Consciousness, Self, and the Prefrontal Cortex

cartesian-theater

There is a basic question that must be addressed when pondering the nature of consciousness, and that is: why have consciousness at all? The brain processes a great deal of information below the level of conscious awareness, from visual to auditory to tactile, and then the integration of all of these before they can be brought into conscious awareness. Yet conscious awareness itself seems much more limited in the amount of information that it can handle at a time—5 to 9 “chunks” of information, at a time, it would seem. So why rely on conscious awareness as heavily as we do? It certainly seems, at least from this angle, much less able than non-conscious processing—yet, given its apparent efficacy in raising humanity to the heights of culture and insight that we enjoy today, it surely has something essential to offer us.

The prefrontal cortex is the latest structure to appear in the evolution of the brain, and is the structure that shows the greatest development between humans and our closest biological relatives. Furthermore, it is known to mediate a great deal of the abilities considered distinctly human, such as planning, reflection, and empathy, all of which apparently require conscious awareness. Surprisingly, however, a vast abundance of the projections that the prefrontal cortex sends back to more primitive, sub-cortical structures are inhibitory—they function largely to suppress activity in these regions. In fact, this has led several researchers to rethink the concept of free will and, somewhat amusingly, refer to it rather as “free won’t,” in that we are mainly choosing what not to do, of all of the responses recommended by sub-cortical structures. And this is where we might find a reason for conscious awareness.

Consciousness relies on a crucial ingredient for dealing with the world in the way that the prefrontal cortex specializes in doing: it removes behavior from the moment-to-moment sensory perceptions incessantly presenting themselves to sub-cortical brain regions. Instead of constantly responding to each and every stimulus as it comes in, consciousness introduces a disconnect that allows reality apart from oneself to be treated as perceived, and thus distinct from the self and manipulable. Non-conscious responses don’t require perception in the same way that conscious processes do. In order to consciously ponder a course of action while planning, you need a virtual representation to work with, and in order to do that, you need some distance between yourself and the object being represented. Every day perceptions such as the visual field in front of you may function in a very similar manner: a stimulus presents itself, is processed by sub-cortical structures, and then a course of action is offered up to conscious awareness to be chosen or discarded by conscious reflection. There is a whiff of “opponent processing” going on in this narrative, something that comes up a lot in systems biology: two structures working in opposite directions in order to better center around a single desired outcome. Non-conscious, sub-cortical processing is largely reactive, leading to sometimes extreme, reflexive responses; conscious prefrontal processing, on the other hand, divorced from the constant demands of the environment, is more receptive to multiple courses of action, but can sometimes leave us unable to settle on an alternative. With the two of these working with opposing aims, however, behavior that is reactive enough to survive, but receptive enough to be a functioning member of society, can be attained.

This is far from a coherent theory or hypothesis, but the parallels between the roles of sub-cortical and non-conscious processes on the one hand, and prefrontal and conscious processes on the other, along with the connections between the two, are surely going to be important in mapping human consciousness.

Conversations on Consciousness

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Since the spring semester is now in full swing, it has been increasingly difficult for me to devote the necessary time to a full-length treatment of consciousness as I would like. This in mind, I picked up a copy of Susan Blackmore’s Conversations on Consciousness the other day, and I have not regretted it. It serves as an informal introduction to several competing theories and views on the scientific study of the brain and conscious experience. The set-up of the book is simple: interviews with the researchers/philosophers themselves explaining their theories in their own, colloquial way. Add to this a few questions on free will and the fate of consciousness after death, and you get twenty of the most interesting conversations that I’ve ever had the pleasure to read. They allow, among other things, the chance to see these researchers as actual people, and not simply as objective reporters of experimental results as happens far too often.

I have only one complaint about the book, which you may have guessed given the author, Susan Blackmore. Put simply, Blackmore endorses a few very fringe (and some, myself included, would say absurd) ideas about the nature of consciousness. Normally, this would not be an issue—everyone is entitled to their own opinions, and I often disagree with the authors that I read. The complaint comes, however, in the questions that Blackmore chooses to ask her interviewees. The book is accompanied by the sub-script, “What the Best Minds Think about the Brain, Free Will, and What it Means to be Human.” At times, though, it seems like it would read more accurately as, “What the Best Minds Think about My Ideas about the Brain, Free Will, and What it Means to be Human.” This is not over-riding, and most of the time the book stays true to its stated purpose (I thank the interviewees for most of this, they do a good job sticking to what they believe are the real issues), but it is, at times, distracting. It is not enough to knock this down as a great book, well worth reading, but it is something that should be noted, nonetheless.

