Is Consciousness an Epiphenomenon: Extended Discussion

If the question or some of the words in the title are unfamiliar to you, it means: could consciousness be something that exists, but is simply a by-product of brain activity with no actual impact on how we behave? In other words, our brain activities produce our behavior, even if we’re aware of some of what goes on in those brain activities, and our awareness doesn’t impact how we behave.

But of course, we know why we do things. Don’t we?  Don’t we make conscious decisions and then behave according to them? If the answer to the question in the title is no, then we only think we know why we do things and we only think we behave according to our conscious decisions. Such a suggestion sounds obviously wrong. It doesn’t square with our experiences. Yet this is exactly what some psychologists, neuroscientists and philosophers are now saying. They are in a minority, but I think their arguments are worth considering.

Why does the answer to the question matter? For many people, if our conscious decisions don’t cause our behavior, what happens to the concept of free will? It turns out that the answer to that question is almost as difficult to arrive at as the question of whether consciousness has an effect on behavior, so I will postpone that discussion. For my part, I want to know the answer because I am curious, about the human mind, and because I write books about AIs, robots, and androids and I’ve had to deal with the issue of whether machines can be conscious. But if consciousness doesn’t affect behavior, perhaps it isn’t an important question to ask about machines.

Let’s start with a definition of consciousness. Philosopher Ned Block has proposed a division of consciousness that has fairly wide agreement and has fostered a great deal of psychological research. Block divides consciousness into two types:  P-consciousness, which is phenomenal consciousness, our awareness of sensations, and perception–those originating in our own body and those originating from the world around us— our emotions and our thoughts. These are private events and we assume, but cannot know, that other people have similar experiences. The second type is A-consciousness or accessconsciousness, which is our directed consciousness, which we use to control what we think about, to reason, to plan and to solve problems as well as to make decisions. Humans have both types of consciousness and perhaps some animals, such as chimps, do too. Many animals have only P-consciousness, they are aware of their environment and their sensations, but cannot make cognitive plans regarding how to behave. It’s conceivable that some simple animals, bacteria, amoeba, etc are not even conscious of their environment, although they are able to react to it, much like a machine that reacts to an external stimulus, but we would not say it is conscious of the stimulus  (my robotic vacuum cleaner, for instance).

It’s not difficult to conceive that P-consciousness is an epiphenomenon, a by-product of our brain activity that has no function other than to make us aware of ourselves and our environment. We can’t control it. You can’t look at a tree and decide not to see it. Your sensory processing of information happens in parts of your brain that are not under your control. It’s not simple, as any study of brain function will demonstrate, and it involves many steps and many specialized nerve and brain networks  to happen, but we are not aware of these and cannot affect them (except to shut our eyes, plug our ears, or anesthetize our body sensations). Special training may allow us to not attend to them, but that is a process involving A-consciousness. Even learned, complicated perceptions occur without us controlling them. Try, for instance, to not read the following three letters as a word: the. It happens outside of your conscious control, even though it took you a long time to learn how to do it. Well-practiced behaviors that required a great deal of attention while learning them, often can be carried out without our awareness once they become a habit. This includes things like simple math: 2+ 2= 4, recognizing a familiar face, remembering a name, driving a car on a familiar road. A common piece of advice to a graduating senior who has to climb steps to a stage to receive their diploma is “don’t think about your feet as you climb the steps or you’ll trip.” It’s better to let automatic processes control your habitual behavior than to try to use concentration and deliberation.

