Ego tunnels, conscious entities, virtual bodies and so on.

I have yet to read the book by Thomas Metzinger, The Ego Tunnel, but it's in the cart. Meanwhile I came upon a blog post, two in fact, by Peter Hankins at Conscious Entities blog, that set off a little speculative burst in my own brain.

Part I, and Part II.

In particular, this got my attention;

"There are many interesting details in this account, quite apart from its value as part of the overall argument. Metzinger briefly touches on four varieties of autoscopic (self-seeing) phenomena, all of which can be related to distinct areas of the brain: autoscopic hallucination, where the subject sees an image of themselves; the feeling of a presence, where the subject has the strong sense of someone there without seeing anyone; the particularly disturbing heautoscopy, where the subject sees another self and switches back and forth into and out of it, unsure which is ‘the real me’; and the better-known OBE."

It makes sense to me that multiple self-constructions/constructions of self would exist, given that there are many different body representations all throughout the brain, not just the big S1 map stretched over the top of the cortex, the famous one Wilder Penfield mapped out, and I didn't realize there were names already ascribed to the elicitation of their specific distortions..

A body misperception can be the absence of a familiar body sense just as well as it can be one that's displaced onto a mannequin or onto someone or something else entirely, or floating above.. in each case there will be a corresponding shift in neural traffic flow, the brain not operating in its own familiar manner, and part of it noticing that shift and confabulating predictive perceptual fantasies as to possible reasons why. As in the Charlie Rose Brain Series Part II, in which all the various visual perceptual distortions were touched on, body sense is subject to perceptual distortion. The science on this is younger, but is definitely happening, mostly in Europe, mostly referred to as research of virtual bodies, rubber hand illusions, etc etc. discussedmany times on this blog. It's all very fascinating, and likely to have a lot to do with learning to handle human pain issues much more adeptly with fewer drugs at some point.

Meanwhile, it won't be a bad idea to practice feeling your own normal body better, practice using normal brain pathways, strengthen them so that your brain maps don't get all out of whack some day, and in some misguided attempt at trying to locate body parts, make them spasm or make them hurt to be able to find them more easily - the neurological equivalent of lighting flares to see along a dark path.

Other reading:
1. Book review at Naturalism.org

Moving into a robotic hand

Here is another wonderful Mindhacks post: Inhabiting a robot hand Thank you Mindhacks.

This relates to all the posts here to do with robotics, haptics, virtual bodies, virtual body manipulation through mirror therapy or video, and rubber hand illusions. NOI twittered about the Mindhacks post in conjunction with Graded Motor Imagery, the virtual treatment they are promoting. Definitely worth boosting here as well.

More about virtual bodies

In reference to More about glia, and a Neurophilosophy post on Moseley:

Today's post is short, because Mo has already written it. :-D He's called it The body-swap illusion.

In it Mo explains new work by Henrik Ehrsson, now in Stockholm, the paper If I Were You: Perceptual Illusion of Body Swapping, by Valeria Petkova and Henrik Ehrsson.

Thanks Mo, thumbs up for a great post.

I don't know what more evidence could be found to support the idea that the perceptual brain is in charge of autonomic outflow than to persuade it by means of illusion, both visual and tactile, that it was responsible for maintaining the bodily integrity of a mannequin, then physically threaten the mannequin and measure autonomic alarm as represented by evoked skin conductance response (SCR).

UPDATE Dec 16: Rubber hands feel real for amputees. Thank you again, Mo from Neurophilosophy.

Monkey intentions and control of a robotic arm

In a brief departure from a current catch-up I'm doing on glia, I want to catch up some old posts, thoughts, themes and developments to do with the brain as movement simulator.

In reference to blogposts The devil is in the Details (Dec 18/07), More on Learning (Dec 21/07), and The User Illusion, Dec. 22/07:

Today Deric Bownds Mindblog post featured a short piece about a big big topic:
Science Hack - monkey brain moving robotic arm. Readers can follow the links and find the great little video - as usual, a food reward proved to be the most effective for getting a monkey to neuroplasticize its brain... this monkey can't move its own arm but it learned to move the robotic one to reach food and put it into its own mouth. Remarkable. It appears that with the right motivation a brain can learn whatever it needs to.

Additional Reading:
Differences Between Intention-Based and Stimulus-Based Actions (12 page pdf)
.

Something in Swiss water?

I am starting to wonder what it is about Switzerland. In the past few months, three separate science projects jumped out at me, all Swiss and all brainy:


1. VIRTUAL BODY EXPERIMENTS:

These are described in the blog post Virtual Body Experience. The third was by Bigna Lenggenhager:

"Swiss scientist Bigna Lenggenhager induced virtual body illusions in her subjects, then had them move themselves out of position, then back into positions where they thought they had previously been, but which were in fact where their "virtual" bodies had been.

Her paper “Video Ergo Sum: Manipulating Bodily Self-Consciousness” was also published in the August 24, 2007, issue of Science."

