Parlor Tricks to Lose Yourself In
You don’t need ketamine to produce such dissociations, however; if you have the money, you can do it with immersive virtual-reality technology. For the rest of us there are some simple optical tricks.

For example, try looking at a Halloween mask through a shiny pane of glass, so that you see a reflection of your face superimposed on the mask. By changing the relative illumination of the mask and your face, you can optically blend the two to produce a strange hybrid creature. Now make odd facial expressions, and you will get the impression that the creature is mimicking your contortions in perfect synchrony. The experience should give you a momentary sense of decapitation—an inkling of what it must feel like to take ketamine.

The illusion will be enhanced if you place two panes of glass at right angles. Shift your head until the reflection of the center of your nose is exactly on the corner of the two panes (and superimposed on the mask behind). If you now wink your right eye, the reflection will wink its right eye (the double reflection violates an ordinary reflection’s left-right reversal). The result is an even more compelling illusion that you occupy the mask.

If you go to the next level—which involves a combination of lighting, makeup, mannequins and a hall-of-mirrors effect created when you stand between two body-length mirrors that face one another, producing an endless number of optical clones of yourself—you start to approximate the effects of ketamine. In the mid-1990s we showed (with William Hirstein and Eric L. Altschuler of the University of California, San Diego) that punching the mask under these conditions produces instant fright. We measured subjects’ fear objectively by monitoring changes in their skin resistance—that is, how much they sweated. If I threatened any old mask you were looking at (without using optics to help you identify with it), you would not flinch. It’s the sense of merging with the “other head” that does it.

More recently, scientists have used video cameras to produce similar “disembodiment” illusions, in which people feel they are projecting their body to some outside location. These spooky experiences are of the kind that might occur after, say, a stroke damaged the right parietal lobe. This is the area of the brain that seems to be partly responsible for creating body image, a sense of inhabiting one’s own form.

Patients with right parietal lobe damage sometimes feel they are seeing themselves from the outside (as with ketamine), or they may experience a doppelgänger. A few years ago we saw a patient with a right frontoparietal brain tumor who was mentally normal in every respect except that he felt a phantom twin attached to the left side of his body that mimicked his every action. If he was touched, he also felt the twin being touched a few seconds later. Stimulating the vestibular canals in the patient’s inner ear made him feel like he was twirling around and caused the phantom to shrink and shift. (The vestibular system, which contributes to balance and spatial orientation, connects to the right parietal lobe.)

The great English neurologist MacDonald Critchley described many other patients who—depending on the parts of the parietal lobe involved—felt like giants or pygmies; experienced their body parts as distorted or swollen; disowned an arm, claiming it belonged to their mother; or even hated a particular limb—claiming, for example, that “my hand is a communist.” We suggest that the sense of “ownership” of even external objects (wedding rings, tennis rackets) that is so ubiquitous in our species (Gandhi being a notable exception) may have exapted—in other words, developed as a secondary use—from neural systems that originally evolved for body ownership.

16 Comments

1. 1. tharriss 10:00 AM 4/13/10

   Interesting article, but in the future I'd suggest leaving out the attempts at comedy... at least when you choose politically charged targets.
   
   I love a good Palin joke as much as the next (non ultra-conservative) person, but all that does in this article is risk getting some readers upset and distracts from the science in the article.
   
   Thanks!

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2. 2. syncratio400 in reply to tharriss 12:43 PM 4/13/10

   Tharriss, most comedy comes at someone else's expense. The writers aren't trying to make friends, they are writing a scientific article in an entertaining fashion.
   
   You can have your opinion on how to write, but I'm fairly certain you aren't a professional writer. Leave your advice to your field of expertise.

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3. 3. jdlunsford 01:20 PM 4/13/10

   The paragraph describing RSD is horribly inaccurate. RSD can affect any part of the body (not just the arm), and the mirror treatment is a joke - ask anyone who actually has RSD. It's not something that can be treated with optical illusions.

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4. 4. jdlunsford 01:24 PM 4/13/10

   The paragraph describing RSD is horribly inaccurate. It can affect any part of the body (not just an arm). Also, the mirror treatment is a joke and it's efficacy in clinical trials is grossly overstated in this article. RSD is not a disease that can be treated with optical illusions.

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5. 5. NatureTM 01:33 PM 4/13/10

   When I read that about Palin, I sortof thought to myself, "Would she/her followers be insulted?" I concluded most wouldn't, and some may take it as a compliment. Any supporter of Palin and Tea Party politics must certainly be aware they are aligned with the gun rights and ownership subculture. Sarah Palin's shotgun is a symbol of freedom to these groups! I'm surprised I haven't seen any "Sarah Palin's perception of Shotgun ownership is fundamentally no different than Sarah Palin's perception of owning her own arm!" bumper stickers.

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6. 6. Spin-oza 04:54 PM 4/13/10

   Wow... such lame comments regarding the vacuous Palin versus the fascinating research that further establishes what many have known for centuries... and what the late Sir Francis Crick famously postulated: that we ourselves... and our notion of supernatural "souls" and contra-casual free will are in fact illusions, wholly instantiated by our (marvelously evolved) physical brains.
   
