Qualia

Qualia (singular, quale) is a philosophical term referring to the experiential properties of sensation; the "redness" of red, the "warmness" of warmth, the "garlickness" of the taste of garlic, and so on. By definition, it is impossible to know or understand qualia without direct experience of them, and as a result, they are inherently person-specific and uncommunicable. (One cannot be certain whether or not the "redness" that another sees is experientially identical—or even similar—to the "redness" that one sees, even when looking at the same object.)
The term "qualia" originated in philosophy, although it has been picked up by some scientists (and rejected by some philosophers).

Qualia have become a major component in many modern formulations of the philosophy of mind because of their role in illustrating the difference between knowledge-by-description about, such as might be programmed into a computer, and knowledge-by-acquaintance of, which can only be obtained through direct experience. Computers, like p-zombies, are often assumed to lack qualia and therefore be in some way intrinsically different from humans at a fundamental cognitive level. Whether this is a distinction that actually makes a difference is, apparently, another matter.

Controversies about qualia include:

• Whether qualia exist at all.
• Whether "qualia" is a useful concept/word.
• Whether qualia have interesting epistemological properties, such as being irrefutable and/or ineffable.
• Whether qualia can have unaccountable variations and absences.
• Can computers have qualia.
  • If not, how does that affect AI and mind uploading.
• Whether qualia defy physical explanation/description.
  • If so, whether that is best explained by dualism (qualia are not physical), or by mysterianism

(qualia are physical, but for some reason incomprehensible to humans).
The last dispute is particularly significant. Concern about the problem of qualia (and consciousness in general) is about the only motivation for philosophers to reject physicalism or naturalism that is not propelled by mysticism or religious dogma.


Objectivity and Testability

The concept of qualia has been rejected by some philosophers and neuroscientists as not even wrong, or simply untestable and therefore useless. It also has scientific defenders. It is, after all, hard to dispute that one seems to have qualia, subjectively. One's pain hurts, and one's food has a taste, and so on. Neuroscientist V.S. Ramachandran and philosopher William Hirstein have suggested that one person's qualia could rendered accessible to another once we have the ability to "connect" two brains via some sort of cable. Unfortunately, this technology is a long way off.^[1]
 
Daniel Dennett, like many in the cognitive sciences, characterizes qualia as a useless and unfalsifiable concept, saying that it must be possible to know if a change in qualia occurs and that there is a difference in having a qualia as opposed to not having one.^[2] Simply ignoring any ineffable forms of qualia (or alternatively just redefining them as some measurable property a la Ned Block^[3]) is the de facto position in the cognitive sciences as something must have a measurable effect if you want to do an experiment on it, and consequently, not have your research grant tossed in the garbage bin. Once again, this problem could theoretically be solved if we could hook up two brains Ramachandran-style, but that's currently impossible. As a result, certain versions of qualia tend to be seen as fuzzy or speculative at best with harder versions such as the inverted spectrum tend to be written off as philosophical woo.

 Qualia and Computers


There is, even among naturalists, a widespread apprehension than robots, computers and artificial intelligences would lack human-style emotions, and perhaps even sensation.^[10] It is certainly a staple of science fiction, where androids are by default emotionless, unless of course fitted with an emotion chip. Star Trek's Mr Data is also astonished by "real" touch, when a piece of human skin is grafted onto him by the Borg Queen — whatever tactile sensors he has being fitted with lacking that special something.

Perhaps the origin of the idea lies in the fact that there is no obvious way to program in emotional feelings and sensory qualia. Or perhaps it is because computers and robots are perceived as running on "pure logic", which is seen as a separate faculty to emotion and sensation in humans. A counteragument is that humans are made of matter, and robots are made of matter, and no magic pixie dust is responsible for sensation and emotion in humans.

There are some researchers who think they can programme "artificial qualia" into an AI, but they caution that: a"[w]e are not interested in the problem of establishing whether robots can have real phenomenal experiences or not.^[11]

 What qualia are for
V. S. Ramachandran believes that qualia have a purpose: if an entity has a complex mind with a lot of different things going on, and if it has the ability to manipulate concepts, then it is in danger of paying too much attention to the wrong things, of getting lost in its thoughts. It needs some things to stand out, to be more urgent or compelling than others.^[1] Pain is obviously compelling. Colour is like mental highlighter — in fact, synaesthetes can use mental highlighting to perform some tasks more effectively^[12]. On a related theme, Richard L Gregory has hypothesised that present experience is more vivid than recalled experience because we need to pay attention to the present. If we had perfectly vivide recall of past experience, we might get confused and start reacting to it as though it is happening.<sup>[13]


See the whole article here: http://rationalwiki.org/wiki/Qualia</sup>