The illusion of free will

Discussion in 'General Philosophy' started by barcelonic, Feb 12, 2014.

  1. Sarkus Hippomonstrosesquippedalo phobe Valued Senior Member

    I won't blame you for your error, only the BBC for their editing of the actual comment that Bailey stated: "at the very least we have shown why the digits of pi and log(2) appear to be random: because they are closely approximated by a type of generator associated with the field of chaotic dynamics."
    It does rather change the meaning of the quote, doesn't it.
    I.e. The numbers of pi can be approximated by a system that is associated with chaotic dynamics. It does not mean that pi itself is chaotic (it is just a number) but that systems (including trying to understand what the next digit is from what has gone before) involving pi can be.

    Furthermore, when they refer to the digits of pi being "random" they mean it in a statistical sense: each digit will appear 1/10th of the time, each pair of digits 1/100th of the time etc. I.e. That the number is "normal", and what they have been trying to do is actually prove that pi is such a number.

    But you are correct, the sequencing of the digits of pi can be used in a system if you are going from one to the next, because you are not just taking a constant (pi) but introducing a dynamic... moving from one digit to the next.
    The same way a brick can be used in a system, but the brick itself not being a system.
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  3. Sarkus Hippomonstrosesquippedalo phobe Valued Senior Member

    I have been using deductive reasoning.
    If A = B
    And B = C
    Then A = C
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  5. Quantum Quack Life's a tease... Valued Senior Member

    but what does D equal?
    or put it this way
    What do all other letters of the table NOT equal.
    If referring to A,B and C as being part of a complete system A~Z
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  7. Quantum Quack Life's a tease... Valued Senior Member

    I have a problem with this although initially it appears valid there is a problem I believe.

    For an infinite sequence of digits to be truly random patterns must be allowed to form randomly. [ randomness must be unconditional & unrestricted IMO ]
    Pi appears to prohibit pattern forming which makes it a rather special case. It appears to specifically prohibit that which would randomly appear in an infinite series of digits

    It's a tough bit of reasoning but so far after a few years of testing none have refuted the sensibility of the above.
  8. wynn ˙ Valued Senior Member

    Hmmm ... Does anyone here actually know how to calculate Pi - with pen and paper?
  9. Quantum Quack Life's a tease... Valued Senior Member

    Probabilistic Determinism is about as contradictory as anything else.
  10. Sarkus Hippomonstrosesquippedalo phobe Valued Senior Member

    Ah, you mean you suggest I use inductive reasoning rather than deductive?

    As for D, it rather depends on what it is, and whether the assumptions (A and B) are sufficient to be able to provide a conclusion, or whether it will be underdetermined.
  11. Sarkus Hippomonstrosesquippedalo phobe Valued Senior Member

    No it's not.
    Determinism is the philosophy that states for a given input you get a single output, and the output is exactly the same every time you use exactly the same input.
    Probabilistic determinism is the philosophy that says for a given input you get a single probability function of output, and that the probability function is the same every time you use exactly the same input.

    For example, if a coin toss was deterministic then, if you start with exactly the same starting conditions then you would always get the same result.
    But if it is probabilistically deterministic then if you start with exactly the same conditions then you would always end up with the same distribution of outputs (e.g. One starting condition may lead to a 10:90 split of Heads and Tails, another starting condition might lead to 70:30) but for each starting condition there is a single probability function that describes the possible outputs.

    The issue is when you try to establish determinism through practical means, as it is probably impossible at a practical level to ever have the same starting conditions. But this does not make the situation indeterministic, philosophically speaking. It just puts a practical limitation on testing for it.
    And this is where chaos also rears its head. Because if you can not start with exactly the same conditions then you could (in a chaotic system) end up with significantly different results. But unless you know whether you have started with exactly the same conditions or not (which in practice is likely to be impossible) then you'd an not tell if the output is due to a difference in starting condition or due to inherent indeterminism.

    This is why I also don't think you should confuse or equate indeterminism with unpredictability: as I see it, indeterminism is a philosophical concept that underlies the very nature of interactions, while unpredictability is a practical matter that can be brought about either through inherent indeterminism or through lack of exact knowledge of starting conditions in a system (accentuated through a chaotic system, for example) even where determinism holds.
  12. Sarkus Hippomonstrosesquippedalo phobe Valued Senior Member


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    You could calculate any number of digits you want with pen and paper, if you had enough paper, ink and time.

    The one I know that works quite well is: 3 + 4/(2*3*4) - 4/(4*5*6) + 4/(6*7*8)...