Here is a related video.


2. BLUE BRAIN PROJECT:

This is a Swiss project headed by Henry Markram, in which an artificial "brain" is being painstakingly built. Jonah Lehrer writes,

"In the basement of a university in Lausanne, Switzerland sit four black boxes, each about the size of a refrigerator, and filled with 2,000 IBM microchips stacked in repeating rows. Together they form the processing core of a machine that can handle 22.8 trillion operations per second. It contains no moving parts and is eerily silent. When the computer is turned on, the only thing you can hear is the continuous sigh of the massive air conditioner. This is Blue Brain."

So far the project has managed to accurately simulate a single cortical column from a two-week old rat brain, only... but is still an amazing achievement. Here are media links.


3. PHYSIOTHERAPY THINKING:

A systematic review in press for Manual Therapy:

Paradigm shift in manual therapy? Evidence for a central nervous system component in the response to passive cervical joint mobilisation

Annina Schmid, Florian Brunner, Anthony Wright and Lucas M. Bachmannd
a Uniklinik Balgrist, Department of Physiotherapy, Forchstrasse 340, 8008 Zurich, Switzerland
b Uniklinik Balgrist, Department of Rheumatology, Forchstrasse 340, 8008 Zurich, Switzerland
c School of Physiotherapy, Curtin University of Technology, Perth, Australia
d Horten Center for patient-oriented research, University of Zurich, Switzerland
Received 28 February 2007; revised 30 November 2007; accepted 18 December 2007. Available online3 March 2008.


Abstract

Segmental neurological modulation, neural hysteresis and biomechanical effects have been proposed as mechanisms underpinning the effects of manual therapy. An increasing number of studies hypothesise activation of the central nervous system resulting in a non-segmental hypoalgesic effect with concurrent activation of other neural pathways as a potential mechanism of action. Whether this model is consistent with the current literature is unknown.

This systematic review aims to assess the consistency of evidence supporting an involvement of supraspinal systems in mediating the effects of passive cervical joint mobilisation.

We searched randomised trials in three electronic databases from inception to November 2007, without language restriction, and checked reference lists of included studies. We assessed study validity and extracted salient features in duplicate.

Fifteen studies met our inclusion criteria. The overall quality was high. We found consistency for concurrent hypoalgesia, sympathetic nervous system excitation and changes in motor function. Pooling of data suggested that joint mobilisation improved outcomes by approximately 20% relative to controls. This specific pattern suggests that descending pathways might play a key role in manual therapy induced hypoalgesia.

Our review supports the existence of an alternative neurophysiological model, in which passive joint mobilisation stimulates areas within the central nervous system.


Keywords: Treatment outcome; Cervical pain; Neck; Manipulation spinal; Joint mobilisation techniques; Physical therapy (speciality)"

Whatever the Swiss have going on there, I hope it doesn't lose any momentum, especially in view of the fact that it would appear brain consideration is making it all the way into Swiss PT culture, and out into the world of manual therapy. (Big smile)

Getting past fear

In reference to FABQ and physical therapy:

Cory, I have to confess up front that I've never used this questionnaire with any of my patients.

I completely concur with your conclusion:

Bottom line, change the belief about pain and you change the way a person behaves in response to pain. Change the behavior in response to pain and you can change the pain itself.

This post by Matthias also references Waddell's book and the biopsychosocial model, here.

The brain seems to be attracted to novelty, even if only the novelty of a new idea (it must find the "new idea" nonthreatening of course..). This ties in with Melzack's pain model, where the neuromatrix constantly folds in cognitive evaluative, sensory-discriminative, and motivational-affective inputs, to produce its outputs, one of which might be pain perception.

The other thing the brain finds convincing, possibly even more so, is illusion, whether visual (as with mirror therapy a la Ramachandran, or with videos a la Ehrsson and Lenggenhager and Blanke) or kinesthetic ("movement illusion" as per Collins et al) or perhaps both. (Here's a little study idea I had late last year..)

If the illusion is convincing enough to the brain, it doesn't seem to matter if the "mind" is convinced or not - people seem overwhelmingly capable of suspending any disbelief they may have. The mirror therapy is sufficient proof of that - the amputee patient is fully aware they are looking at their remaining limb move in a mirror image, yet the illusion still works. A large-scale trial of mirror therapy is currently underway at Walter Reed army hospital.

It looks to me like our PT work will just keep on evolving and get easier and easier, the more the brain/ nervous system comes to be understood and appreciated, the more we learn to understand how it perceives and constructs a reality for itself and the human body it is meshed with.

Visual Feedback for Backs

Response to Visual Feedback.

Matthias, I can see how treating could be done right now, with the right equipment.. much like your idea about treating paraplegic central pain.
I was thinking of something perhaps a bit more ambitious and potentially devious, however; how one might design a study to determine if back pain could be treated virtually, using these "virtual back" studies as a point of departure.

