In "True Lies" (ABA Journal "Law News Now", October 2009 issue), Mark Hansen reports
on a controlled experiment that used neuroscience to determine in a simulation who was "telling the truth" and who was "lying." No surprise this might work in a controlled experiment, but applying it to the real world courtroom poses serious challenges. A key problem is that unless you already know for sure what happened, you don't even know what evidence you should be asking about.
Also, in real life, false positives would be common for other reasons, for example:
The fact that somebody “recognizes” something doesn’t necessarily mean he’s guilty of anything, they point out.
“Just because you recognize Osama bin Laden doesn’t mean you spent time in an al-Qaida training camp with him,” Greely says. “Maybe you just saw his picture on TV or the cover of a magazine.”
Not only that, but some people might be secretly obsessed with bin Laden, and unwilling to admit it. They might have a high level of knowledge and interest in his activities without ever having met him or played a role in the activities. Some of those people might delude themselves that they did. So they falsely confess.
By the same token, he adds, a suspect might recognize a crime scene because he committed the crime in question or because the crime took place at a Starbucks, the inside of which all tend to look alike.
The EEG-based approach also appears to misunderstand the nature of memory, which does not record and recall information like a videotape recorder but changes and adapts over time, other experts caution.
.“Every time a memory is recalled, it is altered,” says University of Akron law professor Jane Moriarty, an expert on scientific evidence.
Experts also say the credibility of this line of research has been undercut somewhat by the hype given to it by Lawrence Farwell, one of its leading proponents.
Neuroscience risks disrepute due to hype about its potential in areas for which it was never designed.
A lawyer friend who addresses serious violence cases pointed out to me recently that, not only is it not always clear what the accused/convicted was thinking at the time of the offence, it is not always clear whether he even was
thinking much. If he is a drug addict or serious alcoholic, a blood sample might be more useful than a neuroscience scan for figuring out his probable state of mind (or lack thereof) at the time. He may not remember what he did accurately, which doesn't mean he didn't do it or wouldn't do it again.
If the accused has a mental disorder or is developmentally delayed, neuroscience might help determine whether he is fit to stand trial. But that is medicine, whose results may assist law. I think neuroscience is best to stay close to medicine.Hat tip:
Stephanie West Allen at Brains on Purpose