Qualia are the subjective, conscious experiences that are unique to each individual. This definition of qualia is typically a philosophica...
Qualia are the subjective, conscious experiences that are unique to each individual. This definition of qualia is typically a philosophical approach to the phenomenon, and requires explanation through concrete examples.
A classic example of a qualia is the experience of color vision. Color is a physically nonexistent property of the electromagnetic radiation of light. The human eye is sensitive to a well-defined, rather narrow range of the broad electromagnetic spectrum. The visible light spectrum is sensed by three types of receptors in the eye that are sensitive to different, overlapping parts of the visual spectrum. The sensed visual information is then transmitted as neural activity to the brain for processing.
When we see the entire visible light spectrum sorted by wavelength, for example, when the rainbow appears naturally, the visible light spectrum appears to us as a well-defined color gradient from red through yellow to violet. However, these colors are information that actually does not belong to the visible light spectrum, color as a corresponding property of electromagnetic waves is not part of electromagnetic radiation, somehow it is produced by the nervous system of the brain by itself, for itself.
This phenomenon of artificially added information can be clearly observed in the case of the color brown. The visual information of brown obviously exists for us, but it is not a natural color in the meaning that brown is not part of the visible light spectrum, not part of the colors of the rainbow.
The brain also sees colors other than the natural colors of the rainbow, such as white and black. These non-natural colors, which are not part of the continuous spectrum of visible light, are produced when the brain perceives certain wavelengths of light together. The visualization of colors, colors as qualia, information that does not exist in reality, is created by the brain in association with the spectrum of light perceived by the eyes.
Using color vision as an example, a more specific, less philosophical definition of qualia can be formulated that more precisely defines its real nature: qualia is the perception of a property that does not actually exist in reality, which appears in the nervous system about the world through the information perceived by the senses.
How does the neural process that represents the qualia of color vision work? How does the physical interpretation of qualia emerge in the brain?
Color vision is obviously an evolutionary advantage, which is a phenomenon related to seeing surfaces. A nervous system that is able to somehow distinguish a particular spectrum of light - in this case by perceiving it as a color - reflected from a surface from other surfaces that reflect a different spectrum of light could, for example, effectively detect ripe fruit on a tree, which would be much more difficult without this ability.
Color vision is an evolutionary invention and therefore a genetically determined ability. Since it is genetically determined, it can also be said that within biological species, the same perceived information, in this case that does not actually exist, the information created and added by the nervous system to the information sensed, the subjective qualia, normally must produce similar experiences in individual members of the same species. The color red is certainly the same experience for all humans with normally developed nervous systems, it is not a learned but an inherited trait.
In searching for the neural origin of color experience, it is worth noting that in some cases color experience is not solely related to the neural mechanism of vision. For example, in some people, the perception of sounds or smells can also trigger the perception of color, supporting the idea that the neural mechanism of color experience is primarily visual, but it can also act universally, adding this unique information caused by specific neural activity to the perceived stimuli.
The genetic determination of color and the universality of its function suggest that people who are blind from birth should be able to experience color if the neural mechanisms that generate color vision in the brain are intact.
It can therefore be logically concluded that the experience of color is a specific neural response to specific sensations, a neural activity that does not need to be associated only with a philosophical concept that is physically difficult to grasp.
Color vision must be associated with specific brain areas, a neural activity of that area. It is an interesting observation that color vision as a neural activity is also somehow related to face recognition, since the most common disorder seen alongside cerebral achromatopsia is prosopagnosia, the inability to recognize or recall faces. This association supports the link between color vision and neural function related to surface perception.
Why is it the experience of a particular color that we perceive? Why is the sight of the color red seen?
Color vision is an evolutionary ability that certainly evolved in several steps. The first evolutionary step towards this ability in the animal world was the sensation of light, therefore the two basic evolutionary colors must be white and black and their appearing shades. In the process of evolutionary development, of adaptation of species to their environment, a specific surface recognized by vision, important for sustaining life, gives an evolutionary advantage to the survival of the individual, the recognition of this surface creates a positive evolutionary feedback by selection. The unique visual separation of these surfaces can be achieved by the nervous system through an artificially generated property associated with the specific spectrum of light reflected by these surfaces and recorded by the eye, which creates a sensation perceived by the brain as color, and whose generated property is also accessible to the visual nervous system. In the course of evolution, selection for survival must have led to the appearance of new colors in the visual neural processes of different species.
Consequently, there may be colors that do not exist for humans, that are not specified by the human nervous system, that have no evolutionary advantage for humans to recognize. However, other species of animals can certainly see other colors. For example, there are animal species that can see ultraviolet or infrared light. These animals might see these spectra of light as seeing colors. These colors do not exist for human beings. During the evolutionary development of human perception, a new color could possibly emerge in the spectrum of light that we see, for a particular combination of wavelengths, if there is an evolutionary advantage to recognizing a surface with a particular spectral combination. However, natural evolution in the case of humans is already limited, so the emergence of new colors in the natural evolutionary development of humans is unlikely, but unique genetic mutations could possibly create such a phenomenon.
The appearance of color is certainly a created property discovered through evolution. But why is it the color we see it as it is? Why is the color red the way we see it?
The purposeless mechanism of evolution corresponds to evolutionary changes that are the result of random genetic mutations that, if they produce a useful trait, are passed on. Color vision confers an evolutionary advantage, but seeing a particular spectrum of light associated with a particular surface does not result in a particular genetic mutation, so why the color we see is the color we see must be the result of purposeless random genetic changes, an undefinable eventuality. The only significant aspect of the corresponding genetic variation that creates color perception is that colors must be clearly distinguishable from each other during perception.
In conclusion, color perception is not a philosophical concept, but must be a specific neural mechanism, a specific neural activity that responds specifically to a particular wavelength or combination of wavelengths of the visual light spectrum received by the eyes, and generates a unique neural activity related only to these spectra, adding a new property to the information perceived during vision, which becomes available and accessible to the visual neural system and other brain areas. The brain area responsible for visual perception specific to color generation is the neural area that is active when a particular color is imagined with the eyes closed (and when we are able to do it, because the color vision has strong connection to the active visual neural activity).
This must be the neural process of how color perception is created, but how does the experience of color appear in consciousness?
This question is not specifically a question about color perception, but a phenomenon related to the functioning of consciousness in general. The two processes must be strictly distinguished. In species where consciousness is certainly not present, color vision might be available as information artificially added to visual stimuli by the nervous system, for example in bees. The higher level of color vision, the experience of color in consciousness, certainly operates by a similar mechanism as the association of any other sense associated with consciousness. Thus, the representation of color experience in consciousness does not need to be investigated in a specific way.
Based on the discussion of the emergence and functioning of consciousness in thoughts, the phenomenon of consciousness can be defined as the activity of different neural areas of the brain forming a global neural resonance that is self-sustaining and self-excitatory by internal neural feedback mechanisms which has a back-exciting effect on the activity of the neural circuits that generate it. The perception of color associated with vision can become part of this global neural activity, and thus color vision, like all other neural activity associated with this global activity, can appear in consciousness.
Similar to color vision, the experience of other qualia-like senses, such as smell, taste, touch, and hearing, could have been formed by similar evolution-based neural mechanisms through artificially added information created by the brain.
The phenomenon of qualia is not necessarily a philosophical concept, it is obviously linked to specific physiological mechanisms and can necessarily be explained in terms of physiological processes. This thought was an attempt at that explanation.
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