    After 5 terms it gets you to within 0.02 of Pi, and after 10 terms to within 0.00025, and after 20 terms it's less than 0.000032

    It would take time, though.
  13. Magical Realist Valued Senior Member

    Nice try but no. The sequencing of the digits really is chaotic. That's why it can be used as a random number generator. Try again?
  14. barcelonic Registered Senior Member

    Wow what a long thread. And now fractals and pi huh? OK lol

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  15. Magical Realist Valued Senior Member

    I found this article that offers some clarity on what freewill is and whether neuroscience proves it is an illusion or not. It backs up much of what Yazata says about it in his own insightful posts.

    Is Neuroscience the Death of Free Will?


    "Is free will an illusion? Some leading scientists think so. For instance, in 2002 the psychologist Daniel Wegner wrote, “It seems we are agents. It seems we cause what we do… It is sobering and ultimately accurate to call all this an illusion.” More recently, the neuroscientist Patrick Haggard declared, “We certainly don’t have free will. Not in the sense we think.” And in June, the neuroscientist Sam Harris claimed, “You seem to be an agent acting of your own free will. The problem, however, is that this point of view cannot be reconciled with what we know about the human brain.”

    Many neuroscientists are employing a flawed notion of free will.

    Such proclamations make the news; after all, if free will is dead, then moral and legal responsibility may be close behind. As the legal analyst Jeffrey Rosen wrote in The New York Times Magazine, “Since all behavior is caused by our brains, wouldn’t this mean all behavior could potentially be excused? … The death of free will, or its exposure as a convenient illusion, some worry, could wreak havoc on our sense of moral and legal responsibility.”

    Indeed, free will matters in part because it is a precondition for deserving blame for bad acts and deserving credit for achievements. It also turns out that simply exposing people to scientific claims that free will is an illusion can lead them to misbehave, for instance, cheating more or helping others less. [1] So, it matters whether these scientists are justified in concluding that free will is an illusion.

    Here, I’ll explain why neuroscience is not the death of free will and does not “wreak havoc on our sense of moral and legal responsibility,” extending a discussion begun in Gary Gutting’s recent Stone column. I’ll argue that the neuroscientific evidence does not undermine free will. But first, I’ll explain the central problem: these scientists are employing a flawed notion of free will. Once a better notion of free will is in place, the argument can be turned on its head. Instead of showing that free will is an illusion, neuroscience and psychology can actually help us understand how it works.

    When Haggard concludes that we do not have free will “in the sense we think,” he reveals how this conclusion depends on a particular definition of free will. Scientists’ arguments that free will is an illusion typically begin by assuming that free will, by definition, requires an immaterial soul or non-physical mind, and they take neuroscience to provide evidence that our minds are physical. Haggard mentions free will “in the spiritual sense … a ghost in the machine.” The neuroscientist Read Montague defines free will as “the idea that we make choices and have thoughts independent of anything remotely resembling a physical process. Free will is the close cousin to the idea of the soul” (Current Biology 18, 2008).[2] They use a definition of free will that they take to be demanded by ordinary thinking and philosophical theory. But they are mistaken on both counts.

    We should be wary of defining things out of existence. Define Earth as the planet at the center of the universe and it turns out there is no Earth. Define what’s moral as whatever your God mandates and suddenly most people become immoral. Define marriage as a union only for procreation, and you thereby annul many marriages.

    The sciences of the mind do give us good reasons to think that our minds are made of matter. But to conclude that consciousness or free will is thereby an illusion is too quick. It is like inferring from discoveries in organic chemistry that life is an illusion just because living organisms are made up of non-living stuff. Much of the progress in science comes precisely from understanding wholes in terms of their parts, without this suggesting the disappearance of the wholes. There’s no reason to define the mind or free will in a way that begins by cutting off this possibility for progress.

    Our brains are the most complexly organized things in the known universe, just the sort of thing that could eventually make sense of why each of us is unique, why we are conscious creatures and why humans have abilities to comprehend, converse, and create that go well beyond the precursors of these abilities in other animals. Neuroscientific discoveries over the next century will uncover how consciousness and thinking work the way they do because our complex brains work the way they do.

    These discoveries about how our brains work can also explain how free will works rather than explaining it away. But first, we need to define free will in a more reasonable and useful way. Many philosophers, including me, understand free will as a set of capacities for imagining future courses of action, deliberating about one’s reasons for choosing them, planning one’s actions in light of this deliberation and controlling actions in the face of competing desires. We act of our own free will to the extent that we have the opportunity to exercise these capacities, without unreasonable external or internal pressure. We are responsible for our actions roughly to the extent that we possess these capacities and we have opportunities to exercise them.

