten Percept Psychophys. 2016 Oct;78(7):1861–1873. doi: 10.3758/s13414-016-1143-2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5014653/
- Doesburg SM, Green JJ, McDonald JJ, Ward LM. Rhythms of consciousness: Binocular rivalry reveals large-scale oscillatory network dynamics mediating visual perception. PLoS One. 2009;4(7):e6142. doi: 10.1371/journal.pone.0006142. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2702101/
- Kang MS, Blake R. An integrated framework of spatiotemporal dynamics of binocular rivalry. Front Hum Neurosci. 2011;5:88. doi: 10.3389/fnhum.2011.00088. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3171066/
- Lin Z, He S. Seeing the invisible: The scope and limits of unconscious processing in binocular rivalry. Prog Neurobiol. 2009 Apr;87(4):195-211. doi: 10.1016/j.pneurobio.2008.09.002. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2689366/
- Rees G. Neural correlates of the contents of visual awareness in humans. Philos Trans R Soc Lond B Biol Sci. 2007 May 29;362(1481):877-886. doi: 10.1098/rstb.2007.2094. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2430003/
- Sterzer P, Stein T, Ludwig K, Rothkirch M, Hesselmann G. Neural processing of visual information under interocular suppression: A critical review. Front Psychol. 2014;5:453. doi: 10.3389/fpsyg.2014.00453. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4032950/
- Dux PE, Marois R. How humans search for targets through time: A review of data and theory from the attentional blink. Atten Percept Psychophys. 2009 Nov; 71(8): 1683-1700. doi: 10.3758/APP.71.8.1683. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2915904/
- Shen D, Vuvan DT, Alain C. Cortical sources of the auditory attentional blink. J Neurophysiol. 2018 Aug 1;120(2):812-829. doi: 10.1152/jn.00007.2018. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6139462/
- Willems C, Martens S. Time to see the bigger picture: Individual differences in the attentional blink. Psychon Bull Rev. 2016;23(5):1289-1299. doi: 10.3758/s13423-015-0977-2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5050248/
- Zivony A, Shanny S, Lamy D. Perceptual processing is not spared during the attentional blink. J Cogn. 2018;1(1):18. doi: 10.5334/joc.20. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6634390/
- Hyman IE, Jr., Sarb BA, Wise-Swanson BM. Failure to see money on a tree: Inattentional blindness for objects that guided behavior. Front Psychol. 2014;5:356. doi: 10.3389/fpsyg.2014.00356. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4005951/
- Kreitz C, Furley P, Memmert D, Simons DJ. Inattentional blindness and individual differences in cognitive abilities. PLoS One. 2015;10(8):e0134675. doi: 10.1371/journal.pone.0134675. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4530948/
- Usher M, Bronfman ZZ, Talmor S, Jacobson H, Eitam B. Consciousness without report: Insights from summary statistics and inattention ‘blindness’. Philos Trans R Soc Lond B Biol Sci. 2018 Sep 19;373(1755):20170354. doi: 10.1098/rstb.2017.0354. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6074079/
- Wright TJ, Roque NA, Boot WR, Cary Stothart C. Attention capture, processing speed, and inattentional blindnes Acta Psychol (Amst). 2018 Oct;190:72-77. doi: 10.1016/j.actpsy.2018.07.005. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6309252/
- Ajina S, Bridge H. Blindsight and unconscious vision: What they teach us about the human visual system. Neuroscientist. 2017 Oct;23(5):529–541. doi: 10.1177/1073858416673817. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5493986/
- Carota A, Calabrese P. The achromatic ‘philosophical zombie’, a syndrome of cerebral achromatopsia with color anopsognosia. Case Rep Neurol. 2013 Jan-Apr;5(1):98–103. doi: 10.1159/0003510. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3656676/
- Leopold DA. Primary visual cortex, awareness and blindsight. Annu Rev Neurosci. 2012;35:91–109. doi: 10.1146/annurev-neuro-062111-150356. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3476047/
- Silvanto J. Why is “blindsight” blind? A new perspective on primary visual cortex, recurrent activity and visual awareness. Conscious Cogn. 2015 Mar;32:15-32. doi: 10.1016/j.concog.2014.08.001. https://www.sciencedirect.com/science/article/pii/S1053810014001329
- Axelrod V, Bar M, Rees G, Yovel G. Neural correlates of subliminal language processing. Cereb Cortex. 2015 Aug; 25(8): 2160-2169. doi: 10.1093/cercor/bhu022. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4494027/?report=classic
- Bargh JA, Morsella E. The Unconscious Mind. Perspect Psychol Sci. 2008 Jan;3(1):73–79. DOI: 10.1111/j.1745-6916.2008.00064.x. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2440575/
- Bergström F, Eriksson J. Neural evidence for non-conscious working memory. Cerebral Cortex. 2018 Sep;28(9):3217–3228. https://doi.org/10.1093/cercor/bhx193. https://academic.oup.com/cercor/article/28/9/3217/4058206
- Creswell JD, Bursley JK, Satpute AB. Neural reactivation links unconscious thought to decision-making performance. Soc Cogn Affect Neurosci. 2013 Dec;8(8):863-869. doi: 10.1093/scan/nst004. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3831563/
- Dehaene S. Fathoming unconscious depths. In: Consciousness and the brain. Penguin Books. 2014. New York, New York, USA. ISBN 978-0-670-02543-5, 978-0-14-312626-3. p 47-88.