   Even a cursory review of either neruoscience or genetics would force any rational person, still able to think critically to arrive at that conclusion. From schizophrenia... to phantom limb syndrome... from autism spectrum disorder to obscession-compulsion disorders and addictions, the evidence is overwhelming.
   
   Any one still seriously entertaining the notion of a supernatural "free-willing" secret-soul-agent, somehow supervening on our physical brains, apart from natural causation... is well... rather "willfully" ignorant.

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7. 7. Marc Lévesque in reply to syncratio400 06:36 PM 4/13/10

   to syncratio400,
   
   Are you by any chance an expert on Internet etiquette
   
   :)

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8. 8. gwernymynydd 03:37 AM 4/14/10

   Thought provoking article. I know nothing about the subject and certainly not specifics such as RSD, but it raises the question as to what 'self treatment' could be feasible, how these findings could link with physiotherapy and whether a Wii program could be created to give pain relief or treatment.

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9. 9. jack.123 06:04 AM 4/14/10

   It's funny that the lame jokes are always the expense of the right,but never the left?

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10. 10. JamesDavis in reply to jack.123 07:53 AM 4/14/10

    "Jack", that is because the "right" is seldom, if ever "right" and the "conservative" is very seldom, if ever "conservative" and you always give a great deal of jargon to poke jokes and negative comments at...so get over it and if you don't like the jokes then change your behavior or learn to laugh at the jokes. After all, laughter is the best medicine and Palin consumes a lot of RSDs.

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11. 11. Wayne Williamson 06:50 PM 4/14/10

    Nice article...looks like they are on to something...(deleted my remaining comments;-)

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12. 12. capthecat 08:33 PM 4/14/10

    Can anybody give me a scientific explanation of what happens in the brains of people who have spontaneous out-of body experiences? Is there something that works differently in their brains? Some people think these experiences can be induced through relaxation techniques and I would be curious to know if any of you was able to experience OOB through relaxation.

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13. 13. jack.123 06:50 AM 4/15/10

    A short study of Buddhism,first working with relaxation techniques,then working with your with colors then objects,and you can work your way up to OOB's.Although it may only be a different state consciousness,but it like humor and beauty are in the mind of the beholder,but with practice,you will be amazed at the visions you can come up with.but it can take a few years to get there.As for scientific proof,I know of no brain scans while meditating going on right now,but it might be something someone should try to get grant for,but It would make for a great doctoral thesis.A faster way obtaining an OOB would be lucid dreaming,the technique is simple.Start keeping a daily journal of your dreams, the more you record the more you will remember,This is followed by giving yourself commands, before sleeping,and then focus on something in your dreams that would make you aware you are dreaming such flying,flying is a good one,because it's something that doesn't happen outside of a dream.I am of course speaking of doing so without an aircraft.When you first become aware in a dream,it can be quite an experience,at first it it short, but with practice you can stay in the dream longer and longer going to where you want and doing what you want uncluding OOB's.Good Luck.

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14. 14. anitalite 03:35 AM 4/17/10

    See how one can invoke a political discussion by dropping a political name in the midst of an article like this? That silly joke (that made me giggle a second) was cute until you nuts took it so far and diverted your thoughts and wasted energy into a messy and silly assault on one another.
    It was just a joke, maybe not appropriate for this, but funny none the less.
    Now, would anyone care to discuss their out of body experience? I thought that is what this article was about.

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15. 15. Tim Owers 05:33 PM 4/23/10

    I don't care about the odd joke here and there, the important thing is this article makes for an interesting read. My only criticism is the detail of the effects of Ketamine could have been �more fully explored. On page 1 you state:
    'Under its influence you empathize with your body the same way you empathize with other people, and you are able to simultaneously detach yourself from it'
    Under a low dose this may well be the case, under higher dosages the effect is far more dramatic. I now know this from personal experience.
    
    Seven days ago I was admitted to I.C.U. (post-operatively). In order to have an epidural inserted into my spine between the shoulder blades I was administered Ketamine. This is without doubt the scariest, most terrifying drug I have ever encountered. Whilst being physically conscious I was convinced I was underwater, in almost total (b&w) darkness, that I was dead, only able to talk in slow motion in a voice that was not my own and in total confusion at no longer having a body. Above all I was totally consumed by utter terror. The (chief) anaesthetist told me later he had never seen such an extreme reaction in all his thirty odd years, and had to very quickly make the decision to put me 'under' to override the Ketamine. In the short time it took to get the artificial respirator and all the other kit up and running I had an endotracheal tube inserted, which I then pulled out again. However, it wasn't me I was pulling it out of! There is of course a lot more than that I write here but I won't bore you with the whole experience, suffice to say, normal nightmares pale into insignificance to this.
    �
    Two days later I 'woke up,' which actually took about three hours to do, and the team were shocked that I could remember every single detail. Normally you remember nothing, or at most fragments. I wish that were the case for me as this is going to haunt me for the rest of my life.

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16. 16. bluewaitui 06:35 PM 10/3/10

    Interesting article. I am wondering about if research is being done or considered regarding if the mirror neurons are dammaged or undeveloped in individuals with Autism, psychopathic or narcissistic disorders. They all have a disability in their ability to put themselves in another's shoes.

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