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Cognitive Science: An Introduction/What Consciousness Is

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Defining Consciousness

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In English we use the word "conscious" to mean several things. The simplest one describes the difference between being asleep and awake. We say that sleeping people are "unconscious" and awake people are "conscious." The other meaning refers to our general awareness of things. So we can be unconscious of our biases, or that a bird flew by, perhaps because our attention was elsewhere. Indeed, we have a form of consciousness when we dream, in that we are consciously aware of what's happening in the dream. Similarly, even people in comas, who we might normally classify as "unconscious," go through normal sleep and wake cycles, as indicated in brain scans.

We also use the word "conscious" to describe certain kinds of entities: humans are conscious creatures, but worms are (probably) not. When we ask whether a particular species (or other kind of entity, such as a running computer program) is conscious, we mean to ask whether it can feel any conscious states at all.

So we have at least three definitions of consciousness that get used on cognitive science:

  1. an agent is considered conscious if it can have some mental states that it is aware of
  2. an agent that can experience conscious states is considered conscious if it is not asleep
  3. an agent can be conscious of some mental states but not others in its own mind

The Function of Consciousness

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If an unconscious process can do everything a conscious one can do (and we don't know if this is the case), then what is consciousness for? This question is hard to answer theoretically, for any conceivable agent, but is a little easier to tackle in human beings. But note that just because human beings use consciousness to do this or that does not mean that it would be necessary for any conceivable agent to require consciousness to do the same thing--creatures with different mental architectures might do it differently--or maybe that's impossible. We just don't know.

Conscious vs Unconscious

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There are things we can be conscious of if we direct our attention to them, and things we cannot be conscious of. There is probably nothing we are *always* conscious of, as thoughts, plans, emotions, and even pain can be unconscious.

Conscious thought seems to allow certain kinds of thinking to take place. Because we can be conscious of some things and not others, we can think of it as a resource, or a rare commodity in the brain that the unconscious processes compete for access to.

Conscious thinking can be contrasted with other kinds of thinking, which for purposes of this chapter we will call "unconscious" or "implicit." There are a great many unconscious processes in the mind, running all the time. Consciousness feels like the most important part of our mind. Interestingly, consciously determined behavior is relatively rare. Estimates suggest that 95% of our behavior is determined by unconscious processes.[1] The conscious processing relies on the unconscious processes and their outputs, but the reverse is not true--the unconscious processes can work just fine without consciousness.[2] So even conscious creatures (such as human beings), when awake (not unconscious) are only conscious of some of their mental states.

It doesn't seem as though language would have much to do with consciousness--we feel that we are conscious of a roller coaster ride without having to put words to it. However, Helen Keller, who was born blind and deaf, said "Before my teacher came to me, I did not know that I am. I lived in a world that was a no-world... When I learned the meaning of `I' and `me' and found that I was something, I began to think. Then consciousness first existed for me." [3] Now, we don't know what Keller meant, exactly, by thinking and consciousness, but her report is intriguing. What does it mean for animals, who have no language?

The Neuroscience of Consciousness

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Consciousness is defined as the state of being aware or awake; of noticing the existence of something [4]. In neuroscience, the definition of consciousness is continually shifting as scientists advance their understand of the phenomena. A prerequisite to the definition of consciousness is the presence of experience [5].

It is unknown where in the brain consciousness happens. Some suggest that it doesn't happen in any particular place, but consciousness is merely great activation of any part of the brain, or the central executive's focus on some or other functioning in the brain.[6]

Cognitive science has divided conscious experience into two major aspects: local states and global states. Local states of consciousness involve experiences from perception, such as visual imagery, bodily sensations, affective experiences, and present thoughts. This is also referred to as “conscious content,” as determined by the object’s noticeable features. Alternatively, global states of consciousness are related to broad cognitive, behavioral and physiological features such as alertness, wakefulness, minimally conscious state, or dreaming [7].

Source of consciousness

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At present, the neural source of consciousness remains unclear. However, Harvard scientists are moving closer to finding its biological sources. Notably, an important connection was found in the region of the brainstem involved in arousal [8]. Research into awareness has been correlated with the outer cortex of the brain. However, identifying precise regions with accuracy remains challenging. So far, neuroscientists have identified specific region of the brainstem related to arousal, and two cortex regions that appear to facilitate conscious states [9]. In one study, 36 patients with brainstem lesions were analyzed, 12 of whom were comatose, while the other 14 subjects were conscious. Using fMRI, patient’s brainstems were mapped to better understand why some remained conscious after they sustained injuries, while others languished in comas. The area of the brainstem found to be significantly associated with a comatose state is the rostral dorsolateral pontine tegmentum. Of the 12 patients with damaged brainstems, 10 of these were comatose. Conversely, of the 24 conscious patients, only 1 had damage to this area. The researchers found two additional areas in the cortex correlated with regulating conscious states, the left ventral anterior insula and the pregenual anterior cingulate cortex. While these results corresponded with previous studies on arousal, it was the first time that conscious states were correlated with the brainstem.