- Dijksterhuis A. First neural evidence for the unconscious thought process. Soc Cogn Affect Neurosci. 2013 Dec; 8(8): 845–846. doi: 10.1093/scan/nst036. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3831564/
- Dijksterhuis A, Strick M. A Case for thinking without consciousness. Perspect Psychol Sci. 2016 Jan;11(1):117-132. doi: 10.1177/1745691615615317. https://www.researchgate.net/publication/292188707_A_Case_for_Thinking_Without_Consciousness
- van Gaal S, Lamme VA. Unconscious high-level information processing: implication for neurobiological theories of consciousness. Neuroscientist. 2012 Jun;18(3):287-301. doi: 10.1177/1073858411404079. https://pdfs.semanticscholar.org/b9af/d0e8d460ba73cf197a96e2dd8b524e05390c.pdf
- Garrison KE, Handley IM. Not merely experiential: Unconscious thought can be rational. Front Psychol. 2017 Jul 6;8:1096. doi: 10.3389/fpsyg.2017.01096. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5498519/
- Horga G, Maia TV. Conscious and unconscious processes in cognitive control: A theoretical perspective and a novel empirical approach. Front Hum Neurosci. 2012;6:199. doi: 10.3389/fnhum.2012.00199. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3458455/
- Kiefer M, Ansorge U, Haynes JD, Hamker F, Mattler U, Verleger R, et al. Neuro-cognitive mechanisms of conscious and unconscious visual perception: From a plethora of phenomena to general principles. Adv Cogn Psychol. 2011;7:55–67. doi: 10.2478/v10053-008-0090-4. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3259028/
- Ritter SM, Dijksterhuis A. Creativity – The unconscious foundations of the incubation period. Front Hum Neurosci. 2014;8:215. doi: 10.3389/fnhum.2014.00215. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3990058/
- Vlassova A, Donkin C, Pearson J. Unconscious information changes decision accuracy but not confidence. Proc Natl Acad Sci U S A. 2014 Nov11;111(45):16214-16218. doi: 10.1073/pnas.1403619111. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4234611/
- Squire LR, Dede AJO. Conscious and Unconscious Memory Systems. Cold Spring Harb Perspect Biol. 2015 Mar;7(3):a021667. doi: 10.1101/cshperspect.a021667. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4355270/
- Engel AK, Singer W. Temporal binding and the neural correlates of sensory awareness. Trends in Cognitive Sciences. 2001 Jan;5(1):16-24. http://andreas-engel.com/engel_2001_tics.pdf
- Dehaene S, Changeux JP. Experimental and theoretical approaches to conscious processing. Neuron. 2011 Apr;70(2):200-227. DOI: 10.1016/j.neuron.2011.03.018. https://www.sciencedirect.com/science/article/pii/S0896627311002583
- Dehaene S, Charles L, King JR, Marti S. Toward a computational theory of conscious processing. Curr Opin Neurobiol. 2014 Apr;25:76–84. doi: 10.1016/j.conb.2013.12.005. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5635963/
- Dehaene S, Sergent C, Changeux JP. A neuronal network model linking subjective reports and objective physiological data during conscious perception. Proc Natl Acad Sci U S A. 2003 Jul 8;100(14):8520–8525. DOI: 10.1073/pnas.1332574100. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC166261/
