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Archive for the ‘lie detection’ Category

OK, here we go again. Remember the fuzz about the Iacoboni lab at UCLA, where they used fMRI to probe into voters likes and dislikes of politicians? Now,a good article in the Atlantic.com gives us a 1st person story about the trip through the fMRI experiment, the thoughts and results following this scientific un-rigourous and invalid approach. Jeffrey Goldberg reports in a funny and entertaining manner how it all goes about.

As with the previously mentioned NY Times article by the Iacoboni team, Goldberg is scanned while watching different famous people, including politicians, actors and musicians. After a few days, the imaging results come in and are presented and discussed with Iacoboni. To me, the dialoguoes could be referring to tea-leaf reading, astrology or ___ (put in your preferred method). As here:

(…) what happened when I saw a picture of my wife. This had me concerned, but Iacoboni explained: “The dorso-lateral prefrontal-cortex activity means you’re trying to exercise cognitive control, that you’re trying to protect the privacy of your relationship with your wife. I interpret this positively because there’s also medial orbito-frontal cortex activity, which is a region associated with positive emotion.” Iacoboni could not explain one other response to my wife’s photograph: “You have weird auditory-cortex activity, almost like you’re hearing her voice, even though we just showed you her picture without sound.”

OK, so give me some (peak) activation in the brain, and I’ll try to interpret it. I’m the Rorschach inkblot master, just bring it on! Actually, thes best thing with this article is the humorous angle that Goldberg puts to it. Just following the above citation, he notes:

When I told my wife about this, she asked me how it could be that I hear her when she’s not speaking, but don’t hear her when she is speaking. I said that this was a question well beyond the capacity of neuroscience to answer.

To newcomers and outsiders, it is crucial to understand that there is a substantial difference between studying brain activation related to specific behaviours and/or tasks, and to go the other way and interpret mental states or behaviour from brain activation patterns. The brain is much more than a collection of highly specialized regions, and there is considerable redundancy and degeneracy in the brain. This means that one structure can be involved in many different functions, and one function or state is often served by many different regions at any one time. So whether your brain responds with the amygdala to a particular face, compared to other faces, may not even mean that you fear or are concerned with this person. The amygdala may be involved in positive emotions, or even novelty processing. Brain-reading is a fascinating topic, but we should steer away from the absolute claims that one can sometimes see today.

One good example, in the present article, of what this approach may lead to is the finding that the author showed ventral striatal activation to the Iranian political leader, Mahmoud Ahmadinejad. So ventral striatrum is related to (expectation of) reward, right. And previously, activation in that region to other famous people was interpreted as a liking-effect, right. Now what? Does Goldberg like Ahmadinejad? Will the NSA knock on Goldberg’s door in the near future? Is it illegal or suspicious for his brain to respond favourably to Ahmadinejad?

This, and more puzzles are definitely going to come up in the near future, as Iacobini and other researchers are concinuing this flaky path of BS science. I’m a great fan of Iacoboni’s academic work, but I am nevertheless terribly dissapointed with his uncritical turn towards entertainment with fMRI.

-Thomas

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brain-reading.jpgBack in February, BBC ran a story about fMRI researchers – shock, horror! – now being able to read people’s minds. In actual fact, the story was a bit more benign. Using a fairly new (and little used) type of fMRI analysis called “multivariate analysis” researchers such as Geraint Rees and John-Dylan Haynes are presently attempting to associate individual mental states with specific patterns of BOLD signal activity. If the mental states of interest can be precisely delineated it is possible to determine if a subject is “in” mental state A or B just from looking at the scanned fMRI data. For instance, in one experiment, described in the BBC story, subjects were asked to either subtract or add numbers shown on a screen without telling the experimenters which of the two potential choices they actually went with. Just by looking at the obtained scans Haynes and his colleagues were able to infer, in 70 % of the cases, whether the subject chose to add or substract – thus, to some degree, being able to “read” the subjects’ hidden intentions. Of course, in reality, the experimenters’ mind reading ability was extremely limited, being focused on only two, highly simple, forced choices. (If you want to read a good presentation of the mind reading possibilities offered by multivariate analysis, see this paper by Rees and Haynes.)

Yet, with all the recent talk about fMRI lie detection and what have you, work such as Haynes and Rees’ on multivariate analysis raises a number of interesting neuroethical questions. On May 9, Haynes is convening a bunch of top-notch speakers to discuss these questions, including Daniel Langleben (of fMRI lie detection fame), Adrian Owen, Henrik Walther, and Thomas Metzinger. He presents the colloquium with the following words:

Every thought is associated with a characteristic pattern of activation in the brain. By training a computer to recognize these patterns, it becomes possible to read a person’s thoughts from patterns of their cerebral activity. In this way a person’s brain activity can betray their thoughts and emotions, can gives clues whether they are lying, or can even predict what they are about to do.

This recent progress in brain science has made completely new insights into thought processes possible. We can now investigate how thoughts are stored in the brain, or how intentions unconsciously arise and affect our behavior. But these findings are not just of interest for the scientific disciplines involved. They have important implications for our understanding of human nature. Also, they lay foundations for important applications: For example, with the help of a “brain computer interfaces”, paralysed patients can control technical devices solely “with the power of their thoughts”.

In the 11th Berlin Colloquium, brain scientists from the USA, Canada and Europe will present this new field of “brain-reading”, while at the same time providing a forum for discussion on the future perspectives of these methods. In particular, the ethical question will be of interest, to which extent such “thought technology” is compatible with “mental privacy”.

It should be well worth your time going.

-Martin

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Is it really so that fMRI can enhance lie detection? This entirely depends upon your method of analysis, the experimental setup, and especially controlling for factors that influence the scanning results. Let’s take them one at a time

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