(Edit note: From the comments I’ve received, it seems that the paragraph beginning with “On the other hand” was not clear enough and can be misunderstood, so I add some clarifying sentences at the end of the paragraph – they are the italic sentences after (5).)
Q (the original question): Which aspects of consciousness are philosophically most important?
A: In philosophy, the most important issue about consciousness seems to be about its phenomenal part – the part that consciousness exhibits what it is like to see the red color, to hear the music, to feel pain, to be happy, to recall a past event, to …, and, most of all, to be conscious. (1-4)
The really hard problem of consciousness is the problem of experience. When we think and perceive, there is a whir of information processing, but there is also a subjective aspect. As Nagel (1974) has put it, there is something it is like to be a conscious organism. This subjective aspect is experience. When we see, for example, we experience visual sensations: the felt quality of redness, the experience of dark and light, the quality of depth in a visual field. Other experiences go along with perception in different modalities: the sound of a clarinet, the smell of mothballs. …
… It is widely agreed that experience arises from a physical basis, but we have no good explanation of why and how it so arises. Why should physical processing give rise to a rich inner life at all? It seems objectively unreasonable that it should, and yet it does.
If any problem qualifies as the problem of consciousness, it is this one. In this central sense of "consciousness", an organism is conscious if there is something it is like to be that organism, and a mental state is conscious if there is something it is like to be in that state. Sometimes terms such as "phenomenal consciousness" and "qualia" are also used here … Chalmers 1995 (1)
Regarding the other parts, the integrative/command parts of consciousness – detecting stimuli; directing and maintaining attention to the stimuli; analyzing and binding information from the stimuli; distributing, storing, and retrieving information (the memory functions you queried about); creating awareness of self and non-self; planning and making decisions; commanding motor, verbal, and other responses; etc. – AI (computers, robots, etc.) can have these parts of consciousness in its central processing units (CPUs) as we do, and it can be even be better at these tasks than we are. So, none of these consciousness parts differentiates us from AI. (5)
On the other hand, it is definite that present-day computers and robots do not and cannot have phenomenal consciousness as we do. This is because phenomenal consciousness is an additional function and has additional information. So, computers and robots need a specific, dedicated circuit and a specific, dedicated program to perform this specific function and manage the new information that occurs in the process. But there is no such a circuit and program in the present-day computers and robots; all the circuits and programs in their motherboards or mainboards are created to do some specific tasks else that are already predetermined (such as the summation of two digits, the computation of transcendental functions of some digits, and the generation of signals to control other parts: screen monitor, disc drive, mechanical motor, etc.). None is produced to create phenomenal consciousness, i.e., to be aware of and experience something with the awareness and experiences of what that thing is like occurring. (At present, we do not know how to design such circuits and programs yet.) Therefore, it is definite that present-day computers and robots, with the only circuits and programs that they have now, do not and cannot have phenomenal consciousness (5). (However, this does not mean that computers or robots will never be able to have phenomenal consciousness. If they are equipped with circuits and programs that can create phenomenal consciousness, they will have phenomenal consciousness. The problem is, currently, we do not know how to build such circuits and programs yet.)
At this point, some may argue that phenomenal consciousness is a non-material phenomenon and may just occur in the computer without the function of any circuit. However, if it occurs without the function of any computer circuit, it will not and cannot have any physical effects on the computer. This is because physical effects in the computer occur via the functions of their circuits only. Such a physical-effect-deprived phenomenal consciousness is physically irrelevant and is different from phenomenal consciousness that occurs in humans, because phenomenal consciousness that occurs in humans has physical effects on humans – our behaviors are definitely affected by phenomenal consciousness. For example, we think, talk, and write about it; we have conferences and debates on it; and we do researches and experiments on it. We even physically discuss it right here right now. Therefore, although physical-effect-deprived phenomenal consciousness in computers/robots is theoretically or philosophically possible, it is not the kind of phenomenal consciousness that we have and that we are discussing here. (5)
In conclusion, because the consciousness parts other than the phenomenal part do not differentiate us from AI and, without the phenomenal part of consciousness, even the most intelligent and capable brain will function just like the CPUs of present-day AI and because present-day AI do not and cannot have the phenomenal part of consciousness as we do, the phenomenal part of consciousness is unique for us and is the hallmark of our consciousness. Therefore, philosophically, it can be considered that the phenomenal part is the most important part of consciousness.
Q (the edited question): Which aspects of consciousness are most often addressed by philosophers of mind?
A: From the references below and its references inside, and the abundance of philosophical literature about the hard problem of consciousness, the explanatory gap, and the mind-body problem, I think the phenomenal aspects and these three aspects of consciousness are most often addressed by philosophers of mind. (6-10)
Chalmers DJ. Facing up to the problem of consciousness. J Conscious Stud. 1995;2(3):200-219.
Van Gulick R. Consciousness. In: Zalta EN, editor. The Stanford Encyclopedia of Philosophy.
Velmans M. How to define consciousness – and how not to define consciousness. J Conscious Stud. 2009;16(5):139-156.
Rosenthal D. Concepts and Definitions of Consciousness. In: Banks WP, editor. Encyclopedia of Consciousness. Amsterdam: Elsevier; 2009:157-169.
Ukachoke C. Chapter 6: Consciousness In: The Basic Theory of the Mind. 1st ed. Bangkok, Thailand; Charansanitwong Printing Co. 2018.
Brogaard B, Electra Gatzia DE. What Can Neuroscience Tell Us about the Hard Problem of Consciousness? Front Neurosci. 2016;10:395.
Chalmers DJ. Moving forward on the problem of consciousness. J Conscious Stud. 1997;4(1):3-46.
Weisberg J. The hard problem of consciousness. The Internet Encyclopedia of Philosophy.
Nagel T. What is the mind-body problem? Ciba Found Symp. 1993;174:1-7; discussion 7-13.
Smart JJC. The mind/brain identity theory. In: Zalta EN, editor. The Stanford Encyclopedia of Philosophy.