- Del Cul A, Baillet S, Dehaene S. Brain dynamics underlying the nonlinear threshold for access to consciousness. PLoS Biol. 2007 Oct;5(10):e260. https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.0050260
- Fisch L, Privman E, Ramot M, Harel M, Nir Y, Kipervasser S, et al. Neural “Ignition”: Enhanced activation linked to perceptual awareness in human ventral stream visual cortex. Neuron. 2009 Nov 25;64(4):562–574. DOI: 10.1016/j.neuron.2009.11.001. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2854160/
- Lamy D, Salti M, Bar-Haim Y. Neural correlates of subjective awareness and unconscious processing: An ERP study. J Cogn Neurosci. 2009 Jul;21(7):1435-46. doi: 10.1162/jocn.2009.21064. https://www.researchgate.net/publication/23170315_Neural_Correlates_of_Subjective_Awareness_and_Unconscious_Processing_An_ERP_Study
- Melloni L, Molina C, Pena M, Torres D, Singer W, Rodriguez E. Synchronization of neural activity across cortical areas correlates with conscious perception. Journal of Neuroscience. 2007 Mar 14;27(11):2858-2865. DOI: https://doi.org/10.1523/JNEUROSCI.4623-06.2007. http://www.jneurosci.org/content/27/11/2858.long
- Lamme V, Roelfsema P. (2000). The distinct modes of vision offered by feedforward and recurrent processing. Trends in neurosciences. 2000 Nov; 23(11):571-579. DOI: 10.1016/S0166-2236(00)01657-X. https://www.researchgate.net/publication/12253934_The_Distinct_Modes_of_Vision_Offered_by_Feedforward_and_Recurrent_Processing
- Nani A, Manuello J, Mancuso L, Liloia D, Costa T, Cauda F. The neural correlates of consciousness and attention: Two sister processes of the brain. Front Neurosci. 2019;13:1169. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6842945/
- Beason RC, Dussourd N, Deutschlander ME. Behavioral evidence for the use of magnetic material in magnetoreception by a migratory bird. Journal of Experimental Biology. 1995;198:141-146. http://jeb.biologists.org/content/jexbio/198/1/141.full.pdf
- Holland RA, Kirschvink JL, Doak TG, Wikelski M. Bats use magnetite to detect the earth’s magnetic field. PLoS ONE. 2008 Feb 27;3(2):e1676. https://doi.org/10.1371/journal.pone.0001676 http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0001676
- Kirschvink JL, Gould JL. Biogenic magnetite as a basis for magnetic field detection in animals. Biosystems 1981;13(3):181-201. http://web.gps.caltech.edu/~jkirschvink/pdfs/Biosystems1981.pdf
- Chacron M. Electrolocation. Scholarpedia, 2007;2(1):1411. http://www.scholarpedia.org/article/Electrolocation
- Freitas R, Zhang G, Albert JS, Evans DH, Cohn MJ. Developmental origin of shark electrosensory organs. Evol Dev. 2006 Jan-Feb;8(1):74-80.
- Hofmann V, Sanguinetti-Scheck JI, Künzel S, Geurten B, Gómez-Sena L, Engelmann J. Sensory flow shaped by active sensing: sensorimotor strategies in electric fish. J Exp Biol. 2013 Jul 1;216(Pt 13):2487-2500. doi: 10.1242/jeb.082420. https://jeb.biologists.org/content/216/13/2487.long
- Pereira AC, Caputi AA. Imaging in electrosensory systems. Interdiscip Sci. 2010 Dec;2(4):291-307.
