Tuesday, September 2, 2008

Neural Priming--Does What You Think Affect Your Actions?

The whole concept of neural priming (aka subliminal priming) is fascinating! I first heard of it in Malcolm Gladwell's book Blink, which I highly highly recommend.


The basic idea is that what we see, read, hear, subconsciously effect our actions. The formal definition in one form is "Unconscious exposure to written words facilitates the subsequent conscious processing of the same stimuli, a behavioral phenomenon known as subliminal priming (1)."

Here is a great study done in conjunction with the University of Minnesota (go Gophers!!) here and an article written about it on Mind Matters. Very cool stuff!

References
1. Forster KI, Mohan K, Hector J (2003) in Masked Priming: State of the Art, eds
Kinoshita K, Lupker SJ (Psychology Press, Hove, UK), pp 3–37.

Free Will versus the Programmed Brain

If our actions are determined by prior events, then do we have a choice about anything—or any responsibility for what we do?

By Shaun Nichols

Many scientists and philosophers are convinced that free will doesn’t exist at all. According to these skeptics, everything that happens is determined by what happened before—our actions are inevitable consequences of the events leading up to the action—and this fact makes it impossible for anyone to do anything that is truly free. This kind of anti-free will stance stretches back to 18th century philosophy, but the idea has recently been getting much more exposure through popular science books and magazine articles. Should we worry? If people come to believe that they don’t have free will, what will the consequences be for moral responsibility?

In a clever new
study, psychologists Kathleen Vohs at the University of Minnesota and Jonathan Schooler at the University of California at Santa Barbara tested this question by giving participants passages from The Astonishing Hypothesis, a popular science book by Francis Crick, a biochemist and Nobel laureate (as co-discoverer, with James Watson, of the DNA double helix). Half of the participants got a passage saying that there is no such thing as free will. The passage begins as follows: “‘You,’ your joys and your sorrows, your memories and your ambitions, your sense of personal identity and free will, are in fact no more than the behavior of a vast assembly of nerve cells and their associated molecules. Who you are is nothing but a pack of neurons.”
The passage then goes on to talk about the neural basis of decisions and claims that “…although we appear to have free will, in fact, our choices have already been predetermined for us and we cannot change that.” The other participants got a passage that was similarly scientific-sounding, but it was about the importance of studying consciousness, with no mention of free will.

After reading the passages, all participants completed a survey on their belief in free will. Then comes the inspired part of the experiment. Participants were told to complete 20 arithmetic problems that would appear on the computer screen. But they were also told that when the question appeared, they needed to press the space bar, otherwise a computer glitch would make the answer appear on the screen, too. The participants were told that no one would know whether they pushed the space bar, but they were asked not to cheat.

The results were clear: those who read the anti-free will text cheated more often! (That is, they pressed the space bar less often than the other participants.) Moreover, the researchers found that the amount a participant cheated correlated with the extent to which they rejected free will in their survey responses.

Varieties of Immorality

Philosophers have
raised questions about some elements of the study. For one thing, the anti-free will text presents a bleak worldview, and that alone might lead one to cheat more in such a context (“OMG, if I’m just a pack of neurons, I have much bigger things to worry about than behaving on this experiment!”). It might be that one would also find increased cheating if you gave people a passage arguing that all sentient life will ultimately be destroyed in the heat death of the universe.

On the other hand, the results fit with what some
philosophers had predicted. The Western conception idea of free will seems bound up with our sense of moral responsibility, guilt for misdeeds and pride in accomplishment. We hold ourselves responsible precisely when we think that our actions come from free will. In this light, it’s not surprising that people behave less morally as they become skeptical of free will. Further, the Vohs and Schooler result fits with the idea that people will behave less responsibly if they regard their actions as beyond their control. If I think that there’s no point in trying to be good, then I’m less likely to try.

Even if giving up on free will does have these deleterious effects, one might wonder how far they go. One question is whether the effects extend across the moral domain. Cheating in a psychology experiment doesn’t seem too terrible. Presumably the experiment didn’t also lead to a rash of criminal activity among those who read the anti-free will passage. Our moral revulsion at killing and hurting others is likely too strong to be dismantled by reflections about determinism. It might well turn out that other kinds of immoral behavior, like cheating in school, would be affected by the rejection of free will, however.

Is the Effect Permanent?

Another question is how long-lived the effect is. The Vohs and Schooler study suggests that immediately after people are made skeptical of free will, they cheat more. But what would happen if those people were brought back to the lab two weeks later? We might find that they would continue to be skeptical of free will but they would no longer cheat more.

There is no direct evidence on this question, but there is recent evidence on a related issue. Philosopher Hagop Sarkissian of the City Univeristy of New York and colleagues had people from Hong Kong, India, Colombia and the U.S. complete a survey on determinism and moral responsibility. Determinism was described in nontechnical terms, and participants were asked (in effect): whether our universe was a deterministic universe and whether people in a deterministic universe are morally responsible for their actions.

Across cultures, they found that most people said that our universe is not deterministic and also that people in the deterministic universe are not responsible for their actions. Although that isn’t particularly surprising—people want to believe they have free will—something pretty interesting emerges when you look at the smaller group of people who say that our universe is deterministic. Across all of the cultures, this substantial minority of free will skeptics were also much more likely to say that people are responsible even if determinism is true. One way to interpret this finding is that if you come to believe in determinism, you won’t drop your moral attitudes. Rather, you’ll simply reverse your view that determinism rules out moral responsibility.

Many philosophers and scientists reject free will and, while there has been no systematic study of the matter, there’s currently little reason to think that the philosophers and scientists who reject free will are generally less morally upright than those who believe in it. But this raises yet another puzzling question about the belief in free will. People who explicitly deny free will often continue to hold themselves responsible for their actions and feel guilty for doing wrong. Have such people managed to accommodate the rest of their attitudes to their rejection of free will? Have they adjusted their notion of guilt and responsibility so that it really doesn’t depend on the existence of free will? Or is it that when they are in the thick of things, trying to decide what to do, trying to do the right thing, they just fall back into the belief that they do have free will after all?