Tuesday, 23 September 2014

Neuroscience does not threaten people's sense of free will

A key finding from neuroscience research over the last few decades is that non-conscious preparatory brain activity appears to precede the subjective feeling of making a decision. Some neuroscientists, like Sam Harris, have argued that this shows our sense of free will is an illusion, and that lay people would realize this too if they were given a vivid demonstration of the implications of the science (see below). Books have even started to appear with titles like My Brain Made Me Do It: The Rise of Neuroscience and the Threat to Moral Responsibility by Eliezer J. Sternberg.

However, in a new paper, Eddy Nahmias, Jason Shepard and Shane Reuter counter such claims. They believe that Harris and others (who they dub "willusionists") make several unfounded assumptions about the foundations of most people's sense of free will. Using a series of vivid hypothetical scenarios based on Harris’ own writings, Nahmias and his colleagues tested whether people's belief in free will really is challenged by "neuroprediction" - the idea of neuroscientists using brain activity to predict a person's choices, and by the related notion that mental activity is no more than brain activity.

The research involved hundreds of undergrads at Georgia State University in Atlanta. They were told about a piece of wearable brain imaging technology - a cap - available in the future that would allow neuroscientists to predict a person's decisions before they made them. They also read a story about a woman named Jill who wore the cap for a month, and how scientists predicted her every choice, including her votes in elections.

Most of the students (80 per cent) agreed that this future technology was plausible, but they didn't think it undermined Jill's free will. Most of them only felt her free will was threatened if they were told that the neuroscientists manipulated Jill's brain activity to alter her decisions. Similar results were found in a follow-up study in which the scenario descriptions made clear that "all human mental activity just is brain activity", and in another that swapped the power of brain imaging technology for the mind reading skills of a psychic. In each case, students only felt that free will was threatened if Jill's decisions were manipulated, not if they were merely predicted via her brain activity or via her mind and soul (by the psychic).

Nahmias et al said their results showed that most people have a "theory-lite" view of free will - they aren't bothered by claims about mental activity being reduced to neural activity, nor by the idea that such activity precedes conscious decision-making and is readable by scientists. "Most people recognise that just because 'my brain made me do it,' that does not mean that I didn't do it of my own free will," the researchers said.

As neuroscience evidence increasingly enters the courtroom, the findings have important implications for understanding how such evidence might influence legal verdicts about culpability. An obvious limitation of the research is its dependence on students in Atlanta. It will be interesting to see if the same findings apply in other cultures.

_________________________________ ResearchBlogging.org

Nahmias, E., Shepard, J., & Reuter, S. (2014). It’s OK if ‘my brain made me do it’: People’s intuitions about free will and neuroscientific prediction Cognition, 133 (2), 502-516 DOI: 10.1016/j.cognition.2014.07.009

Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.


Research Digest said...

neuroscience just threatens itself with its addiction to mechanistic models and its insistence than meat makes consciousness ...

Research Digest said...

I have a numerous expirience in taking the LSD. Even more I've tried to write down, track all my trips on the paper. I've succeded. And I'm planning to share my thoughts on my personal blog here

Research Digest said...

I've read Mind Control by Jose Delgado and now I'm sure the "free will" is not more than a sense, subjective feeling

Research Digest said...

And physics does not threaten the belief in unicorns. So what, does that mean that unicorns exist?

Research Digest said...

Hi Christian (if I may),

I really appreciate your excellent coverage of our article. I really mean this. I very much appreciate the coverage, and I very much appreciate the quality of the coverage you are providing (both here and at WIRED). But there is one small--but very important, at least to me--detail to which I was hoping I could draw your attention.

In your article, you use the phrase "a team led by Eddy Nahmias," but this phrasing is a bit misleading. Eddy Nahmias and I were joint first authors. Our contributions are noted as being equal on the article . To be fair, it is easy to miss the "contribution equal" note on the article, as it inconspicuously marked with a superscript 1 next to our affiliations without clear indication what that '1' designates (unless one clicks on the '1'). I also realize that joint first authorships aren't super common, so it's not something you would normally be looking out for. Related, Shane Reuter was also an integral part of this project. Many times the "and team," "et al., " or "and colleagues" are graduate students or post-docs that could benefit tremendously from the exposure. And, in this case, one of us was actually an equal contributor.

Research Digest said...

hi Jason, thanks for getting in touch. Hopefully fixed here and over at WIRED - I've added a mention of all three of you in the second paragraph. Great study!

Research Digest said...

You are amazing! ... but "Shepard." Thanks, again!

Research Digest said...

gah ... sorry ... all done now (hopefully!)

Research Digest said...

Hi Jason, If what led the team was brain activity prior to decisions, how could you be joint first authors? Whose brain activity initiated the

I am joking; what I want to emphasize is something else: your "findings" were well known to the sages of old, who were aware that the feeling that there is a thinker is a result of the process of thinking. In the words of Heraclitus (fr. 2 DK):

"Though the logos is common, each individual believes he or she has a separate, particular and private intellect."

What Heraclitus was saying is that an individual’s awareness, intelligence, creativity and motility, rather than being functions of an inherently separate, autonomous psyche or soul, are in truth functions of the (universal) logos that constitutes the Gnitive (or “spiritual”) aspect of the physis and that is the common source and nature of all intellects—the illusory, apparently
separate intellect in question thus (being) no more than a false appearance that deluded humans mistakenly take for the core of their selves, and,
often, for an “immortal” soul. Thus, as Georg Christoph Lichtenberg—the idiosyncratic German reader of David Hume—made it clear, we are not the thinkers of thought (adapted from Lichtenberg, 1995, section “Causes,” p.
214, and Koyré, 1973, p. 17):

“[It would be better to use an impersonal formula and, rather than saying I think,] to say ‘there is thinking,’ just as one says ‘there is lightening’.”

Mexican poet Octavio Paz (1978, p. 44) was even more eloquent in this regard when he wrote, “…las voces que me piensan al pensarlas. Soy la sombra que arrojan mis palabras…” (“…the thoughts that think me as I think them; I am the shadow cast by my words…”).

At any rate, this should not be used to elude personal responsibility. This is the reason why Buddhists say that although there is no real agent of action, it is the same mental stream that experiences the effects of actions according to the law of karma.

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