Determined, page 4
Can you decide to decide? Are intending and having an intent the same thing? Libet instructed subjects to note the time when they first became aware of “the subjective experience of ‘wanting’ or intending to act”—but are “wanting” and “intending” the same? Is it possible to be spontaneous when you’ve been told to be spontaneous?
As long as we’re at it, what actually is a readiness potential? Remarkably, nearly forty years after Libet, a paper can still be entitled “What Is the Readiness Potential?” Could it be deciding-to-do, actual “intention,” while the conscious sense of decision is deciding-to-do-now, an “implementation of intention”? Maybe the readiness potential doesn’t mean anything—some models suggest that it is just the point where random activity in the SMA passes a detectable threshold. Mele forcefully suggests that the readiness potential is not a decision but an urge, and physicist Susan Pockett and psychologist Suzanne Purdy, both of the University of Auckland, have shown that the readiness potential is less consistent and shorter when subjects are planning to identify when they made a decision, versus when they felt an urge. For others, the readiness potential is the process leading to deciding, not the decision itself. One clever experiment supports this interpretation. In it, subjects were presented four random letters and then instructed to choose one in their minds; sometimes they were then signaled to press a button corresponding to that letter, sometimes not—thus, the same decision-making process occurred in both scenarios, but only one actually produced movement. Crucially, a similar readiness potential occurred in both cases, suggesting, in the words of compatibilist neuroscientist Michael Gazzaniga, that rather than the SMA deciding to enact a movement, it’s “warming up for its participation in the dynamic events.”[20]
So are readiness potentials and their precursors decisions or urges? A decision is a decision, but an urge is just an increased likelihood of a decision. Does a preconscious signal like a readiness potential ever occur and despite that, the movement doesn’t then happen? Does a movement ever occur without a preconscious signal preceding it? Combining these two questions, how accurately do these preconscious signals predict actual behavior? Something close to 100 percent accuracy would be a major blow to free-will belief. In contrast, the closer accuracy is to chance (i.e., 50 percent), the less likely it is that the brain “decides” anything before we feel a sense of choosing.
As it turns out, predictability isn’t all that great. The original Libet study was done in such a way that it wasn’t possible to generate a number for this. However, in the Haynes studies, fMRI images predicted which behavior occurred with only about 60 percent accuracy, almost at the chance level. For Mele, a “60-percent accuracy rate in predicting which button a participant will press next doesn’t seem to be much of a threat to free will.” In Roskies’s words, “All it suggests is that there are some physical factors that influence decision-making.” The Fried studies recording from individual neurons pushed accuracy up into the 80 percent range; while certainly better than chance, this sure doesn’t constitute a nail in free will’s coffin.[21]
Now for the next criticisms.
What Is Consciousness?
Giving this section this ridiculous heading reflects how unenthused I am about having to write this next stretch. I don’t understand what consciousness is, can’t define it. I can’t understand philosophers’ writing about it. Or neuroscientists’, for that matter, unless it’s “consciousness” in the boring neurological sense, like not experiencing consciousness because you’re in a coma.[*],[22]
Nevertheless, consciousness is central to Libet debates, sometimes, in a fairly heavy-handed way. For example, take Mele, in a book whose title trumpets that he’s not pulling any punches—Free: Why Science Hasn’t Disproved Free Will. In its first paragraph, he writes, “There are two main scientific arguments today against the existence of free will.” One arises from social psychologists showing that behavior can be manipulated by factors that we’re not aware of—we’ve seen examples of these. The other is neuroscientists whose “basic claim is that all our decisions are made unconsciously and therefore not freely” (my italics). In other words, that consciousness is just an epiphenomenon, an illusory, reconstructive sense of control irrelevant to our actual behavior. This strikes me as an overly dogmatic way of representing just one of many styles of neuroscientific thought on the subject.