I would like to give this five out of five stars—it was great fun to read—but the above complaint makes me unable to do so. That said, I would give the interviewees five out of five stars and Blackmore four out of five stars, so let’s say that the book as a whole gets four and a half out of five stars.

Brief Thoughts on the Analogy with Vitalism

It is sometimes asserted that consciousness and many of its aspects are illusory. Some of this, I believe, may turn out to be true. For example, our naive conception of conscious will seems to be at least partially illusory (see here and here for my views on that). Some, however, claim that even such fundamental notions as our sense of self are illusory, finally claiming that consciousness as a whole will one day be explained away as an illusion. I, as you may have guessed, take serious issue with this claim.

A common line of argument taken to support the claim draws an analogy between the present situation and the endeavor to explain life some hundred years ago. There were, in those days, the vitalists. These were the theorists who could not imagine that dead matter and its interactions could account for all that there is to complex life—there had to be something extra, some elan vital, or life force, underlying all of this. Even if we explain heredity, reproduction, growth, etc., we will still be missing something—namely life itself. We now know that they were wrong, dead wrong, and that, in fact, there is simply dead matter interacting in specific ways that leads to the formation of complex, living organisms.

Now take the assertion made by many contemporary philosophers of mind: even if we explain vision, intelligence, emotion, etc. (i.e., the so-called “easy problems” of consciousness), then we will still be missing something—namely consciousness itself. If we explain all of those things that can be worked out computationally, then we will be missing the very thing that we sought to explain in the first place: subjective, conscious minds. But is this necessarily the case? Might consciousness simply fade away the more and more we know about these other processes? Maybe consciousness is simply the elan vital of philosophy of mind, say proponents of this analogy.

This could not be further from the truth. When it came to explaining life, a higher-level property such as the elan vital was postulated to account for something that we did not know the cause of: the difference between living and dead objects. When it comes to consciousness, we are not postulating something above and beyond what we already know. In the words of Descartes, “I think, therefore I am.” His dualism may have been misguided, but he was spot on in stating that there is nothing that we know with more certainty than that we are conscious, that we are our own self. In this way, the analogy is deeply flawed. Something can only be explained away if it was postulated to explain something that we know to be true. Consciousness, however, was never postulated. Instead, it was the very phenomenon that we set out to explain. We may be wrong about the details, and in all likelihood we are, but we are not, as a matter of fact, wrong when we state that we are conscious beings, that consciousness is a real, existing phenomenon that begs explanation in its own right.

Reblog: Problematical Property Dualism

 In the philosophy of mind, non-reductive materialism is a position taken by people who are convinced that there are non-material properties, yet still want to maintain a monistic ontology, while distancing themselves from idealism. Generally, this position entails a substance monism combined with property dualism. So, there is one kind of substance in which physical and mental properties are both instantiated. A brain would then be composed of a material substance which has both mental and physical properties.

This view is usually combined with the thesis that mental properties supervene onto physical properties, but are not reducible to physical properties. So, any substance S that has mental property Q will have physical property P; and it is necessarily the case that if  S has Q then is also has P. That is the general supervenience thesis held by non-reductive materialists who endorse property dualism.

There is a problem with this account of the mental, though. If there was a certain time in the past when there were no mental properties (a time before the existence of life complex enough to instantiate said properties), then there must be a time at which mental properties instantiated. It seems as though there’s literally a moment when mental properties didn’t exist, then they were ‘zapped’ into existence by whatever it was that instantiated the mental properties. It seems very implausible that such an account is true, given a monistic, materialist ontology. However, on substance dualism, the existence of non-material/non-physical properties like the ones endorsed by the property dualist is a plausible possibility. So, the moral of this story is that non-reductive materialism doesn’t seem as plausible as a substance dualism, given the existence of non-physical properties. If the materialist doesn’t find substance dualism plausible for the many reasons many philosophers of mind do, then the materialist may want to bite the bullet and give up his commitment to non-physical properties (unless he or she wishes to become a substance dualist).

My thoughts are re-printed below:

If I agreed that mental states had to “zap in” at some point in the past, then I would find this objection more appealing. That said, property dualism does not require that this occur. A more faithful property dualism would say, rather, that some form of “phenomenal character” existed at all points in the history of the universe, but this is not to say that it has to be recognizably “mental,” as we think of it today. The distinction between “physical” and “mental” is irrelevant to the discussion of property dualism—and philosophy of mind in general, I think, as everything mental is, so far as we can tell, necessarily physical is some way*—it is the distinction between objective and subjective that is most important. Each side of this more refined distinction has fundamentally different tools of explanation, and this is what I think of as a true property dualism.