Probing consciousness in the brain stem

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While assessing consciousness in unresponsive patients, the principle approach in biomedical models is the analysis of non-reflexive, assumedly intentional behavior. These include testing patients’ reactions to sound and touch, and in some cases nocioceptive stimuli that stimulates pain in nerve cells [10]. Unstandardized assessments that include simple verbal commands such as “stick out your tongue” or “show me four fingers” have error rates as high as 40%. An often used consciousness-assessment measure is the Coma Recovery Scale-Revised (CRS-R). The scale measures auditory, visual, motor, communication and arousal responses and orders the data hierarchically to yield an overall score. Depending on the absence or presence of behavioral metrics, scores can range between 0-23 [11]. These test have to be repeated and the scores aggregated, as patients’ consciousness often fluctuates throughout. Importantly, the measure of arousal refers to the correlation between sensory stimulation and fiber activation in the reticular activating system (RAS). The RAS is a network of neurons in the brain stem particularly involved in the regulation of arousal, alertness and the sleep-wake cycles [12].

Biomarkers correlated to consciousness

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Biomarkers associated with levels of consciousness are neurophysiological correlates such as brain metabolism, blood flow, and electrical activity. Research indicates that when brain metabolism drops below normal, reports of consciousness also declines. A study of brain metabolism, called position emission tomography (PET), revealed a greater metabolism rate in those who had unresponsive wakefulness syndrome [13]. This syndrome holds no clinical signs of awareness or minimal consciousness to commands while having their eyes open[14].

An EEG report can be analyzed by breaking down spectral patterns and quantifying their complexity and connectivity. The EEG’s complexity can be assessed by entropy measures [15]. Entropy refers to the degree of order, disorder, or randomness in a system. A 2016 study identified correlations between entropy measures and level of consciousness in subjects.

One method assesses the neurocorrelates of consciousness by using transcranial magnetic stimulus (TMS) to activate regions of the parietal cortex [16]. Another EEG measure is called the perturbational complexity index, and allows doctors to estimate the patient’s level of consciousness with better accuracy throughout various states of sleep, anesthesia, and injury [17]. Another sleep study [18] roused subjects during the night using an EEG. It was reported that approximately 30% of the time, the participants who were jolted from their sleep did not experience anything prior to waking up. The participants without memory of conscious experiences tended to have lower frequency activity in the posterior cortical prior to being awakened. Participants who remembered dreaming showed higher frequency activity throughout the night. The researcher suggested that monitoring the “hot zone” in the posterior cortical region during sleep could predict a person’s dreaming and hence conscious states.

Pattern recognition

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A recent study analyzed the brain activity of 125 people while they slept or rested [19]. Forty-seven healthy participants had unresponsive wakefulness syndrome. Scientists found two different patterns of activity in the brain. The first was a complex pattern that did not follow normal anatomical brain pathways. The second pattern was simple and constrained to standard brain anatomy. Participants who were fully conscious exhibited the complex pattern for a longer time, while those with unresponsive wakefulness syndrome displayed the simpler pattern. Those with minimal consciousness exhibited both patterns interchangeably. Also, when healthy patients were anesthetized, they displayed the simple pattern of brain activity indicates a further relationship with consciousness [20].

Consciousness and the thalamus

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Research has implicated the thalamus as playing a nm important role in consciousness. A recent experiment employed ultrasound to stimulate the thalamus in people with brain damage [21]. The initial test was conducted on a comatose man who had been injured in a vehicle accident. After three days of ultrasound stimulation, he became able to understand language, respond to commands, and make head intentional gestures. After five days he began attempting to walk. This treatment has since been used in persistent coma patients with encouraging results. However, a few weeks after the thalamus was stimulated, many patients reverted to their original state. While evidence supports the view that consciousness is affected by changes in neurological brain states, no single mechanism has yet been found. To date, a full picture of the neurological underpinnings of consciousness remain elusive[22].

The Hard Problem of Consciousness

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We discussed above what consciousness seems to be for in human beings, but, hard as it is to study, it's considered "the easy problem" by philosophers. The "hard problem" is knowing whether and why a particular mental process needs consciousness or not. The philosopher David Chalmers introduced the idea of a "zombie" to help us think about it.