The “ooh, you neuroscientists not only eat your dead but also believe all our decisions are unconscious” nyah-nyah matters, because we shouldn’t be held morally responsible for our unconscious behaviors (although neuroscientist Michael Shadlen of Columbia University, whose excellent research has informed free-will debates, makes a spirited argument along with Roskies that we should be held morally responsible for even our unconscious acts).[23]
Compatibilists trying to fend off the Libetians often make a last stand with consciousness: Okay, okay, suppose that Libet, Haynes, Fried, and so on really have shown that the brain decides something before we have a sense of having consciously and freely done so. Let’s grant the incompatibilists that. But does turning that preconscious decision into actual behavior require that conscious sense of agency? Because if it does, rather than bypassing consciousness as an irrelevancy, free will can’t be ruled out.[*]
As we saw, knowing what a brain’s preconscious decision was moderately predicts whether the behavior will actually occur. But what about the relationship between the preconscious brain’s decision and the sense of conscious agency—is there ever a readiness potential followed by a behavior without a conscious sense of agency coming in between? One cool study done by Dartmouth neuroscientist Thalia Wheatley and collaborators[*] shows precisely this—subjects were hypnotized and implanted with a posthypnotic suggestibility that they make a spontaneous Libet-like movement. In this case, when triggered by the cued suggestion, there’d be a readiness potential and the subsequent movement, without conscious awareness in between. Consciousness is an irrelevant hiccup.[24]
Sure, retort compatibilists, this doesn’t mean that intentional behavior always bypasses consciousness—rejecting free will based on what happens in the posthypnotic brain is kind of flimsy. And there is a higher-order level to this issue, something emphasized by incompatibilist philosopher Gregg Caruso of the State University of New York—you’re playing soccer, you have the ball, and you consciously decide that you are going to try to get past this defender, rather than pass the ball off. In the process of then trying to do this, you make a variety of procedural movements that you’re not consciously choosing; what does it mean that you have made the explicit choice to let a particular implicit process take over? The debate continues, not just over whether the preconscious requires consciousness as a mediating factor but also over whether both can simultaneously cause a behavior.[25]
Amid these arcana, it’s hugely important if the preconscious decision requires consciousness as a mediator. Why? Because during that moment of conscious mediation we should then be expected to be able to veto a decision, prevent it from happening. And you can hang moral responsibility on that.[26]
Free Won’t: The Power to Veto
Even if we don’t have free will, do we have free won’t, the ability to slam our foot on the brake between the moment of that conscious sense of freely choosing to do something and the behavior itself? This is what Libet concluded from his studies. Clearly we have that veto power. Writ small, you’re about to reach for more M&M’s but stop an instant before. Writ larger, you’re about to say something hugely inappropriate and disinhibited but, thank God, you stop yourself as your larynx warms up to doom you.
The basic Libetian findings gave rise to a variety of studies looking at where vetoing actions fits in. Do it or not: once that conscious sense of intent occurs, subjects have the option to stop. Do it now or in a bit: once that conscious sense of intent occurs, immediately push the button or first count to ten. Impose an external veto: In a brain-computer interface study, researchers used a machine learning algorithm that monitored a subject’s readiness potential, predicting in real time when the person was about to move; some of the time, the computer would signal the subject to stop the movement in time. Of course, people could generally stop themselves up until a point of no return, which roughly corresponded to when the neurons that send a command directly to muscles were about to fire. As such, a readiness potential doesn’t constitute an unstoppable decision, and one would generally look the same whether the subject was definitely going to push a button or there was the possibility of a veto.[*],[27]
How does the vetoing work, neurobiologically? Slamming a foot on the brake involved activating neurons just upstream of the SMA.[*] Libet may have spotted this in a follow-up study examining free won’t. Once subjects had that conscious sense of intent, they were supposed to veto the action; at that point, the tail end of the readiness potential would lose steam, flatten out.[*],[28]
Meanwhile, other studies explored interesting spin-offs of free won’t–ness. What’s the neurobiology of a gambler on a losing streak who manages to stop gambling, versus one who doesn’t?[*] What happens to free won’t when there’s alcohol on board? How about kids versus adults? It turns out that kids need to activate more of their frontal cortex than do adults to get the same effectiveness at inhibiting an action.[29]
So what do all these versions of vetoing a behavior in a fraction of a second say about free will? Depends on whom you talk to, naturally. Findings like these have supported a two-stage model about how we are supposedly the captains of our fate, one espoused by the likes of everyone from William James to many contemporary compatibilists. Stage one, the “free” part: your brain spontaneously chooses, amid alternative possibilities, to generate the proclivity toward some action. Stage two, the “will” part, is where you consciously consider this proclivity and either green-light it or free-won’t it. As one proponent writes, “Freedom arises from the creative and indeterministic generation of alternative possibilities, which present themselves to the will for evaluation and selection.” Or in Mele’s words, “even if urges to press are determined by unconscious brain activity, it may be up to the participants whether they act on those urges or not.”[30] Thus, “our brains” generate a suggestion, and “we” then judge it; this dualism sets our thinking back centuries.
The alternative conclusion is that free won’t is just as suspect as free will, and for the same reasons. Inhibiting a behavior doesn’t have fancier neurobiological properties than activating a behavior, and brain circuitry even uses their components interchangeably. For example, sometimes brains do something by activating neuron X, sometimes by inhibiting the neuron that is inhibiting neuron X. Calling the former “free will” and calling the latter “free won’t” are equally untenable. This recalls chapter 1’s challenge to find a neuron that initiated some act without being influenced by any other neuron or by any prior biological event. Now the challenge is to find a neuron that was equally autonomous in preventing an act. Neither free-will nor free-won’t neurons exist.
* * *
• • •
Having now reviewed these debates, what can we conclude? For Libetians, these studies show that our brains decide to carry out a behavior before we think that we’ve freely and consciously done so. But given the criticisms that have been raised, I think all that can be concluded is that in some fairly artificial circumstances, certain measures of brain function are moderately predictive of a subsequent behavior. Free will, I believe, survives Libetianism. And yet I think that is irrelevant.
Just in Case You Thought This Was All Academic
The debates over Libet and his descendants can be boiled down to a question of intent: When we consciously decide that we intend to do something, has the nervous system already started to act upon that intent, and what does it mean if it has?
