Friday, March 30, 2012

Neuroscience, Prediction, and Free Will: Or, Ripping off The Adjustment Bureau

Imagine a world that is exactly like ours, except for one difference: There exist supernatural beings that have the ability to compute the outcomes of human decision making well in advance of any given decision being made. As matter of fact, they are able to predict with 100 percent accuracy what any given individual will do at any given moment for up to six months into the future. They are not super-psychics, per se. Rather these beings have complete access to information about an individual’s history and complete access to the physical state of the world (including the physical states of the individual’s nervous system). These beings can use this information to conduct computations that allow them to predict human decision making. Not only can these beings predict human decision making with pin-point accuracy, but they know exactly how to rearrange things so that you will end up making some decision x at some time t. In other words, if these beings felt so inclined, they could intervene on you or your world, and by intervening could get you to do what they wanted you to do. But they don’t feel so inclined. They are perfectly content with being able to simply watch and to know. They never actually intervene in the world; they never actually do anything to change the course of a single human decision. Question: In a world in which these supernatural beings exist (but never intervene), do people have free will?

Now imagine a world in which these supernatural beings exist, and they do intervene from time to time. They sometimes nudge the course of history; they like to keep people “on track.” Same question: In this world, do people have free will? By now, you have probably realized that the world so-described is a rip off of the book and movie The Adjustment Bureau. And, if you are anything like David Norris (Matt Damon’s character in the movie), the fact that these beings can use in physical information to predict human decision making does not rock your belief in free will so much. For Norris, it is only when it is made known that these beings intervene on the world in order to manipulate human decision making does Norris ponder: “What about free will?” To which the beings respond roughly: The last time we tried free will, two world wars and nuclear conflict transpired. The time prior to that, something called the Dark Ages happened. 

But wait?! If some neuroscientists, biologists, and psychologists are correct, then in this Adjustment Bureau world, the super-natural beings’ response would be utterly nonsensical to us. Why? Well, these scientists claim that our everyday notion of free will is completely and fully incompatible with a world in which physical facts can be used to predict human decision making. [Don’t believe me? Well, some scientists (see here and here for just two examples ) are convinced that being able to use physical information from the brain to predict with 60 percent accuracy the outcome of a simple dichotomous choice 7 seconds prior to conscious awareness of the decision effectively undermines the existence of free will. 

From Fried et al (2011) Neuron

Why do they think that this undermines free will? 

Well, many scientists in this debate seem to think our everyday notion of free will requires non-physical causation or contra-causal agency or often both. These scientists take it that results like the one mentioned above undermine non-physical causation and contra-causal agency.] Of course, in the Adjustment Bureau-like world described above, supernatural beings can use physical facts to perfectly predict human decision making up until six months in advance (which would be impossible if there was non-physical causation or contra-causal agency). As such, if these scientists are right, then we should uncontrollably cringe at the suggestion that any person at any point in time in this Adjustment Bureau-like world ever even had an ounce of free will. But most of us don’t cringe at this suggestion; for most of us, the existence of free will in the Adjustment Bureau-like world is only fully challenged when it is discovered that these supernatural beings are using the available information to manipulate human decision making. 

So, what does this fantastic story tell us about neuroscience, prediction, and free will? Well, maybe nothing, but I think that the story at least suggest that prediction alone (even perfect prediction based on physical facts) does not undermine our everyday notion of free will. If this is right, if neuroscience is going to undermine our everyday notions of free will, neuroscience is not going achieve this feat simply by demonstrating that our minds are physical and that we can use physical information to predict what our minds will do.  

--Jason Shepard
Psychology Graduate Student, Neuroethics Scholars Program Fellow


Want to cite this post?
Shepard, J. (2012). Neuroscience, Prediction, and Free Will: Or, Ripping off The Adjustment Bureau. The Neuroethics Blog. Retrieved on , from http://www.theneuroethicsblog.com/2012/03/neuroscience-prediction-and-free-will.html

4 comments:

BubbaRich said...

I tend to agree, but I also think the practical unpredictability of brain states and actions is important in a deeper concept of free will.

Michael Arenson said...

Well-said! And a very interesting post. Thanks!

Riley Zeller-Townson said...

Very interesting. I might go so far as to guess that the reason intervention is the problem rather than prediction, is that prediction only implies we are deterministic systems (which I'm fine with being, beats being an absurd random number generator). However, intervention implies that the thing that is most responsible for my actions is not me, nor something so much larger than me that I can't comprehend what its 'will' might be (everything-but-me, General Observer Dude), but something that is close enough to my scale that it has a thing we could identify as 'will' that is acting in place of mine. Though I'm not so sure if that is to assert 'free will' as much as 'my will.'

Jason Shepard said...

@ BubbaRich: I like that you say that the practical unpredictability of brain states and actions is important in a deeper concept of free will. My question would be why is practical unpredictability important for this deeper concept of free will? Is it because predictability in practice by itself undermines this deeper notion of free will? Or is that predictability in practice undermines this deeper notion of free will because of the uneasiness associated with other things that may come along with predictability in practice (e.g., imagine a Minority Report-type situation or the increased ability of others to manipulate us)?

@Michael Arenson: Thank you for your kind words.

@Riley: Exactly! But many of the scientists entering into the neuroscience vs. free will debate assume that views like the one you put forward are not held by many of "the folk." But, of course, I think the folk actually do hold views that are much closer to what you are expressing than what some of the scientist assume the folk's views to be (and people's everyday reactions to fantastic stories like the Adjust Bureau gives us some evidence of the fact that people's everyday notion of free will is probably closer to the view you are putting forward).