    These capacities for conscious deliberation, rational thinking and self-control are not magical abilities. They need not belong to immaterial souls outside the realm of scientific understanding (indeed, since we don’t know how souls are supposed to work, souls would not help to explain these capacities). Rather, these are the sorts of cognitive capacities that psychologists and neuroscientists are well positioned to study.

    This conception of free will represents a longstanding and dominant view in philosophy, though it is typically ignored by scientists who conclude that free will is an illusion. It also turns out that most non-philosophers have intuitions about free and responsible action that track this conception of free will. Researchers in the new field of experimental philosophy study what “the folk” think about philosophical issues and why. For instance, my collaborators and I have found that most people think that free will and responsibility are compatible with determinism, the thesis that all events are part of a law-like chain of events such that earlier events necessitate later events.[3] That is, most people judge that you can have free will and be responsible for your actions even if all of your decisions and actions are entirely caused by earlier events in accord with natural laws.

    Our studies suggest that people sometimes misunderstand determinism to mean that we are somehow cut out of this causal chain leading to our actions. People are threatened by a possibility I call “bypassing” — the idea that our actions are caused in ways that bypass our conscious deliberations and decisions. So, if people mistakenly take causal determinism to mean that everything that happens is inevitable no matter what you think or try to do, then they conclude that we have no free will. Or if determinism is presented in a way that suggests all our decisions are just chemical reactions, they take that to mean that our conscious thinking is bypassed in such a way that we lack free will.

    Even if neuroscience and psychology were in a position to establish the truth of determinism — a job better left for physics — this would not establish bypassing. As long as people understand that discoveries about how our brains work do not mean that what we think or try to do makes no difference to what happens, then their belief in free will is preserved. What matters to people is that we have the capacities for conscious deliberation and self-control that I’ve suggested we identify with free will.

    But what about neuroscientific evidence that seems to suggest that these capacities are cut out of the causal chains leading to our decisions and actions? For instance, doesn’t neuroscience show that our brains make decisions before we are conscious of them such that our conscious decisions are bypassed? With these questions, we can move past the debates about whether free will requires souls or indeterminism — debates that neuroscience does not settle — and examine actual neuroscientific evidence. Consider, for instance, research by neuroscientists suggesting that non-conscious processes in our brain cause our actions, while conscious awareness of what we are doing occurs later, too late to influence our behavior. Some interpret this research as showing that consciousness is merely an observer of the output of non-conscious mechanisms. Extending the paradigm developed by Benjamin Libet, John-Dylan Haynes and his collaborators used fMRI research to find patterns of neural activity in people’s brains that correlated with their decision to press either a right or left button up to seven seconds before they were aware of deciding which button to press. Haynes concludes: “How can I call a will ‘mine’ if I don’t even know when it occurred and what it has decided to do?”

    However, the existing evidence does not support the conclusion that free will is an illusion. First of all, it does not show that a decision has been made before people are aware of having made it. It simply finds discernible patterns of neural activity that precede decisions. If we assume that conscious decisions have neural correlates, then we should expect to find early signs of those correlates “ramping up” to the moment of consciousness. It would be miraculous if the brain did nothing at all until the moment when people became aware of a decision to move. These experiments all involve quick, repetitive decisions, and people are told not to plan their decisions but just to wait for an urge to come upon them. The early neural activity measured in the experiments likely represents these urges or other preparations for movement that precede conscious awareness.

    This is what we should expect with simple decisions. Indeed, we are lucky that conscious thinking plays little or no role in quick or habitual decisions and actions. If we had to consciously consider our every move, we’d be bumbling fools. We’d be like perpetual beginners at tennis, overthinking every stroke. We’d be unable to speak fluently, much less dance or drive. Often we initially attend consciously to what we are doing precisely to reach the point where we act without consciously attending to the component decisions and actions in our complex endeavors. When we type, tango, or talk, we don’t want conscious thinking to precede every move we make, though we do want to be aware of what we’re doing and correct any mistakes we’re making. Conscious attention is relatively slow and effortful. We must use it wisely.

