This week Dr. Roger Newport will be appearing onThe Health Showtalking about our arthritis project.
The Health Show is a new series that covers the latest advances in health related science and technology. This week they have a section on the MIRAGE technology and how we are using it to reduce pain in arthritis.
Roger demonstrating MIRAGE on The Health Show - BBC World
Image provided by Rockhopper.tv.
During the Show Roger will be demonstrating the technology as well as explaining what our research is all about and why we think it works. Our original findings published in Rheumatology (available free online) showed a dramatic reduction of pain in 85% of a sample of osteoarthritis sufferers. Since then we obtained a grant from the Dunhill Medical Trust(ongoing) to continue with the research.
The show will be aired on BBC World this Saturday at 10:10 and 20:10 GMT and again on Sunday at 07:10 and 23:10.
Not just arthritis: The MIRAGE was originally developed to investigate action and body representations of which pain is only one aspect (to learn more about how the MIRAGE was developed see our ongoing blog series - From Box Files to the British Science Festival). The MIRAGE allows us to create various weird and interesting bodily illusions that are not only fun, but can help tell us about how our brain represents and controls our body. You can find out about the different illusions we use from our quarterly illusion blog posts. The next (Winter) illusion - coming soon - will be the Disappearing Hand Trick, which was used for the latest MIRAGE publication (Current Biology) investigating body awareness.
Here is Part 2 of the series on how and why the MIRAGE was developed
If you remember, I was trying to make adaptation to visual shifts (like when wearing prism goggles) more flexible. To do this, I hacked into some motion tracking software (this tracked a sensor on the hand as it moved through space) so that I could read and change the x, y and z coordinates of the cursor on a moment-by-moment basis. This created a system whereby the cursor could either track the location of a subject’s hand, or could be manipulated to move independently of it. Once I could do this, I could show a cursor (a big black dot) to the subject as a representation of their hand location. When I first tried this I glued a projection screen that I found in my loft onto the top of a box, and hung a projector from the ceiling so it shone down onto the screen. The subject’s hand was inside the box with the motion tracking sensor on so wherever the hand moved inside the box, a black dot followed it around on top of the box. This, I suppose, was Mark 1, but I didn’t like it for two reasons: firstly a cursor is not a great representation for the hand and secondly, the projected cursor was not in the right spatial location as it was always above the hand. This was a problem for some people, especially patients with brain damage, as they would always lift their hand up to try to match it to the cursor location above.
Mark 2 was made out of box files, a stolen mirror and some drafting paper (a bit like greaseproof baking paper) and was designed to solve the second of these problems. The projector shone down from the ceiling onto the paper and, because it was a little bit see through, the image of the cursor could be seen on the underside of the paper as well. A big mirror, rescued from a skip, rested precariously on box files so that it lay horizontally exactly half way between the paper and the table. Now, when the subject looked down into the mirror, they could see a reflection of the cursor (above) so that it appeared to be at the same level as their hidden hand on the table (below the mirror). So the cursor was now in the right place, but it still looked like a cursor, not a hand.
This post begins a series written by Dr. Roger Newport about how and why the MIRAGE system was developed.
I am often asked how MIRAGE came about, how I thought of it and how I designed it. The truth is that it all came about by chance - I was actually designing something else. About 10 years ago I was experimenting with prism goggles. Prism goggles shift everything you see over to one side so that when you point at something, you miss it. After a while your brain gets used to the visual shift and you learn to point accurately again, but when you take the goggles off you overcompensate and miss to the other side (because your brain has adapted to the visual shift). While this is very interesting as it helps us to understand how the brain learns and adapts to new tasks, I felt that the fixed visual shift of prism goggles was too simple and that it would be more interesting if we could create a situation where the brain has to learn something more dynamic and flexible. At the same time, I was also messing about with mirrors. You can try this one at home: Fix a mirror upright on a table (I actually had a big mirror wedged vertically between two tables), then put one hand either side and look into the right side of the mirror so that you can see a reflection of your right hand where your left hand should be. Now repeatedly point backwards and forwards (towards and away from your body) either side of the mirror with both hands between two (or more) fixed points while looking at your ‘left’ hand. After about 40 reaches, stop with your hands at the furthest point and peer round the left side of the mirror to see where your left hand really is. You will probably find that it has drifted off either away from the mirror or towards it without you noticing. Sometimes it can drift more than 20 cm and you still won’t notice.
Participant reaching to targets either side of an upright mirror. Instead of seeing the real left hand only a mirror reflection of the right hand (appears like the real left hand) can be seen.