*for support, I rely on a simple principle from Christof Koch: “No matter, never mind.”

via Problematical Property Dualism.

Minds, Brains and Science

mindsbrainsscience

John Searle’s Minds, Brains and Science is a collection of the six Reith Lectures that he gave in 1984 on the relation between our conscious, meaningful, phenomenal experiences and the backdrop of nonconscious, meaningless, objective physical reality against which all of the former inevitably play out. Essentially, the problem is this: We experience things, but everywhere else we look in the universe, we do not see experiences. How do we explain this seemingly trivial fact and make consciousness fit in with everything else we know?

This is inevitably a question that he is unable to provide a clear answer for, but, nonetheless, this was a successful, and worthwhile, work. The lectures were intended for a lay audience, so they are largely non-technical, but as far as I can tell, none of the necessary content was lost. Searle is still able to explicate each of the sub-problems and arguments very well. He manages to minimize caricaturing his opponents while simultaneously keeping the focus on what, he thinks, are the real issues. All the while, he manages to introduce several new ideas. His remarks on the social sciences and the freedom of the will are especially noteworthy.

In its entirety, the read comes down to less than a hundred pages, making it a perfect introduction to the problem at large. At the same time, it retains enough depth to catch the eye of even the most weathered philosopher-scientist—and for that, I give it five out of five stars.

Searle in Two Quotes

Today, I am reading John Searle’s Minds, Brains and Science, which is essentially an edited transcript of his 1984 Reith Lectures. I read two quotes that I thought were worth sharing, one for its humor, and the other for its insight. Enjoy!

Various replies have been suggested to this [the Chinese Room] argument by workers in artificial intelligence and in psychology, as well as philosophy. They all have something in common; they are all inadequate. And there is an obvious reason why they have to be inadequate, since the argument rests on a very simple logical truth, namely, syntax alone is not sufficient for semantics, and digital computers insofar as they are computers have, by definition, a syntax alone.

I think that he is almost certainly right here, but the manner in which formulates this paragraph is nothing short of comedic perfection. My own thoughts on the subject can be found in my article “Minds and Computers.”

Suppose no one knew how clocks worked. Suppose it was frightfully difficult to figure out how they worked, because, though there were plenty around, no one knew how to build one, and efforts to figure out how they worked tended to destroy the clock. Now suppose a group of researchers said, ‘We will understand how clocks work if we design a machine that is functionally the equivalent of a clock, that keeps time just as well as a clock,’ So they designed an hour glass, and claimed: ‘Now we understand how clocks work,’ or perhaps: ‘If only we could get the hour glass to be just as accurate as a clock we would at last understand how clocks work.’ Substitute ‘brain’ for ‘clock’ in this parable, and substitute ‘digital computer program’ for ‘hour glass’ and the notion of intelligence for the notion of keeping time and you have the contemporary situation in much (not all!) of artificial intelligence and cognitive science.

 

Consciousness: Confessions of a Romantic Reductionist

Consciousness: Confessions of a Romantic Reductionist

Christof Koch’s autobiographical work Consciousness: Confessions of a Romantic Reductionist is just that: his confessions relating to his career, and why he does what he does. I’m going to keep this review short, since this book is not primarily about his own theories. Instead, he takes this book as a chance for him to drop his professional guise and explain why, deep down, he believes certain facts about the universe to be the way that they are. He does not pretend to have pristine motives, or that he only ever disagrees with other researchers based purely on an objective, reflective foundation. He states very clearly his most fundamental beliefs about the topic at hand. He talks, quite honestly, about his lifelong struggle with religion, about his relationship with Francis Crick, about his love of dogs—about anything and everything that he thinks is relevant to, as before, why he does what he does.

For anyone fed up with the sterility and impersonal nature of research on consciousness, this will be a long-needed breath of fresh air. It will be especially useful, I think, for those partaking, or aspiring to partake, in the great quest for consciousness themselves. In particular for those still aspiring, it may be nice to see, explicitly, that a larger-than-life researcher, decades into his own quest, still has some of the same doubts and moments of personal struggle that you may be faced with ever too frequently. Of note, this same researcher who spent 30 some years of life searching for a truly “reductive” explanation of consciousness endorses in this book, quite clearly, property dualism. Take that as you will.

Five out of five stars, one of my new personal favorites. Be sure to check out the cover art, it’s quite impressive.

