Jackson's special interest is the philosophy of mind, especially the problem of physicalist or reductionist explanations of mind. Physicalism is the view that the entire contents of the world are matter alone, atoms and the void. Immaterial entities, such as mind, are merely epiphenomena, a byproduct of brain activity, with no causal effect on the material world.

But what then is human knowledge? Does knowledge not affect our world every day? Jackson may be best known for his "knowledge argument" against physicalism — against the view that the universe consists entirely of the kinds of entities described by physics. His prime example of the knowledge argument is a scientist named Mary who lives in a black and white room and sees the outside world through a black and white television monitor.

Mary is a brilliant scientist who is, for whatever reason, forced to investigate the world from a black and white room via a black and white television monitor. She specialises in the neurophysiology of vision and acquires, let us suppose, all the physical information there is to obtain about what goes on when we see ripe tomatoes, or the sky, and use terms like 'red', 'blue', and so on. She discovers, for example, just which wave-length combinations from the sky stimulate the retina, and exactly how this produces via the central nervous system the contraction of the vocal chords and expulsion of air from the lungs that results in the uttering of the sentence 'The sky is blue'...

What will happen when Mary is released from her black and white room or is given a colour television monitor? Will she learn anything or not? It seems just obvious that she will learn something about the world and our visual experience of it. But then it is inescapable that her previous knowledge was incomplete. But she had all the physical information. Ergo there is more to have than that, and Physicalism is false.

("Epiphenomenal Qualia", The Philosophical Quarterly 32.127 (1982): 127-136.)

But isn't it clear that Mary did not have all the information? In particular, even if told everything about every physical and biological process others use to see the color red, Mary has never had the experience of seeing the color red, the difficult to define "qualia."

Once Mary has experienced color, she has learned more, she knows more.

But surely Mary's personal information content and her experiences, in short, her "knowledge," can not alone count as evidence that "physicalism is false."

In his more recent work, Jackson questions his earlier "strongly held intuitions...that there is something seriously incomplete about any purely physical story about the mind"

Most contemporary philosophers given a choice between going with science and going with intuitions, go with science. Although I once dissented from the majority, I have capitulated and now see the interesting issue as being where the arguments from the intuitions against physicalism—the arguments that seem so compelling—go wrong.,,

The epistemic intuition that founds the knowledge argument is that you cannot deduce from purely physical information about us and our world, all there is to know about the nature of our world because you cannot deduce how things look to us...

[Mary] is, despite [her] artificial restrictions, extraordinarily knowledgeable about the physical nature of our world, including the neurophysiology of human beings and sentient creatures in general, and how their neurophysiology underpins their interactions with their surroundings. Can she in principle deduce from all this physical information, what it is like to see, say, red?

("Mind And Illusion", The Philosophical Quarterly 32.127, 1982, p.127)

The ERR model is an extension of neuroscientist Donald Hebb's famous insight that "neurons that fire together wire together." Our experience recorder and reproducer ERR model simply assumes that "neurons that have been wired together will fire together." It is our model for "learning" and "memory" in all living things.

We propose that the ERR can in principle reproduce the entire complex of past sensations experienced, together with the emotional responses to the original experience (pleasure, pain, fear, etc.). Playback of past experiences may be stimulated by anything in the current experience that resembles something in past similar experiences.

The ERR model stands in contrast to the popular cognitive science or “computational” model of a mind as a digital computer with a "central processor" or even many "parallel processors." No algorithms or stored programs are needed for the ERR model. There is nothing comparable to the addresses and data buses used to store and retrieve information in a digital computer. Analog "action potentials (electrical discharges) simply travel along the branching neural networks that were connected together by past experiences.

Later firing of even a part of the previously wired neurons can stimulate firing of all or part of the original complex, thus "playing back" similar past experiences (including the critically important emotional reaction to those original experiences), without which a genuinely new experience lacks the context needed to give it "meaning" and produce the "feelings" that accompany the "qualia," Thomas Nagel's "what it's like to be..." and Jackson's "what it's like to see...," the color red, for example.

Mind And Illusion, Royal Institute of Philosophy Supplement, 2003, pp.251-272.