    We need conscious deliberation to make a difference when it matters — when we have important decisions and plans to make. The evidence from neuroscience and psychology has not shown that consciousness doesn’t matter in those sorts of decisions — in fact, some evidence suggests the opposite. We should not begin by assuming that free will requires a conscious self that exists beyond the brain (where?), and then conclude that any evidence that shows brain processes precede action thereby demonstrates that consciousness is bypassed. Rather, we should consider the role of consciousness in action on the assumption that our conscious deliberation and rational thinking are carried out by complex brain processes, and then we can examine whether those very brain processes play a causal role in action.

    For example: suppose I am trying to decide whether to give $1,000 to charity or buy a new TV. I consciously consider the reasons for each choice — e.g., how it fits with my goals and values. I gather information about each option. Perhaps I struggle to overcome my more selfish motivations. I decide based on this conscious reasoning (it certainly would not help if I could magically decide on no basis at all), and I act accordingly. Now, let’s suppose each part of this process is carried out by processes in my brain. If so, then to show that consciousness is bypassed would require evidence showing that thosevery brain processes underlying my conscious reasoning are dead-ends. It would have to show that those brain processes do not connect up with the processes that lead to my typing my credit card number into the Best Buy Web site (I may then regret my selfish decision and re-evaluate my reasons for my future decisions).

    None of the evidence marshaled by neuroscientists and psychologists suggests that those neural processes involved in the conscious aspects of such complex, temporally extended decision-making are in fact causal dead ends. It would be almost unbelievable if such evidence turned up. It would mean that whatever processes in the brain are involved in conscious deliberation and self-control — and the substantial energy these processes use — were as useless as our appendix, that they evolved only to observe what we do after the fact, rather than to improve our decision-making and behavior. No doubt these conscious brain processes move too slowly to be involved in each finger flex as I type, but as long as they play their part in what I do down the road — such as considering what ideas to type up — then my conscious self is not a dead end, and it is a mistake to say my free will is bypassed by what my brain does.

    So, does neuroscience mean the death of free will? Well, it could if it somehow demonstrated that conscious deliberation and rational self-control did not really exist or that they worked in a sheltered corner of the brain that has no influence on our actions. But neither of these possibilities is likely. True, the mind sciences will continue to show that consciousness does not work in just the ways we thought, and they already suggest significant limitations on the extent of our rationality, self-knowledge, and self-control. Such discoveries suggest that most of us possess less free will than we tend to think, and they may inform debates about our degrees of responsibility. But they do not show that free will is an illusion.

    If we put aside the misleading idea that free will depends on supernatural souls rather than our quite miraculous brains, and if we put aside the mistaken idea that our conscious thinking matters most in the milliseconds before movement, then neuroscience does not kill free will. Rather, it can help to explain our capacities to control our actions in such a way that we are responsible for them. It can help us rediscover free will."----
  16. Magical Realist Valued Senior Member

    Actually determinism "is the philosophical position that for every event, including human action, exist conditions that could cause no other event."-- This contradicts probablism, which entails that with every event exist conditions that could cause any among several possible events. With determinism you have no possibility of alternative outcomes. With probability you DO have the possibility of alternative outcomes. The two concepts are mutually exclusive.
  17. Sarkus Hippomonstrosesquippedalo phobe Valued Senior Member

    "Random number generators" involving pi, or any such seed number, are pseudo-random only? Yes, they provide numbers statistically similar to true randomness, but they are not truly random. I would suggest you do a simple read of what wiki has to say on the matter.

    But let's see what David H Bailey has to say on it... You, know, the guy whose editorial of his work by the BBC you posted...
    Ah, yes:
    "To begin with, we have to be careful what we mean by 'random'. Clearly pi is not 'random' in the strict sense, because individual digits are certainly not random but mathematically fixed."
    - Huffington Post article by David H Bailey and Jonathan M Borwein

    Do you need that explained to you in more detail?

    And no, the sequence of digits in pi is not chaotic, because it is not in and of itself a system, so I am struggling to understand your assertion here. If you mean that the system of trying to use previous numbers to predict the next is a chaotic system, please provide support for it. But please note that just because people found a link between the fields of chaotic dynamics and "normal" numbers does not mean that the sequence of digits in normal numbers are necessarily chaotic.
  18. Magical Realist Valued Senior Member

    Pi itself isn't random since it is obviously a mathematically fixed number. But the sequencing of pi digits IS random and unpredictable and chaotic. An important distinction that you yourself quoted:"at the very least we have shown why the digits of pi and log(2) appear to be random: because they are closely approximated by a type of generator associated with the field of chaotic dynamics." Do you require more citations for this fact than those I've already given? Here's another one:
  19. Yazata Valued Senior Member

    Certainly the laws of physics constrain the range of physically possible choices available to me. I can't suddenly choose to jump over the Moon. We can all agree about that.