Mary the Colourblind Scientist: Thought Experiment and Responses

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Mary the colorblind scientist is a philosophical thought experiment that was proposed by Frank Cameron Jackson in 1986, to allow the knowledge argument for qualia to gain traction and make points against physicalism. There are three essential terms mentioned above: knowledge argument, qualia, and physicalism that we need to understand. The knowledge argument states that conscious experiences involve non-physical properties. Having an understanding of a conscious being’s physical knowledge doesn’t allow you to acquire insights about how it feels to have certain sensory experiences [23]. Qualia refers to introspectively accessible phenomena of one’s mental experiences. For example the smell of skunk or seeing bright purple, the individual is subjected to a mental state with a unique subjective character [24]. Qualia are often subjective as one person’s experience may differ from another person’s. Physicalism is described by Frank Jackson in terms of information more than anything else, stating that physical, chemical, and biological sciences provide information about us and the world [25] whereas other sources treat it as the nature of the actual world which encompasses all there is in the universe, where all comply to being physical [26]. However, physicalists do believe that the physical (e.g. bruising, crying, etc) and mental (e.g. jealous, love, desire) is one but as per dualism, they are two separate entities. The arguments being made against Physicalism are to address that there are things that are inherently not physical and not everything can be explained in physical terms. These terms will be further illustrated using Mary the Colourblind Scientist. The thought experiment entails Mary, a brilliant scientist who is forced to view the world in only black and white, to the point the room she is in is also black and white and so is the television monitor that she interacts with. Her specialization is neurophysiology of vision in which she has been able to gather all the physical information there is to know. But when Mary is released from her black and white environment and experiences color for the first time the question asked is, “Will she learn anything or not?” [25]. As we progress we shall answer that very question posed by Frank Jackson, see how it contrasts with other responses, and go on to understand some of the criticisms associated with this approach taken and see how Frank Jackson’s own belief in his work evolves over time.

What was the physical information that was being acquired?

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Knowing that Mary is well versed with all physical facts about color but has never seen color, so when she does see color what does she learn? We, humans, sense our world through sight, sound, touch, smell, and taste each giving us some information (sensations and feelings) about the thing we are trying to determine [27]. The information Mary knows is the anatomy of the eye, the different wavelengths of light, how light interacts with the rods and cones for us to perceive color. This doesn’t tell Mary what it is like to experience color. The knowledge deduced from this experience doesn’t come from a third person as its interpretation can be subjective [27]. The subjective nature is deemed by associations made from an experience that one has or has had, which they are able to recall from memory. So when Mary sees red as compared to someone else seeing the same red, the experience will be quite different. The ability to imagine something comes from firsthand (or personal) memories of the color experience [28].

If physicalism is true then all things are physical facts which in term means that there are no facts for non-physical things, so the only facts you could know are physical facts. But Jackson argues that there are facts for non-physical things making physicalism false. The challenge comes from being able to distinguish between physical and non-physical (phenomenal).

Criticism against the Knowledge Argument

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Physicalists state that Mary learns nothing new when she leaves the black and white room, the nuance being she learns no new facts. The experience she undertakes is being provided the same old facts in a different representation [29]. This was called the New Fact Thesis.

However, as per the Ability Analysis posed by Laurence Nemirow and David Lewis, it states that having an experience is not considering factual knowledge, it is the ability to remember and recognize something. They want to answer “what a certain kind of experience is like” [29] and it stresses the point that possessing the ability to imagine an experience is vital to know what an experience is like. Mary gains the ability to see color and this experience will be part of her memory allowing her to recollect this thought at a later stage, even when the stimulus is not around she can imagine it. However, the counter argument posed to counter this approach is when a certain individual was found who doesn’t have the imagine things, is still able to recognize a red tomato even if he can’t imagine it during its absence showcased how imagining something might not be important [29]. The Ability analysis focuses on the elements of imagining, recognizing, and remembering experiences.

Acquaintance analysis devised by Earl Conee suggests that upon release Mary learns “what color experiences are like but denies knowing color experiences are like is factual knowledge” this states that Mary does acquire new knowledge but doesn’t state what the nature of knowledge was which was acquired [29]. This analysis used the premise of knowledge by acquaintance which has to do with being acquainted with an object, having a direct cognitive relation to the object be established [30]. This is like reading about something as compared to seeing something in person that can evoke different emotions. However, watching someone through a tv screen may fill in the gaps of reading. Mary only learns about what color experiences are like after she leaves the room which means she acquired acquaintance knowledge that has no factual insights but more so an experience.

