Thursday, March 3, 2011

Brain Scans as Evidence: Truths, Proofs, Lies, and Lessons

By Francis Shen & Owen Jones (H/T Neuroethics).

Interesting Excerpts:
In U.S. v. Semrau the government charged psychologist Dr. Lorne Semrau with Medicare/Medicaid fraud. Proving fraud requires proving that Semrau knowingly violated the law. And Semrau’s defense was built, in part, around brain scan results that allegedly demonstrated he was telling the truth when he claimed (some years after the fact) that even though he had mis-billed for services, he did not do so intending to defraud the government.
The central legal question in the case concerned Semrau’s mental state at the time of his acts: between 1999 and 2005, did Semrau “knowingly devise a scheme or artifice to defraud a health care benefit program in connection with the delivery of or payment for health care benefits, items, or services?”
In Laken’s own words: “What we can say is … that we believe his brain – he believes that he is telling the truth at least.”29 Verifying the truthfulness of a belief, of course, doesn’t provide the court with information on so-called “ground” truth, i.e. whether the belief is true to begin with. Rather, as Laken explained, “If [experimental subjects] say that this is the truth, then I believe them that this is the truth. At least that's what they are telling me is the truth. These are the truths of the statements.” (emphasis added).30 The truth of Semrau’s statements about mental states is, of course, distinct from the fact relevant to the case: Semrau’s actual mental states at the time of the billing.
Neuroscientist Nancy Kanwisher, for instance, argues that “making a false response when you are instructed to do so isn’t a lie, and it’s not deception. It’s simply doing what you are told. We could call it an ‘instructed falsehood.’” 54 And neuroscientist Kamila E. Sip and colleagues similarly argue that the “absence of this intentional aspect of deception in the experiments is … more than a mere experimental confound.”55 It fundamentally changes what the brain is being asked to do. Researchers, in this view, are indeed measuring something – but they are not necessarily measuring “lying”.
Using brain-based lie detection as an example, it has been noted that no laboratory study has been able to replicate the real-world, ecologically valid stakes (such as avoiding imprisonment) that often accompany lying.60 In Semrau, when Dr. Laken was asked on cross examination about ecological validity, he replied that “whether they're lying about biographical things, whether they're lying because they've been told a lie or not told a lie, whether they're lying about playing cards -- all of these things seem to be activating the same region. So it appears that irregardless of what type of lie, the same brain regions are out there.”61 This statement reflects an assumption that a lie – whether told in a scanner without consequence, or in the real world with great consequence – should be expected to activate the same brain regions. While theoretically plausible, there is no general acceptance of such an
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