A related question is screamingly important in one of the areas where this free-will hubbub is profoundly consequential—in the courtroom. When someone acts in a criminal manner, did they intend to?
By this I’m not suggesting bewigged judges arguing about some lowlife’s readiness potentials. Instead, the questions that define “intent” are whether a defendant could foresee, without substantial doubt, what was going to happen as a result of their action or inaction, and whether they were okay with that outcome. From that perspective, unless there was intent in that sense, a person shouldn’t be convicted of a crime.
Naturally, this generates complex questions. For example, should intending to shoot someone but missing count as a lesser crime than shooting successfully? Should driving with a blood alcohol level in the range that impairs control of a car count as less of a transgression if you lucked out and happened not to kill a pedestrian than if you did (an issue that Oxford philosopher Neil Levy has explored with the concept of “moral luck”)?[31]
As another wrinkle, the legal field distinguishes between general and specific intent. The former is about intending to commit a crime, whereas the latter is intending to commit a crime as well as intending a specific consequence; the charge of the latter is definitely more serious than the former.
Another issue that can come up is deciding whether someone acted intentionally out of fear or anger, with fear (especially when reasonable) seen as more mitigating; trust me, if the jury consisted of neuroscientists, they’d deliberate for eternity trying to decide which emotion was going on. How about if someone intended to do something criminal but instead unintentionally did something else criminal?
An issue that we all recognize is how long before a behavior the intent was formed. This is the world of premeditation, the difference between, say, a crime of passion with a few milliseconds of intent versus an action long planned. It is pretty unclear legally exactly how long one needs to meditate upon an intended act for it to count as premeditated. As an example of this lack of clarity, I once was a teaching witness in a trial where a pivotal issue was whether eight seconds (as recorded by a CCTV camera) is enough time for someone in a life-threatening circumstance to premeditate a murder. (My two cents was that under the circumstances involved, eight seconds not only wasn’t enough time for a brain to do premeditated thinking, it wasn’t enough time for it to do any thinking, and free won’t–ness was an irrelevant concept; the jury heartily disagreed.)
Then there are questions that can be at the core of war crime trials. What kind of threat is needed for someone’s criminality to count as coerced? What about agreeing to do something with criminal intent while knowing that if you refused, someone else would do it immediately and more brutally? Taking things even further, what should be done with someone who intentionally chose to commit a crime, not knowing that they would have been forced to commit that act if they had tried to do otherwise?[*],[32]
At this juncture, we appear to have two wildly different realms of thinking about agency and responsibility—people arguing about the supplementary motor area in neurophilosophy conferences and prosecutors and public defenders jousting in courtrooms. Yet they share something that potentially strikes a blow against free-will skepticism:
Suppose it turns out that our sense of conscious decision-making doesn’t actually come after things like readiness potentials, that activity in the SMA, the prefrontal cortex, the parietal cortex, wherever, is never better than only moderately predicting behavior, and only for the likes of pushing buttons. You sure can’t say free will is dead based on that.
Likewise, suppose a defendant says, “I did it. I knew there were other things I could do, but I intended to do it, planned it in advance. I not only knew that X could have been the outcome, I wanted that to happen.” Good luck convincing someone that the defendant lacked free will.
But the point of this chapter is that even if either or both of these are the case, I still think that free will doesn’t exist. To appreciate why, time for a Libet-style thought experiment.
The Death of Free Will in the Shadow of Intent
You have a friend doing research for her doctorate in neurophilosophy, and she asks you to be a test subject. Sure. She’s upbeat because she’s figured out how to both get another data point for her study and simultaneously accomplish something else that she’s keen on—win-win. It involves ambulatory EEG, out of the lab, like in the bungee jumping study. You’re out there now, wired up with the leads, electromyography being done on your hand, a clock in view.
As with the classic Libet, the motoric action involved is to move your index finger. Hey, aren’t we decades past that sort of really artificial scenario? Fortunately, the study is more sophisticated than that, thanks to your friend’s careful experimental design—you’ll be making a simple movement, but with a nonsimple consequence. Don’t plan ahead to make this movement, you’re told, do it spontaneously, and note on the clock what time it is when you first consciously intend to. All set? Now, when you feel like it, pull a trigger and kill this person.
Maybe the person is an enemy of the Fatherland, a terrorist blowing up bridges in one of the gloriously occupied colonies. Maybe it’s the person behind the cash register in the liquor store you’re robbing. Maybe they’re a terminally ill loved one in unspeakable pain, begging you to do this. Maybe it’s someone who is about to harm a child; maybe it is the infant Hitler, cooing in his crib.
You are free to choose not to shoot. You’re disillusioned with the regime’s brutality and refuse; you think killing the clerk ups the ante too much if you’re caught; despite your loved one begging, you just can’t do it. Or maybe you’re Humphrey Bogart, your friend is Claude Rains, you’re confusing reality with story line and figure that if you let Major Strasser escape, the story doesn’t end and you’ll get to star in a sequel to Casablanca.[*]