- von der Emde G, Schwarz S. Three-dimensional analysis of object properties during active electrolocation in mormyrid weakly electric fishes (Gnathonemus petersii). Philos Trans R Soc Lond B Biol Sci. 2000 Sep 29;355(1401):1143–1146. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1692845/pdf/11079386.pdf
- von der Emde G. Active electrolocation of objects in weakly electric fish. J Exp Biol. 1999 May;202(# (Pt 10)):1205-1215. https://jeb.biologists.org/content/jexbio/202/10/1205.full.pdf
- Banissy MJ, Jonas C, Kadosh RC. Synesthesia: An introduction. Front Psychol. 2014;5: 1414. DOI: 10.3389/fpsyg.2014.01414. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4265978/
- Hubbard EM. Neurophysiology of synesthesia. Curr Psychiatry Rep. 2007 Jun;9(3):193-199. https://www.hal.inserm.fr/file/index/docid/150599/filename/Hubbard_CurrPsychReports.pdf
- Hubbard EM, Ramachandran VS. Neurocognitive mechanisms of synesthesia : A review. Neuron. 2005 Nov 3;48:509–520. DOI: 10.1016/j.neuron.2005.10.012. http://cbc.ucsd.edu/pdf/neurocog_synesthesia.pdf
- Rouw R, Scholte HS, Colizoli O. Brain areas involved in synaesthesia: A review. J Neuropsychol. 2011 Sep;5(2):214-242. DOI: 10.1111/j.1748-6653.2011.02006.x. http://mobile.www.daysyn.com/Rouwetal2011.pdf
- Ward J, Mattingley JB. Synaesthesia: An overview of contemporary findings and controversies. Cortex. 2006 Feb;42(2):129-136. http://acces.ens-lyon.fr/acces/thematiques/neurosciences/actualisation-des-connaissances/memoire-attention-et-apprentissage/neuros_apprentissage/neuro_apprentiss_2/dossier_hupe/Ward
- Draganova R, Ross B, Wollbrink A, Pantev C. Cortical steady-state responses to central and peripheral auditory beats. Cereb Cortex. 2008 May;18(5):1193-1200. https://academic.oup.com/cercor/article/18/5/1193/349492
- Grose JH, Buss E, Hall JW. Binaural beat salience. Hear Res. 2012 Mar;285(1-2):40–45. DOI: 10.1016/j.heares.2012.01.012. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3299837/
- Jirakittayakorn N, Wongsawat Y. Brain responses to a 6-Hz binaural beat: Effects on general theta rhythm and frontal midline theta activity. Front Neurosci. 2017;11:365. DOI: 10.3389/fnins.2017.00365. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5487409/
- Karino S, Yumoto M, Itoh K, Uno A, Yamakawa K, Sekimoto S, et al. Neuromagnetic responses to binaural beat in human cerebral cortex. Journal of Neurophysiology. 2006 Oct 1;96(4):1927-1938. DOI: 10.1152/jn.00859.2005. http://jn.physiology.org/content/96/4/1927.long
- Pratt H, Starr A, Michalewski HJ, Dimitrijevic A, Bleich N, Mittelman N. Cortical evoked potentials to an auditory illusion: Binaural beats. Clin Neurophysiol. 2009 Aug;120(8):1514–1524. DOI: 10.1016/j.clinph.2009.06.014. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2741401/
- Neufeld J, Sinke C, Dillo W, Emrich HM, Szycik GR, Dima D, et al. The neural correlates of coloured music: A functional MRI investigation of auditory–visual synaesthesia. Neuropsychologia. 2012; 50: 85-89. http://www.daysyn.com/neufeld_j_et_al_2012.pdf
- Neufeld J, Sinke C, Zedler M, Dillo W, Emrich HM, Bleich S, et al. Disinhibited feedback as a cause of synesthesia: Evidence from a functional connectivity study on auditory-visual synesthetes. 2012 Jun;50(7):1471-1477.
- Zamm A, Schlaug G, Eagleman DM, Loui P. Pathways to seeing music: Enhanced structural connectivity in colored-music synesthesia. Neuroimage. 2013 Jul 1;74:359–366. DOI: 10.1016/j.neuroimage.2013.02.024. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3643691/
- Eagleman DM. Human time perception and its illusions. Curr Opin Neurobiol. 2008 April;18(2):131–136. DOI: 10.1016/j.conb.2008.06.002. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2866156/pdf/nihms-73539.pdf
- Lin YJ, Shimojo S. Triple dissociation of duration perception regulating mechanisms: Top-down attention is inherent. PLoS One. 2017;12(8): e0182639. DOI: 10.1371/journal.pone.0182639. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5549740/pdf/pone.0182639.pdf
- van Wassenhove V, Wittmann M, Craig AD, Paulus MP. Psychological and neural mechanisms of subjective time dilation. Front Neurosci.2011;5: 56. DOI: 10.3389/fnins.2011.00056. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3085178/
- Yarrow K, Johnson H, Haggard P, Rothwell JC. Consistent chronostasis effects across saccade categories imply a subcortical efferent trigger. J Cogn Neurosci. 2004 Jun;16(5):839–847. DOI: 10.1162/089892904970780. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1266050/pdf/nihms5373.pdf
Keywords: qualia, quale, conscious awareness, conscious experience, consciousness, phenomenal characteristics, experiential characteristics