About Rationally Speaking

Rationally Speaking is a blog maintained by Prof. Massimo Pigliucci, a philosopher at the City University of New York. The blog reflects the Enlightenment figure Marquis de Condorcet's idea of what a public intellectual (yes, we know, that's such a bad word) ought to be: someone who devotes himself to "the tracking down of prejudices in the hiding places where priests, the schools, the government, and all long-established institutions had gathered and protected them." You're welcome. Please notice that the contents of this blog can be reprinted under the standard Creative Commons license.

Tuesday, October 17, 2006

Out of body? Nope, inside the mind!

A recent New York Times article reported on two papers published in Nature and in Brain magazines by a group of researchers at the Ecole Polytechnique in Lusanne (Switzerland), guided by neurologist Olaf Blanke. This is good stuff, that should take care of the whole paranormal mumbo-jumbo about out of body experiences (but of course it won't, just like modern astronomy hasn't gotten ridden of astrological mythology).

Blanke and colleagues have shown that small electrical currents in certain areas of the brain involved with multi-sensorial perception, such as the angular gyrus, cause the distinct sensation of out-of-body experience or of a strange presence in the room. One patient had the feeling of hanging from the ceiling, another was sure that there was a presence behind her, and a third one felt a “shadow” next to her, attempting to interfere with her activities. These experiences are repeatable under laboratory conditions, which means that a hallmark of parapsychology – out of body experiences – can actually be turned on or off at will by the experimenter, has been traced to perturbations of specific circuits in the brain, and of course has absolutely nothing supernatural about it.

The explanation for this class of neurological phenomena is similar to that of the so-called “phantom limbs,” truly bizarre experiences that were once relegated to purely psychological phenomena but are now understood as a byproduct of the normal functioning of the brain. In the case of phantom limbs people who have lost, say, a leg or an arm keep complaining of itches, or even pain, emanating from where the limb used to be. Until a few years ago these patients were thought to suffer from psychological damage at the shock of losing a part of their body and to react with, essentially, wishful thinking that the part were back into place. It turns out that the severed nerve endings keep sending signals to the brain, which attempts to make sense of them while re-wiring the sensorial circuits. It is this disconnect between the wiring of the nervous system and the mental map of one's body that generates the weird sensation of a phantom limb. The feeling, incidentally, often disappears months or years after the injury, once the brain has had time to rewire its sensorial circuits and properly adjust to expectations concerning the spatial extent of the body.

The phenomena studied under controlled conditions by the Swiss group occur in normal people as well, as a result of a variety of factors including extended sensorial deprivation (during open water sailing, or high elevation trekking), strokes or other disruptions of blood flow to the brain, and, possibly, in pathological conditions such as schizophrenia.

Well, now we have a nice scientific explanation of a range of formerly paranormal phenomena. The explanation is consistent with what we know of human neurobiology and psychology, it is testable and repeatable under laboratory conditions, and accounts also for non-paranormal phenomena such as phantom limbs. Case closed, right? Yeah, right...


  1. Nice post! Reminds me of an interesting problem called Alien Hand Syndrome.

    In which a person's hand seems to behave with a mind of its own - must be rather disturbing.

  2. Of course the obvious paranormal reply will be that the out of body experience is real, and the brain manipulations make us "open" to it.

    I read that test pilots in those high acceleration simulators (you know, the seat is at the end of a swinging arm which is spun around)experience the "light at the end of a tunnel" experience that is supposed to go along with near death experiences. The article said that lack of oxygen in the brain was the culprit. Doesn't keep people from believing that there is something to that experience either.

    Willful self-delusion seems to have no limits.

  3. "The phenomena studied under controlled conditions by the Swiss group occur in normal people as well, as a result of a variety of factors including extended sensorial deprivation (during open water sailing, or high elevation trekking), strokes or other disruptions of blood flow to the brain, and, possibly, in pathological conditions such as schizophrenia."

    Also if you mix enough hash and booze. (just feeling nostalgic)

  4. Are those current issues of "Nature" and "Brain?" I would like to read them. I found the NYT article but I can't read it.

  5. Some events one might not exactly attribute to the paranormal, but one does not know exactly why they happened either.

    I know this story sounds slightly off-the-wall, but you'll just have to take my word for it that it happened.

    I remember a time in my late 20s early 30s when I was still more or less searching out was true about God the Bible and science. I believed in God, but there were a lot of things in my mind that I had not reconciled with yet. So of course my kids sort of had to go on the journey with me. At this particular time in my life, I was reading a lot of both secular and faith based material on science and what have you.

    One day my son is reading a supplement to his science, "Of Pandas and People" out loud to me. At the same time I happened to be listening to a radio program at around 12:30 pm where a Dr. Mark Eastman is just beginning to talk on a subject.

    (this is not a link to that particular subject being discussed, it is just commentary by Dr. Eastman on rationally being able to discern the existence of God)

    As he begins to talk and my son is reading a segment on genetics from "Of Panda's and people", all of a sudden my brain tunes into the fact they are both speaking and reading almost identical words and ideas in sequence about genetics one just a second or two before the other. And this went on for several minutes. It was so odd, and only "I" (and God) knew this was happening. My son and Dr. Eastman didn’t know, obviously. It was like it was all just for ME!

    For me? When did God ever care just for me?

    It was like God knew so very well that my brain was full of questions. And for the first time in my life, I was completely aware that He was NOT IN THE DARK about my questions!

    what a revelation!


  6. Massimo,

    Did you happen to remove the intro of Dr. Eastman's commentary?

    The article is relevant to the topic at hand, btw. Thought that some might prefer the word(s) of a person with his phd.

    I do not uninformedly, or haphazardly pick and quote just any old person who happens to promote a creationist world-view. I do sincerely think that Dr. Eastman is a reasonable person.


  7. Cal,

    I rarely delete comments, but yours (which, btw, was simply signed "anonymous") had nothing to do with the topic of the post. If you wish, you can post the link again, appended to a more appropriate post (we've got many on creationism, as you know), and with an explanation of why.

  8. I just happened upon your site and I like it. It is well written and I agree with much of what I have read which helps in the “I like it” part. I’m looking forward to reading more.

  9. For those of you who might be interested:, this page includes some of the best evidence for paranormal experiences like near-death experiences being what they claim to be...

    "NDEs Absolutely, Positively NOT Caused By Malfunctioning Brains"


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