‘Cool hand’ Moseley



MY OLD MATE and co-author of ‘Explain Pain’, Lorimer (Lozza) Moseley comes up with some off the wall research, but one of the best was the recent “Psychologically induced cooling of a specific body part caused by the illusory ownership of an artificial counterpart” (PNAS 2008 105:13169-13173). I have attached the abstract at the end.

The rubber hand illusion
Lozza et al showed that skin temperature of the hand  decreases significantly if the person’s ownership of the hand can be altered by tricking them into taking ownership of a rubber hand. This can be done by using a well known rubber hand illusion trick – essentially hiding the subject’s  hand  behind a screen as in the image and  putting a rubber hand close by. If you synchronously brush the rubber hand and the real hand, people often perceive the feeling of brushing as coming from the rubber hand.  Try it yourself. It’s a weird feeling, but we believe every therapist should try it. Take care with your rubber hands though. Lorimer has been pulled up in customs with a rubber hand in his luggage and I have been accused of murder by hotel cleaning staff in Sydney. (Always hide your rubber hand to be safe!!)

The findings
The experiment is neat – six experiments with six different groups of volunteers (budding researchers take note). The change in temperature is limb specific i.e it doesn’t occur in the other hand or the foot. This is an important finding, meaning that it is unlikely to be related to a broad stress response and thus seems to be a specific cortically mediated adaptive response. Another finding was that the importance (weighting) of tactile information from the real body part is reduced when the person takes ownership of the rubber hand. Moseley et al summarise the findings succinctly… “ taking ownership of an artificial body part has consequences for the real body part; that the awareness of our physical self and the physiological regulation of self are closely linked in a top down manner; and that cognitive processes that disrupt the sense of body ownership may in turn disrupt temperature regulation in states characterised by both.”

So what does this mean?
I suspect many readers will think “well that’s interesting” and that will be it. But the study should provoke much discussion. (If you google it you will see that the world press was particularly interested)

  • As the authors note – many states such as anorexia nervosa, stroke, epilepsy, autism are characterised by altered body awareness and many of these also have altered temperature regulation as a feature. The findings help with explanations of symptoms to patients.
  • Perhaps we should all reflect on what body ownership is about and how we should include this in the clinic. Patients’ comments such as “it doesn’t feel right” or “it is not mine” or even the common “it feels swollen” may mean a distortion of body ownership. Here is a new research area, one that Moseley and colleagues have already exploited elsewhere, for example in the low back (Moseley GL 2008 Distorted body image and tactile dysfunction in patients with chronic low back pain. Pain doi:10.1016/j.pain.2008.08.001).
  • Somewhat on a tangent…if a person can take on an artificial rubber hand as their own, then what about collars, splints, taping and prostheses?  I have known a few patients where touching the collar hurts. Other clinical/research questions may be around how can we get a person to best accept a prosthesis and how can we wrest away a splint that a person has integrated into the representation of their body.
  • Practitioners utilising visualisation and  mindfulness should be interested in these results
  • These findings also support the worthiness of utilising a neuromatrix paradigm in every day clinical life. More knowledge about how quickly the brain can be changed and how cognitions can rapidly alter physiological processes in the body again challenges the still dominant biomedical approaches to chronic disease states. This research supports biopsychosocial approaches.

And remember – what you think you look like is very adaptable!



Your turn
This week’s prize of the new Explain Pain AUDIO, narrated by David Butler and Lorimer Moseley in their best Australian English goes to the best reply on either the potential clinical applications of the research or clinical story about altered body awareness.

Abstract

Moseley GL, Olthof N, Venema A, Don S, Wijers M, Gallace A, Spence C. Psychologically induced cooling of a specific body part caused by the illusory ownership of an artificial counterpart.

Proc Natl Acad Sci U S A. 2008 Sep 2;105(35):13169-73. Epub 2008 Aug 25.

The sense of body ownership represents a fundamental aspect of our self-awareness, but is disrupted in many neurological, psychiatric, and psychological conditions that are also characterized by disruption of skin temperature regulation, sometimes in a single limb. We hypothesized that skin temperature in a specific limb could be disrupted by psychologically disrupting the sense of ownership of that limb. In six separate experiments, and by using an established protocol to induce the rubber hand illusion, we demonstrate that skin temperature of the real hand decreases when we take ownership of an artificial counterpart. The decrease in skin temperature is limb-specific: it does not occur in the unstimulated hand, nor in the ipsilateral foot. The effect is not evoked by tactile or visual input per se, nor by simultaneous tactile and visual input per se, nor by a shift in attention toward the experimental side or limb. In fact, taking ownership of an artificial hand slows tactile processing of information from the real hand, which is also observed in patients who demonstrate body disownership after stroke. These findings of psychologically induced limb-specific disruption of temperature regulation provide the first evidence that: taking ownership of an artificial body part has consequences for the real body part; that the awareness of our physical self and the physiological regulation of self are closely linked in a top-down manner; and that cognitive processes that disrupt the sense of body ownership may in turn disrupt temperature regulation in numerous states characterized by both.

Last month’s slippery sural nerve
Thanks for all of the interesting sural and other nerve stories – here’s the collection. We decided that Martin Spitzeck had the most suitable story as it best reflects a mondern-day version of Kamerad-Schnuershuh syndrome which was mentioned in the last edition.

“I had a client who was a keen fly fisherman. He spent 2 weeks on the South Island of NZ and ended up with tingling on the outside of his foot. The problem was the waders being tied up to tight. I did some research and found a case of an ice hockey player with bilateral sural nerve entrapment. His problem was putting tape around the laces of the boot compressing the nerve. This was good to show the client of almost an identical cause for him to getting a better understanding of his unusual symptoms.
Treatment involved sural nerve sliding techniques, massage around the calf, amongst avoiding tight fitting boots and waders.”

Thanks Martin! (We all love a good fishing story!!) – and we hope the Neurodynamics DVD and handbook comes in handy..

 

Did you know?
According to a Time magazine poll conducted over 3 years ago, in the United States, over 220 million adults average an hour and a half a day in their cars.

And figures published by the Work Wise UK initiative in 2007 revealed that the average commuter travels for 58 minutes a day and one in ten people have a daily journey of over two hours with 18 million of those travelling by car.

Granted, these are amongst the most congested countries around the world but that’s heck of a lot of time.

David and Lorimer recently got together and recorded their narration of Explain Pain onto a 3 CD set in beautiful Australian english; so it’s now available on backorder and will be available, hot off the press in mid October.

EP audio complements the text by offering a different learning medium. It also provides a way of getting the messages of Explain Pain out to those where reading is not an option.

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