What Is the Puzzle of Consciousness?
What is the one question that could advance research on consciousness?
Posted August 23, 2021 | Reviewed by Devon Frye
Over the years, many learned colleagues in the field of neuroscience have approached me and asked, “Why do people say that consciousness is a mystery? I just don’t see what the mystery is.”
Oftentimes, these colleagues would add something to the effect of, “I wish there could be one concrete question that reflects what this puzzle is all about. As a scientist, I prefer concrete questions to general statements, and I certainly do not have time to take a course in philosophy of mind.” Another scientist once told me, “I challenge you to come up with one concrete question. It seems to me that there isn’t one.” We are here speaking about the most basic kind of consciousness, such as the experience of a yellow afterimage, nausea, pain, or ringing in one’s ears.
Of course, there is a long answer to these comments from my esteemed colleagues, an answer that could easily occupy an entire semester at a university. But few scientists working in the field have time for such a course. So I thought long and hard about what would be the concrete question that, by itself, could spur empirical research. It would have to be a question that does not require further exposition or too much philosophizing.
It turns out that the concrete question, in my view, is a two-part question:
- What are the key differences between the brain processes associated with consciousness and the brain processes that are not associated with consciousness? In short, what is the difference between conscious and unconscious processes in the human brain?
- How do these differences explain the characteristics of consciousness, that is, how do these differences account for phenomenological data (data about consciousness, aka subjective experience)?
Unlike other possible questions about the nature of consciousness, the two-part question focuses only on humans (the creatures about which we know the most regarding conscious processing) and adopts the notion that, in the brain, there are both conscious processes and unconscious processes, a notion that is not controversial. Thus, if one subscribes to this notion, an acceptable answer to the first question cannot be that all physical things are conscious, all neural activities are conscious, or that all things are unconscious. One must explain the difference between conscious and unconscious processes as they exist in the human brain (not in a computer, plant, or robot).
This difference is not as stark or as obvious as one might suppose. For example, unconscious processes are capable of stimulus detection and, under some circumstances, of issuing motor responses to stimuli. Moreover, unconscious processing can be quite sophisticated, as in the case of syntax, unconscious inter-sensory processing, and motor programming, which is largely unconscious. There are many examples that reveal the sophistication of unconscious processes. After one arrives at a hypothesis regarding the first part of the question, then one has to explain how the hypothesized difference explains phenomenological data, that is, all those observations we have regarding conscious phenomena. These observations, including characteristics of the conscious field, could be about afterimages, pain, earworms (songs that one cannot get out of one’s head), or the manner in which the world is consciously represented (e.g., with railroads apparently converging in the horizon).
Sometimes, a good question can advance research as much as a good answer. I hope that this question makes the mystery of consciousness a bit more tractable.
For a theoretical account that attempts to answer this question, click here.