Note that the above two analyses speak of experiences where the physicalists approach the topic without taking the sensations of that experience into consideration. The Old fact/ new guise analysis done by Paul Churchland and other individuals take the approach that Mary seems to gain knowledge but in reality, the facts she already knew are being represented in a new way [29]. Marry simply acquires knowledge in a new way that was not available to her in the past. Now out of the various analysis which one resonated with Jackson the most?

Why did Frank Jackson change his mind

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Frank Jackson in 1998 is no more in favor of the Knowledge Argument. He illustrates it by stating seeing red and feeling pain has an impact on us, this impact from the experience is translated into a memory that allows us to reside the knowledge of feeling pain or seeing red but people can experience a false memory [31]. A false memory is merely remembering something that has never happened and can happen to either fill in the gap or be completely fabricated [32]. “The redness of our reds can deduced in principle from enough about the physical nature of our world despite the manifest appearance to the contrary” [31], and what this statement is illuding towards is with the sufficient physical knowledge Mary may have some representation of red and her red might not be the same as someone else’s red.

In 2003, Frank Jackson further adds to his support to physicalism by stating his belief in the scientific approach as to intuition and states that from an intuitive perspective she can deduce what it’s like to see red [33]. He reflects on the gaps in Mary’s knowledge despite assuming she is all-knowing when it comes to the physical nature of our world, if she has that information why does a gap exist? Initially one would think it is impossible to account for experiencing the sensation of seeing color but that knee-jerk reaction is more of an intuitive constraint. The experience generated by “What it is like” can be translated to all properties of seeing red, and if one knew all properties that makes it possible [33]. Jackson brings the idea of representationalism which is merely our mind perceiving mental images of objects in the real world, but not the very object itself [34]. Recall how this relates to his early criticism pertaining to false memories has the potential to see things that she has never encountered, these representations are subjective and built upon her sensory information acquired and knowledge from her memories. Notice how elements of representationalism revolve around being able to recognize, imagine, and remembering experiences, from where Jackson was able to draw the connection between the ability hypothesis, and this very path led Jackson to put his faith in the Ability Analysis [33]. So this leads him to believe that when Mary leaves the black and white room she learns nothing new. His attempt to rule out the aspect of phenomenal state (has to do with the overall experience more than just the physical), to more of a representational state.