A Brief Overview of Integrated Information Theories of Consciousness

I have posted before on the proposed relationship between information theory and conscious, phenomenal states. For a brief background, consider the following: Information states have two fundamental attributes, one being intrinsic and the other extrinsic, the latter of which can also be called “relational.” Take, for example, one bit of information, say 11001101. In this bit, a sequence of 1s and 0s stands to mean something when it is called upon. The individual 1s and 0s can be labelled as the intrinsic elements. The extrinsic aspect, then, refers to the internal structure of the bit, which is where the term relational comes in. Each element has a definite position within the bit—there is a 1 in the first position, and a 0 in the third position—which marks where it is relative to all of the other elements. We can apply this to consciousness research, some say, by thinking of the intrinsic elements as the subjective side of an issue, or what it is like to be something. On the other hand, the relational parts represent the third-person perspective that we take when we study physics (that is, when the study the relations between fundamental things. This is why, as I have commented before, physics is utterly hopeless when it comes to understanding phenomenal consciousness).

Now, the view of Integrated Information theorists takes this a step further. (If we weren’t to clarify the relationship between information and consciousness, then it might seem like we were saying that anything and everything that has an information state—e.g., a thermostat—is therefore conscious, in some, perhaps limited, fashion. Some, the panpsychists, do say this, but this is not necessarily the view from Integrated Information.) They claim that the phenomena of consciousness, while in some ways fundamental to information states, also depends on the integration and differentiation of those information states. Our brains, along with those of many mammals and “lower” species, do an excellent job of fulfilling these requirements. Through less-than-clear mechanisms, our brains are able to both synchronize activity at a global level, but also keep information very well stratified throughout the layers and structures contained therein. For a counterexample, think of the brain during an epileptic seizure: information is everywhere, with electrical signals firing at multiple locations simultaneously. It could be said that this represents a form of integration, but this situation also clearly does away with any sort of differentiation. As predicted, seizures are generally accompanied by a loss of consciousness, or a diminished conscious state at most.

It is still hard to see how exactly the tenets of this theory might explain the “why” of consciousness, but it presents, at the least, some interesting ways to think about the “how.”

Determinism, or Indeterminism: That is not the question.

In my Metaphysics class today, the following argument was put up for scrutiny:

1) If determinism is true, then no one acts freely, ever.

2) If indeterminism is true, then no one acts freely, ever.

3) Either indeterminism is true, or determinism is true.

4) Therefore, no one ever acts freely, ever.

5) If no one ever acts freely, ever, then no one is ever responsible for their actions.

Premise 1, in brief, relies on that assumption that if the world is deterministic, then everything that happened today was a necessary consequence of what happened millions of years ago. If everything that happened today was a necessary consequence of events in the distant past, then no person has any control over the present—it is all set in stone, as it were. Free will dictates a certain amount of control over present actions, so if this control is absent, then so is free will.

Premise 2, on the other hand, relies on a purely probabilistic definition of indeterminism. If events are indeterministic, which is to say that they are merely an odds game with event A having a 40% probability, and event B having a 60% probability, then we still lack any sort of “control” over the situation. Which event occurs is largely arbitrary, relying only on some unknown odds, written in the sky or otherwise.

This is not to say that these are the only ways in which premises 1 and 2 can be formulated, but this is how they were presented in this case.

Most of the objections raised, both in my class and in the literature, from what I’ve seen,  have attempted to disprove either premise 1 or 2. That is, there can be free will under determinism, or there can be free will under indeterminism. Most of these amount to some re-formulation of free will. I will not be taking either of these positions. Instead, I will attack premise 3: That the world is either deterministic or indeterministic.

The core of my argument rests on the claim that premise 3 presents a false dilemma. It is either determinism, or it is indeterminism, but not both. I assert that it is, indeed, both, or at the very least, we are not in a position to rule this possibility out. Current physics, which is where most of these theories claim to have their support, does not itself claim to have sorted this issue out. We know that under certain circumstances, such as when the scale is microscopic, that the world behaves in an apparently indeterministic way. Under other circumstances, such as when the scale is macroscopic, the world behaves in an apparently deterministic way. Many propose that we can link these two, and show that it is really one, and not the other, in virtue of a fundamental property of nature: namely parsimony—or, that the universe is, at its most fundamental, simple (simple in the sense that it all can be reduced to more or less the same thing). But, what they miss, is that it does not have to be this way. There is, in fact, no law that says that the universe must be simple. It may very well turn out that the universe is complicated, perhaps even too complicated for us to understand it, in the proper sense of the word.