How does this work (assuming it has if you’ve just tried it)? When you look in the right side of the mirror, what you see as your ‘left’ hand is obviously actually just the reflection of your right hand. However, because it happens to be in the right place at the right time, your brain will treat it as if it was your real left hand. Your ‘left’ hand won’t be very accurate at pointing to the targets because what you’re actually seeing is a reflection of the right hand (that you’re not looking at!), so it will appear to miss the target by a small amount each time. Your brain will try to correct for the error of your ‘left’ hand but can’t because it is actually your right hand, and so over the course of many reaches these small corrections all add up and you find that your real left hand has drifted off significantly to the left or right without you noticing. The direction the left hand drifts will depend on which way the right hand missed on the first reach. Here is a series of videos that demonstrate what I mean.
Set-Up as the participant sees it. Note that the 'left' hand appears to be pretty accurate throughout.
This video you shows what the hands are actually doing and you can see the left hand starting to drift off to one side.
In the final video you can see that the participant almost hits the mirror and even changes hand posture without noticing, demonstrating the illusory power of seeing a hand in the right place at the right time doing approximately the right thing.
Next time: How these seemingly unconnected ideas began to fuse into what eventually turned into MIRAGE.
Last week on 13th October was World Arthritis Day, for which Roger Newport was asked to give a talk for the an event put on in Birmingham the day before. Roger used his talk to outline his wish that our research (past and present) acts as a stimulant for new research into pain in musculo-skeletal disorders by the wider research community. He also hoped that publicity from the research would help people understand a bit more about how pain works and that pain-killers are not always the answer.
The event itself was very successful generating a lot of interest about our work and other similar work taking place in the field.
Roger talking about finger stretching during his talk to Arthritis Care last Week. It is a very rare sighting of Roger in a suit.
Roger is guest speaker at an event in Birmingham to promote Arthritis care in the UK and will be talking about our current research project investigating pain reduction in arthritis. The event, to be held on Tuesday 11th October, is a prelude to celebrating World Arthritis Day, which is also this week on Wednesday 12th October. The aim of World Arthritis Day is to increase awareness of arthritis and this year's theme is"Move to Improve"highlighting the importance of movement for those with arthritis and rheumatoid disorders.
One of the biggest problems for those suffering from arthritis, as well as the pain, is restrictive movement: the less the joints move the more they cease up, further restricting movement. Pain itself can restrict movement: because moving is so painful it is avoided. So this is why World Arthritis Day wants to promote movement and research that may help manage some of the pain experienced in arthritis, including our Dunhill Medical Trust Project.
OK..... so these monthly illusions aren't exactly monthly, but we have been very busy with the new grant so they will now be quarterly illusions. Therefore, September's illusion is our autumn illusion, which is pulling the finger off, and stabbing it
This illusion was developed from the finger stretch illusion that we covered in June and was involved in our paper published last year in Perception. It was found that when stretching the finger participants still feel like it belongs to them, whereas when we pull the finger tip off they no longer feel like it is their hand, even though they still have control over the hand and the detached finger tip. This therefore separates the sense of agency (feeling in control of an action) and ownership (feeling like the hand belongs to you). Ownership is measured in this example by attacking the hand and finger with sharp implements whilst measuring skin conductance (tiny changes in the amount we sweat) from the other hand. Increased ownership is associated with higher skin conductance in response to threat - basically you sweat a little bit more when you perceive a sharp stick to be quickly approaching part of your body opposed to approaching something that isn't part of your body.
First the finger is stretched before being pulled off and attacked by the experimenter. The trick is to pull hard on the finger until the moment it detaches when pressure is released so it feels as though the tip has come off.
In the video above the threatening stimuli has been slowed down for demonstration purposes but it shows the experimenter's hand attacking the participant's hand with a sharp stick and a syringe. You can also see the experimenter placing a block between the stump of the finger and the detached fingertip. This served as a convincer showing that the tip was detached opposed to part of the finger being just hidden.
Roger and Helen have just come back from the British Science Festival in Bradford where they demonstrated Finger Stretching, the Disappearing Hand Trick, giving people an extra (supernumerary) hand and making the security officer’s watch disappear. The Disappearing Hand Trick was by far the most popular and details of this multisensory illusion will be published later this year in the journal Current Biology. The Disappearing Hand Trick involves making it seem as though your right hand has disappeared from your body by making you unable to see or touch it. We’ll be describing some of these multisensory illusions in full in future posts, so keep checking back for those.
Helen clearly excited about the day.
Roger and Helen also took part in a Sensory Night at the Society for Dyers and Colourists in Bradford which was an adults only event and great fun. Attending this event involved taking our equipment apart, bundling it into the back of a taxi and putting it back together again in a hurry at the other end. It’s the first time we’ve ever tried this, but it went quite well and only took half an hour to rebuild. Roger had a lot of people ask him how and why he invented MIRAGE so one of our future features will cover the development of ideas and equipment that led to where we are today – from box files to the British Science Festival.