References

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  1. ↑ Bargh, J.A. & Chartrand, T.L. (1999). The unbearable automaticity of being. American Psychologist, 54: 462--479.
  2. ↑ Goodwyn, E.D. (2012). The neurobiology of the gods: How brain physiology shapes the recurrent imagery of myth and dreams. New York: Routledge., kindle location 622.
  3. ↑ Jabr, F. (2014). Speak for yourself. Scientific American mind. January/February, 46—51.
  4. ↑ Consciousness. (2020). Cambridge Dictionary Online. https://dictionary.cambridge.org/dictionary/english/consciousness
  5. ↑ Velmans, M. (2009). How to define consciousness – and how not to define consciousness. J. Conscious. Stud. 16, 139–156.
  6. ↑ Levitin, D. J. (2014). The Organized Mind: Thinking Straight in the Age of Information Overload. New York: Penguin. Page 45.
  7. ↑ Bayne, T., Hohwy, J., & Owen, A. M. (2016). Are There Levels of Consciousness? Trends in Cognitive Sciences, 20(6), 405–413. https://doi.org/10.1016/j.tics.2016.03.009
  8. ↑ Parvizi, J., & Damasio, A. (2001). Consciousness and the brainstem. Cognition. https://doi.org/10.1016/S0010-0277(00)00127-X
  9. ↑ Fischer, D., Boes, A., Demertzi, A., Evrard, H., Laureys, S., Edlow, B.., & Geerling, J. (2016). A human brain network derived from coma-causing brainstem lesions. Neurology,87(23), 2427–2434. https://doi.org/10.1212/WNL.0000000000003404
  10. ↑ Giacino, J. T., Katz, D. I., Schiff, N. D., Whyte, J., Ashman, E. J., Armstrong, M. J. (2018). Practice guideline update recommendations summary: Disorders of consciousness. Neurology,91(10), 450–460.
  11. ↑ Giacino, J. T., Ashwal, S., Childs, N., Cranford, R., Jennett, B., Katz, D. I., Zasler, N. D. (2002). The minimally conscious state. Neurology, 58(3), 349–353.
  12. ↑ Garcia-Rill, E. (2009). Reticular Activating System. In Encyclopedia of Neuroscience. https://doi.org/10.1016/B978-008045046-9.01767-8
  13. ↑ Stender, J., Gosseries, O., Bruno, M., Charland-Verville, V., Demertzi, A., Laureys, S. (2014). Diagnostic precision of PET imaging and functional MRI in disorders of consciousness: a clinical validation study. The Lancet, 384(9942), 514–522.
  14. ↑ Laureys, S., Celesia, G.G., Cohadon, F. (2010). Unresponsive wakefulness syndrome: a new name for the vegetative state or apallic syndrome. BMC Med 8, 68. doi:10.1186/1741-7015-8-68
  15. ↑ Claassen, J., Velazquez, A., Meyers, E., Witsch, J., Falo, M.C., Park, Agarwal, S., Schmidt, J., Schiff, N.D., Naccache, L., Connolly, E. (2016). Bedside quantitative electroencephalography improves assessment of consciousness in comatose subarachnoid hemorrhage patients. Annals of Neurology. https://doi.org/10.1002/ana.24752
  16. ↑ Casali, A. G., Gosseries, O., Rosanova, M., Boly, M., Sarasso, S., Massimini, M. (2013). A theoretically based index of consciousness independent of sensory processing and behavior. Science Translational Medicine. https://doi.org/10.1126/scitranslmed.3006294
  17. ↑ Casarotto, S., Comanducci, A., Rosanova, M., M., Napolitani, M., Massimini, M. (2016). Stratification of unresponsive patients by an independently validated index of brain complexity. Annals of Neurology. https://doi.org/10.1002/ana.24779
  18. ↑ Behrmann, M., Geng, J. J., & Shomstein, S. (2004). Parietal cortex and attention. Current Opinion in Neurobiology. https://doi.org/10.1016/j.conb.2004.03.012
  19. ↑ Demertzi, A., Tagliazucchi, E., Dehaene, S., Deco, G., Barttfeld, P., J. D. (2019). Human consciousness is supported by dynamic complex patterns of brain signal coordination. Science Advances, 5(2). https://doi.org/10.1126/sciadv.aat7603
  20. ↑ Baars, B., & Gage, N. (2010) Cognition, Brain and Consciousness. Introduction to Cognitive Neuroscience. (2011). South African Journal of Occupational Therapy.
  21. ↑ Monti, M. M., Schnakers, C., Korb, A. S., Bystritsky, A., & Vespa, P. M. (2016, November). Non-Invasive Ultrasonic Thalamic Stimulation in Disorders of Consciousness after Severe Brain Injury: A First-in-Man Report. Brain Stimulation. United States.
  22. ↑ Thomas, Joseph. (2019). Current Status of Consciousness Research from the Neuroscience Perspective. https://doi.org/10.1016/j.conb.2004.03.012
  23. ↑ Nida-Rümelin, M., & O Conaill, D. (2021). Qualia: The Knowledge Argument. In The Stanford Encyclopedia of Philosophy. Metaphysics Research Lab, Stanford University.
  24. ↑ Tye, M. (2021). Qualia. In The Stanford Encyclopedia of Philosophy. Metaphysics Research Lab, Stanford University.
  25. ↑ a b Jackson, F. (1982). Epiphenomenal Qualia. The Philosophical Quarterly, 32(127), 127-136.
  26. ↑ Stoljar, D. (2021). Physicalism. In The Stanford Encyclopedia of Philosophy. Metaphysics Research Lab, Stanford University.
  27. ↑ a b Stone, V. (2010). If we accept that Mary, the color scientist, gains new knowledge when she sees the color red for the first time, must this lead us to a non-physicalist theory of consciousness?. Psyche, 16(1).
  28. ↑ Alter, T., & Walter, S. (2007). Phenomenal Concepts and Phenomenal Knowledge: New Essays on Consciousness and Physicalism. : Oxford University Press. Retrieved 9 Oct. 2021
  29. ↑ a b c d e Alter, T. (1998). A Limited Defense of the Knowledge Argument. Philosophical Studies: An International Journal for Philosophy in the Analytic Tradition, 90(1), 35–56.
  30. ↑ Hasan, A., & Fumerton, R. (2020). Knowledge by Acquaintance vs. Description. In The Stanford Encyclopedia of Philosophy. Metaphysics Research Lab, Stanford University.
  31. ↑ a b Jackson, F. (1998). Mind, method, and conditionals: Selected essays. London: Routledge.
  32. ↑ VandenBos, G. R., & American Psychological Association. (2007). APA dictionary of psychology. Washington, DC: American Psychological Association.
  33. ↑ a b c Jackson, F. (2003). Mind and Illusion, in Minds and Persons: Royal Institute of Philosophy Supplement 53, ed. by Anthony O’Hear, Cambridge: Cambridge University Press, 251-271.
  34. ↑ Britannica, T. Editors of Encyclopaedia (2016). Representationism. Encyclopedia Britannica.
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