Medical experts have known for a long time that caffeine affects cognition: think of how awake, aware, and ready to go you feel after your first (or second) cup of coffee in the morning. By stimulating your brain and preventing adenosine buildup, it can provide some alertness, but you may find it causes more anxiety and jitteriness if you aren’t a regular caffeine user. 55 Even compared to prescription stimulants, caffeine repeatedly appears in studies to improve your attention span. 56 a b Nagel, Thomas (Oct 1974). "What Is It Like to Be a Bat?". The Philosophical Review. 83 (4): 435–450. doi: 10.2307/2183914. JSTOR 2183914. Attention. Qualia and attention are closely linked. You need attention to fulfill criterion number two; to choose. A study of circuits involved in attention, therefore, will shed much light on the riddle of qualia. [41]

Dennett argues that the misleading aspect of the story is that Mary is supposed to not merely be knowledgeable about color but to actually know all the physical facts about it, which would be a knowledge so deep that it exceeds what can be imagined, and twists our intuitions. If Mary really does know everything physical there is to know about the experience of color, then this effectively grants her almost omniscient powers of knowledge. Using this, she will be able to deduce her own reaction, and figure out exactly what the experience of seeing red will feel like. [45] :15–16 Theobromine, one of the most prominent compounds in cocoa, shares a chemical class with caffeine. Since they’re relatively similar substances, scientists have started investigating if theobromine has the same nootropic effects as caffeine. One study from 2019 suggests that theobromine works more slowly and provides less of an intense reaction than caffeine, but it might have neuroprotective effects by reducing the amount of beta-amyloid peptides (which scientists think trigger Alzheimer’s disease). 48 Alter, Torin. "The Knowledge Argument". A Field Guide to the Philosophy of Mind. University of Rome. Archived from the original on 2012-12-03 . Retrieved 2007-01-22. a b c Levine, J. (1999). "Conceivability, Identity, and the Explanatory Gap". In Hameroff, Stuart R.; Kaszniak, Alfred W.; Chalmers, David John (eds.). Toward a science of consciousness. Complex adaptive systems. Cambridge (Mass.): MIT press. pp.3–12. ISBN 978-0-262-58181-3. Archived from the original on 2010-08-31 . Retrieved 2023-07-19.

a b c Damasio, Antonio R. (2000). The feeling of what happens: body and emotion in the making of consciousness. A Harvest book (1ed.). San Diego, CA: Harcourt. ISBN 978-0-15-601075-7. Edelman, Gerald Maurice (1993). Bright air, brilliant fire: on the matter of the mind. New York: BasicBooks. p.115. ISBN 978-0-465-00764-6. Kafeshani, M., Feizi, A., Esmaillzadeh, A., Keshteli, A. H., Afshar, H., Roohafza, H., & Adibi, P. (2019). Higher vitamin B6 intake is associated with lower depression and anxiety risk in women but not in men: A large cross-sectional study. Vitamin and Nutrition Research, 90(5-6), 484-492. https://econtent.hogrefe.com/doi/10.1024/0300-9831/a000589 This may mean that there would be asymmetric outcomes between altering the mechanism of perception of qualia and altering the memory of that qualia. If the diabolical neurosurgery altered the immediate perception of qualia, the inversion might not be noticed directly, since the brain zones which re-process the memories would invert the remembered qualia. On the other hand, alteration of the qualia memories themselves would be processed without inversion, and thus you would perceive them as an inversion. Thus, you might know immediately if memory of your qualia had been altered, but might not know if immediate qualia were inverted or whether the diabolical neurosurgeons had done a sham procedure. [43] If there are any minor stressors induced by too high of a dose (called the hormetic response, like getting a sunburn from being in the sun for too long)