    But seemingly I can still choose whether or not to jump. It still seems that I do so because I will to do so.

    The word 'will' typically refers to the mental faculty that is responsible for acts of volition such as choosing, deciding and initiating intentional bodily movements.

    So, maybe the free-will/determinism argument comes down, at least in part, to whether physics (or some other science) denies the reality of the human will. That seems to be a big part of it. There seems to be the idea that it's all just an "illusion", that physical causality discredits the idea that the human will initiates acts of seeming volition, and that those events were instead already predetermined by the state of the universe and the inexorable laws of physics long beforehand.

    Of course acts of will are generally thought to be intentional actions. They aren't just random tosses of the dice. So it would be false to imagine human action as being unrelated to anything else. Obviously it's closely associated with our purposes, our understanding of the situation we are in, our knowledge base, our emotional state, and all kinds of things like that.

    That's basically what "free-will" means, most of the time the phrase is used. It means that our acts of will, our choices and decisions, are the result of our own intentions, not somebody else's. The choices we reach weren't imposed on us coercively by some outside force. They arose in our own minds, out of our own understanding and desires.

    If we assume a physicalist stance (as I do) and if we basically reduce our psychologistic concepts to events occuring in the underlying neurophysiology (as I'm inclined to try to do), then the idea of acts of will arising from our prexisting intentions, desires and understanding may all receive causal interpretations, without doing any real damage to the free-will idea. We aren't denying that our own knowledge and intentions shape the decision processes that arise from them, we are just giving a causal account of how that happens.

    It doesn't even mean that some modest determinism is inconsistent with our intuitions of free-will. Our wills do seem to be determined to some large extent by our desires and by our understanding of the situations we find ourselves in. Nobody needs to deny that, and probably shouldn't if we want to make sense of human behavior. And our internal states, and the external states that surround us, don't arise from nowhere.

    What I'm suggesting is that the free-will intuition isn't really inconsistent with causality and even with determinism, provided that they remain temporally local, restricted to short time scales. Everyone agrees that free actions arise from the actor's own understanding, intentions and will. Our understanding and intentions are in turn shaped by our previous life histories.

    What does seem to do violence to the free-will intuition is the strong-determinististic speculation that all of this stuff was already fully predetermined in all of its specifics long before any of it happens. The state of the universe at time A fully determines the state of the universe at time B, the state of the universe at time B fully determines its state at time C, and so on. So in this vision, the state of the universe at time A has already determined everything that's going to happen all the way out to time Z, such that any idea we might have that a particular organisms' own internal real-time cognitive processes are what's guiding the organism's behavior is merely an illusion. Everything it does was all fated to happen precisely that way at the very beginning. That's where any (presumably divine) free choice that might have occurred was actually made, back at creation, when the laws of physics were enacted and the universe's initial conditions specified. Everything else follows inexorably from that.

    The idea of probabilistic causality seems to me like it might be a way to avoid that strong-deterministic conclusion, without denying causality and even determinism entirely. It allows us to continue saying that event A causes event B causes event C... Every event has a preceding cause. But event A might not totally determine event B, there might be some unpredictability in what happens. As the universe evolves and events proliferate, small indeterminacies multiply into big ones, eventually to the point where more temporally distant states of affairs can't be said to have been determined by early ones at all, even if continuous chains of probabilistic causation still link them. The universe's timeline might prenetrate into possibility-space in a fundamentally unpredictable way. There will still be causal chains determining things, but for highly complex systems the temporal range of exact determinism might be relatively short, getting fuzzier as timescales expand.

    So, if an organism in this less rigidly deterministic kind of ontological environment still wants to behave appropriately in whatever situation it finds itself in, pursuing food, avoiding predators, or making it through another day of work, it's own internal onboard data-processor, however neurophysiological, causal and even deterministic it might be, is still going to have to size up the surrounding situation in the light of the knowledge it's acquired, factor in its own goals and purposes, decide on and then initiate a course of action, making continuous mid-course corrections as events require. What's happening inside that organism's head still matters. It will still seem to possess what we think of as a will, will display volition and will essentially be steering itself.

    That's what free-will means to me.
    Last edited: Mar 5, 2014
  20. Sarkus Hippomonstrosesquippedalo phobe Valued Senior Member

    I know what determinism is, and what you have posted in no way contradicts or corrects anything I have said on the matter.
    I have also never said that they determinism and probabilistic determinism were not mutually exclusive, and have repeatedly told you that probabilistic determinism is inherently indeterministic.
    Why do you keep ignoring what I have repeatedly told you?