Think of the possibilities: if it could be shown that back pain/neck pain could be treated visually/virtually instead of being the huge treatment morass it is right now, several ramifications might ensue.

1. Heavy, structurally based manual therapy could potentially be made obsolete in the future. (:D)

2. Potential big cost savings for everyone; patients wouldn't have to suffer as much for as long. Employers would save insurance costs. Insurers would save on disability claims. Aspiring professional human primate social groomers wouldn't feel obliged to pay out huge $ for manual therapy courses of under-studied or dubious quality taught by greedy "gurus".

3. Humans might actually suffer, overall, less low back pain as an industrialized, domesticated species, in the future.

Just some wild and crazy thoughts. Dare to dream I say..

Virtual Body Experience

Check out the article, How to Excuse Yourself From Your Body, from the magazine Discover.

Swedish scientist H. Henrik Ehrsson devised a way to convince people's brains that what they were looking at, an image of their bodies projected in front of them, were in fact occupied BY them. He proved that the brains responded to the illusion "as if" it were real; he provoked measurable autonomic distress output by threatening to hit the "virtual" body with a hammer.

His study “The Experimental Induction of Out-of-Body Experiences” was published in Science, Aug. 24, 2007.
(See here for list of 30 of his articles.)


Swiss scientist Bigna Lenggenhager induced virtual body illusions in her subjects, then had them move themselves out of position, then back into positions where they thought they had previously been, but which were in fact where their "virtual" bodies had been.

Her paper “Video Ergo Sum: Manipulating Bodily Self-Consciousness” was also published in the August 24, 2007, issue of Science.

How is this possible?

The Discover article says,

"While we navigate the world, our brains are constantly integrating sensory information gathered by sight, touch, and hearing. But sometimes the system goes haywire, and people experience the illusion that they are outside their physical bodies, floating above them and peering back from a distance of about 6 to 10 feet. These “out of body” experiences typically occur when people suffer strokes, epileptic fits, or migraines or are taking drugs. Two cognitive neuroscientists explored the boundaries of body perception by reproducing an out-of-body experience in the lab."

Experiment I:
Henrik Ehrsson, Karolinska Institute in Stockholm, Sweden

- 18 healthy individuals were seated. Their backs were filmed with a pair of video cameras while they wore goggles that
a)gave them a stereoscopic view of their backs
b)captured the video from both cameras.
- Ehrsson induced the illusion; he "repeatedly touched each person’s actual chest with one rod while, with another rod, he jabbed toward a point below and in front of the two cameras that corresponded to the “virtual chest” of the image projected into the goggles. With the shift in perspective through the goggles, subjects reported that they felt as though they were physically embodying a space six and a half feet behind where they actually were."

Experiment 2:
Ehrsson wanted to find out if the subjects would respond "as if" they were located in the illusory position.
- Sensors that monitor electrical conductance were applied to the subjects.
- The first experiment was duplicated.
- This time, "he swung a hammer toward the two cameras at a point corresponding to the center of the face of the camera-generated illusory body"...and, "the subjects’ skin showed a spike in electrical conductance—a sign of increased sweating and emotional arousal—and they reported immediate anxiety."

Experiment 3:
Bigna Lenggenhager et al., École Polytechnique Fédérale in Lausanne, Switzerland

- A camera was placed six and a half feet behind the back of each of 14 participants wearing 3-D video goggles.
- Their backs were stroked with a large pen; they could simultaneously see and feel their backs being caressed.
- The subjects were guided backward, then asked them to return to their previous position.
- "Participants overshot the distance by an average of 10 inches, moving closer to the position of their “virtual” bodies."

- The back of a mannequin's body was stroked, and the image projected into the subjects’ goggles. Subjects felt that the mannequin’s body was their body.

“We now understand how the brain combines information from the eyes and from the skin to compute or determine where the self is located in space,” Ehrsson says. Both experiments show how easily the brain can be tricked or how it “cheats,” he says, using memory and prior experiences to fill in data gaps."

Here is a youtube video about this. (Olaf Blanke, shown in the video, was Lenggenhager's team leader.)

Here is a link to Sandra Blakeslee's new book, The Body Has a Mind of its Own, which discusses these kinds of phenomena and attendant research in greater detail.

Just one additional thought for now.. why wouldn't this setup work for treating back pain? Someone could find 20 or so subjects with back pain, any old kind of back pain at all, acute, chronic, what have you, any age, any sort of work, any socioeconomic group... put the goggles on them, induce the illusion. Instead of getting the subjects to move forward and back or instead of eliciting threat responses from their autonomics, instead, the "virtual" backs, could be "treated". Or a film clip of the "virtual" back could be shown to move freely. I wonder if this illusion would be sufficient to get the subjects' brains to stop producing the pain output?

Dec. 29th '07: Back in to add a link to a youtube video on goggle-induced virtual reality games for phantom limb pain.