Ismail, N., Kureishy, N., Church, S. J., Scholefield, M., Unwin, R. D., Xu, J., Patassini, S., & Cooper, G. J. (2020). Vitamin B5 (d-pantothenic acid) localizes in myelinated structures of the rat brain: Potential role for cerebral vitamin B5 stores in local myelin homeostasis. Biochemical and Biophysical Research Communications, 522(1), 220-225. https://www.sciencedirect.com/science/article/pii/S0006291X19321722 David Chalmers formulated the hard problem of consciousness, which raised the issue of qualia to a new level of importance and acceptance in the field of the philosophy of mind. [28] In 1995 Chalmers argued for what he called "the principle of organizational invariance": if a system such as one of appropriately configured computer hardware reproduces the functional organization of the brain, it will also reproduce the qualia associated with the brain. [29] E. J. Lowe [ edit ] The idea that an inverted spectrum would be undetectable in practice is also open to criticism on more scientific grounds, by C. L. Hardin, among others. [15] [16] As Alex Byrne puts it: Various authors (19 March 2007). Chalmers, David (ed.). "Online collection of papers on qualia". Archived from the original on 2007-03-19. Artificial intelligence researcher Marvin Minsky thinks the problems posed by qualia are essentially issues of complexity, or rather of mistaking complexity for simplicity.

Kripke, Saul A. (1977), "Naming and Necessity", in Davidson, Donald; Harman, Gilbert (eds.), Semantics of Natural Language, Synthese library (2. ed., 3. printed.), Dordrecht: Reidel, pp.253–355, doi: 10.1007/978-94-010-2557-7_9, ISBN 978-90-277-0310-1 , retrieved 2023-07-18 Secades, J. J. (2019). Citicoline in the treatment of cognitive impairment. Journal of Neurology & Experimental Neuroscience, 5(1), 14-26. https://jneuroscience.com/jnen/articles/v5n1/jnen-047-julio-j-secades.pdf Many definitions of qualia have been proposed. One of the simpler, broader definitions is: "The 'what it is like' character of mental states. The way it feels to have mental states such as pain, seeing red, smelling a rose, etc." [3] ALC is a naturally-occurring form of carnitine, an amino acid that assists in brain, liver, and kidney functioning. Carnitine is mostly found in red meat and is thought to primarily improve cellular energy metabolism in the brain. It also appears to have some antioxidant and anti-inflammatory properties, and a few studies have found it can improve recovery outcomes after a stroke. 73

Dennett uses this example as an attempt to show us that Mary's all-encompassing physical knowledge makes her own internal states as transparent as those of a robot or computer, and it is as straightforward for her to figure out exactly how it feels to see red. [45] :16–17 Ungerleider, L. G. (1995-11-03). "Functional brain imaging studies of cortical mechanisms for memory". Science. 270 (5237): 769–775. Bibcode: 1995Sci...270..769U. doi: 10.1126/science.270.5237.769. ISSN 0036-8075. PMID 7481764. S2CID 37665998. In his book On Human Nature, [53] Scruton poses a potential line of criticism to this, which is that while Wittgenstein's private language argument does disprove the concept of reference to qualia, or the idea that we can talk, even to ourselves, of their nature; it does not disprove their existence altogether. Scruton believes that this is a valid criticism, and this is why he stops short of actually saying that qualia do not exist, and instead merely suggests that we should abandon the concept. However, he quotes Wittgenstein in response: "Whereof one cannot speak, thereof one must be silent." [53] See also [ edit ] Barrou, Z., Charru, P., & Lidy, C. (1997). Dehydroepiandrosterone (DHEA) and aging. Archives of Gerontology and Geriatrics, 24(3), 233-241. https://www.sciencedirect.com/science/article/abs/pii/S0167494396007613Nida-Rümelin, Martine (2021). "Qualia: The knowledge argument". Stanford Encyclopedia of Philosophy. Stanford University. William Robinson (no relation) takes a similar view in his book, Understanding Phenomenal Consciousness. [36] He is unusual as a dualist in calling for research programs that investigate the relation of qualia to the brain. The problem is so stubborn, he says, that too many philosophers would prefer "to explain it away", but he would rather have it explained and does not see why the effort should not be made. [ citation needed] However, he does not expect a straightforward scientific reduction of phenomenal experience to neural architecture; he regards this as a forlorn hope. The qualitative event realism that Robinson espouses sees phenomenal consciousness as non-material events that are caused by brain events but not identical to them. [ citation needed]