    I admit that having "determinism" in the name of the philosophy of probabilistic determinism can be confusing for some, but it is a recognised label.

    So let me rephrase:
    Determinism: same inputs always lead to exactly the same output (A leads to B)
    Probabilistic determinism: same inputs always lead to exactly the same probability function (A leads to f(B)).
    It is labelled with the name "determinism" because doing so stresses that the output is always the same probability function, rather than different ones.
    And yes, a probability function results in one of many possible outcomes, and is thus inherently indeterministic.
    As already explained time and time again.

    It is as though you respond to posts in near isolation from what has gone before.
  21. Magical Realist Valued Senior Member


    QQ: Probabilistic Determinism is about as contradictory as anything else.

    Sarkus:No it's not.

    You're confusing output with probability function. Those are not the same thing. Here's what probabilistic indeterminism really should say: same inputs lead to different outputs. There is iow no inevitability in probabilistic indeterminism as there is in determinism. One among several outputs is always possible, unlike determinism where only one output is possible. Sinking in yet?

    Sounds like you're asserting the very thing you criticized QQ for saying: indeterminate determinism? I have no problem with such paralogical terms. But don't complain about people using it when you yourself are positing the exact same thing.
  22. Sarkus Hippomonstrosesquippedalo phobe Valued Senior Member

    It's what it means to me as well, from a practical point of view. It is the way I perceive freewill, and I would assume it is how everyone consciously perceives it.

    If I may be so bold, your position is almost: "well, if it is an illusion, in the strict sense that what we perceive is not what is going on, but we have no means of perceiving it any other way than we do... then so what?"
    Is this correct as a summary?

    You don't deny the possibility of it being an illusion. But you also accept that freewill only means something to you in the way it is perceived, and that outside of that realm it is actually irrelevant.

    And I don't agree on a practical level.
    But we differ in that I like to understand what is going on behinds the scenes, so to speak, even if we can do nothing about it.
    Some people like to see how a film is made, but it doesn't detract from their enjoyment of the film, and they may even enjoy nuances that they hadn't appreciated before.
  23. Magical Realist Valued Senior Member

    Then you should acknowledge that the view behind the scenes in fact confirms that decision-making is having a real causal influence on our motor actions. Brain scans do not show decision-making occurring off to itself in the imagination parts of the brain. It is a causally linked process that can be followed to real effects in the motor areas of the brain. If decision-making were an illusion this causal linkage would not exist. We'd see other things causing the motor actions besides decision-making. And we just don't see that:

    "Our brains appear wired in ways that enable us, often unconsciously, to make the best decisions possible with the information we’re given. In simplest terms, the process is organized like a court trial. Sights, sounds, and other sensory evidence are entered and registered in sensory circuits in the brain. Other brain cells act as the brain’s “jury,” compiling and weighing each piece of evidence. When the accumulated evidence reaches a critical threshold, a judgment — a decision — is made.

    Where these judgments are made in the brain differs depending on the type of decision. For example, by studying stroke patients, researchers found that different parts of the frontal lobe, an area involved in planning and reasoning, are important in abstract and concrete decisions. People with stroke damage in the front of this brain region had trouble with abstract decisions, such as deciding to wash dishes, whereas people with damage in the back had trouble with concrete decisions, like the selection of physical movements during dishwashing. Other researchers studying monkeys found that decisions based on visual information rely on the parietal lobe, which integrates evidence supplied by the senses.

    In these different brain regions, research shows that decisions result from rapid and complex probability calculations in brain cells called neurons. In one study, monkeys played a video game that required them to determine which of two possible directions a moving display of random dots was headed. If a monkey guessed the direction correctly — by gazing at one of the two targets — it received a reward. As the monkey made its decisions, researchers recorded the electrical activity of neurons in the parietal lobe, and found that it closely correlated with the monkey’s decisions. In fact, the researchers could predict the monkey’s choices based solely on brain cell activity.

    Neuronal activity in the parietal lobe not only accurately predicted the monkey’s choice, but also the certainty with which the decision was made. In addition to trying to select the correct target for a big reward, the monkeys were able to choose a fixed target, which guaranteed a smaller, less desirable reward. When the monkey lacked confidence in its target selection, it chose the sure bet, and the brain cell activity in its parietal lobe changed, suggesting these cells also indicate the monkey’s confidence level."---

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