(The following is mere speculation, I have absolutely no empirical basis for the ideas that follow; however,  I still, personally, find a great deal of plausibility in them, but you have been warned, nonetheless!)

Building off of this, and the fact that most of the arguments that place free will either in a purely deterministic or a purely indeterministic light typically have to resort to a reformulation of free will itself, I now assert that free will is only a coherent construct in a world that is both deterministic and indeterministic. What I propose is the following, which relates this more specifically to the theme of this blog: free will can only exist in conscious creatures. This may seem unnecessary to state in so many words, but the following should provide reasons for it. Complex brains are, in a general sense, specialized organs for planning and deliberation. Given that the microscopic events of this world are largely indeterministic, and that the macroscopic events are largely deterministic, we can postulate the following: brains serve to make sense of a vast multitude of indeterminacy. Through the process of evolution, and, to steal a phrase from a neuroscientist I once knew, thanks to the goddess of molecular evolution, they came to be in a position to turn underlying indeterminacy into coherent, conscious actions. This is not an appeal to a “collapse-of-the-wave-function” view of consciousness, to be clear. Rather, it is an attempt to reconcile the disparate aspects of reality into one coherent framework.

We can use this argument to strike down some of the objections raised to both purely deterministic and purely indeterministic accounts of free will. One variety of the former asserts that if you could not have acted otherwise, then you could not have acted freely, as stated above. If there is some underlying indeterminacy, however, this is clearly not the case. There are, in fact, a multitude of different ways in which you could have acted. Aha! But this just reduces to a variety of the argument from indeterminacy—that actions are merely arbitrary instantiations of probabilities, right? But that is where the deterministic aspect of reality kicks in. Once the most basic underlying facts about the world are set, in a probabilistic fashion, then determinism takes over. For this, I draw on an idea put forth by John Searle: downward causality, but in no way do I claim to restate his argument. The higher-order functions of the brain, namely consciousness, do indeed have “causes” that exist as smaller, microscopic bits, but these higher-order functions also have the ability to rain down causation on these smaller bits, much in the way that higher-order theories of economics can influence the activities of lower level commodities. Neither of these can be “smoothly reduced,” as Searle puts it, to the other, but that does not imply that one or the other does not exist, or play a meaningful role. In fact, Searle says that typically, reduction of one thing to another serves the purpose of showing that one of those things does not exist, not the other way around, as is often claimed.

This may seem counter-intuitive, and in some ways, it does have to re-formulate the popular idea of free will. In particular, it draws a distinction between free will at its most basic on the one hand, and conscious will on the other. Conscious will, or the idea that you are consciously in control of all of your actions and thoughts, is inevitably false. A handful of psychological experiments demonstrating non-conscious biases and predispositions shows this very simply. But this is not what we are talking about when we say free will, or so I claim. Free will is much more general than the limited definition of conscious will. At its most basic, it requires that you be capable of acting in certain ways that rely on intentional stances. Even if you are not consciously aware of your decisions to act in certain ways, it is still you that is making them. You are your brain, and everything that comes along with it. Simply because something is non-conscious does not make it any less a part of you. It may clash with the popular account of who you are, but at the end of the day, you are made up of more non-conscious pieces than conscious pieces, so restricting our definition of free will to the conscious pieces seems to make little sense. Now, this is not to say that our conscious feeling of free will is irrelevant, but it is a different matter to bring up—specifically, it is more of an epistemic question than a metaphysical question.

The Problem, continued

John Tyndall, 1868:

The passage from the physics of the brain to the corresponding facts of consciousness is unthinkable as a result of mechanics. Granted that a definite thought, and a definite molecular action in the brain, occur simultaneously; we do not possess the intellectual organ, nor apparently any rudiment of the organ, which would enable us to pass, by a process of reasoning, from the one phenomenon to the other. They appear together, but we do not know why. Were our minds and senses so expanded, strengthened, and illuminated, as to enable us to see and feel the very molecules of the brain; were we capable of following all their motions, all their groupings, all their electric discharges, if such there be; and were we intimately acquainted  with the corresponding states of thought and feeling, we should be as far as ever from the solution of the problem, “How are these physical processes connected with the facts of consciousness?” The chasm between the two classes of phenomena would still remain intellectually impassable. Let the consciousness for love, for example, be associated with a right-handed spiral motion of the molecules of the brain, and the consciousness of hate with a left-handed spiral motion. We should then know, when we love, that the motion is in one direction, and, when we hate, that the motion is in the other; but the “WHY?” would remain as unanswerable as before.