So what about A-consciousness? I may be able to say 2+2=4 without thinking about it, but I can’t solve a quadratic equation without deliberately searching my memory for the formula. Very accomplished mathematicians can. The formula pops into their heads as easily as 4 pops into mine when asked “what is 2+2?” But most of us can’t. We have to search our memory or, more likely, search the internet or a math text. And we decide to do this and we decide where to search, don’t we? Yes and no. The request to solve a problem that is presented as a quadratric equation, ax^2 +bx+ c, is a verbal cue (or if you are taking a test, a written, visual cue) that prompts a memory that there is a formula for this. Are we aware of how we remembered that? Not usually. We just know that there is a formula and we may even remember the teacher who taught it to us, but we don’t know how we remembered that. We then have to determine if the formula is in our memory and if it is readily accessible. Are we aware how we determine this, other than we simply know it? Not usually. Presumably our brain does some sort of memory search, perhaps resembling, at least metaphorically, us going through the index of a book to see if it mentions the quadratic formula and where it is located in the book. But we are not aware of how that search process is carried out. Once we arrive at the formula we either understand it or we don’t. We either remember how to use it or we don’t. If we do, we are not aware how we know how to understand and use it, we just are. So we solve the problem…. or we give up and don’t solve it. Isn’t that a conscious decision?  It’s a decision we are conscious of making, but that is not the same as requiring our consciousness to make the decision. Perhaps we are just aware of what our decision is. We can even be aware of the reasons for it, or at least some reasons, enough to make sense to ourselves or even to others if we have to explain our behavior to them.

So we are aware of using our A-consciousness to solve a problem and aware of some of its operations, although mostly as the outcome of those operations. We don’t have an experience of them being carried out (we can write the process down, which makes it easier to carry out, since it reduces the load on working memory, but it still comes down to how we know what to write down, how we know how to carry out the steps, e.g., divide the top numerator by the denominator, all of which just “”pop into our heads”). Our conscious thoughts are mostly the results of the operations that occur automatically below our level of consciousness. But are those conscious thoughts necessary to solve the problem. I can easily imagine a computer program that is set up with solving math problems as its goal (it’s goal is to accumulate points by solving math problems, and for every problem it solves within a limited time frame, it gets a point – sorta like programming it to take the SAT-Math section). It encounters a problem presented as a quadratric equation, e. g., 5X^2 + 6x +1=0, and is asked to find x. The form of the problem is highly associated with “quadratic equation” in its memory. The problem, combined with the instruction to solve it is associated with “quadratic formula.” It searches its memory for the quadratic formula, follows a prescribed sequence of steps to solve the problem using the formula and outputs the answer, or… failing to find the formula or the set of steps to use with the formula, it outputs “skip this problem.”  Did the computer have to be aware of what it was doing? No.  Suppose the computer were a copy of a human brain (as in my novel, Ezekiel’s Brain) and, in addition to following the steps needed to solve the problem, it outputted the results of each step into awareness, e.g., search> “I found it!”; following the steps> “I’m following step 1, now step 2, etc. ; solution> “Here’s my answer.” Of what use would this latter function of outputting the results of each step into awareness be?  To the computer, it would not be useful. It is aware of what it is doing, but its awareness is ans epiphenomenon; it doesn’t affect the actual operation of solving the problem. However, suppose that it was a “teaching computer.” How would it respond to the request, “tell me how you did that?” It could recite the steps it took. If it recorded what it was aware of, it could consult its own record if it forgot how to do the problem. In much the same way, our awareness may not be crucial for solving problems, but it provides a rough description of what operations are necessary to solve the various problems so we can remember them, and so we can pass them on to others, or if they are operations that produce errors, we can tell someone what we did and they can correct our approach by suggesting doing something else.  In other words, it allows us to pass on knowledge and assist each other in solving problems. Evolution selected consciousness as a product of brain operations because passing on knowledge and helping each other solve problems helped humans survive.

If the above explanation makes sense to you, then perhaps you can understand that regarding consciousness as an epiphenomenon is not so far-fetched as it seems. It may be incorrect, but it is not impossible. It will be difficult to prove, because it is somewhat like proving a negative. No matter how many brain operations can be shown to be carried out without the necessity of consciousness, there could always be one more that appeared to require it. The answer to the question is important, not just so we can understand humans, but to determine if it is necessary to make artificial intelligence devices conscious in order for them to do everything humans do (cognitively, that is).  It also might mean that, should we encounter an alien civilization someday, we might not be able to assume that because they are intelligent, they are conscious.  It could alter our assessment of our fellow creatures here on earth. Must the most intelligent animals (chimps, porpoises, whales) also be conscious? These are interesting questions with lots of implications.



Block N. (1995). On a confusion about a function of consciousness. Behav. Brain Sci. 18, 227–287. 10.1017/S0140525X00038188

Halligan, P. W., & Oakley, D. A. (2021). Giving Up on Consciousness as the Ghost in the Machine. Frontiers in psychology12, 571460.