New paper points out flaw in Rubber Hand Illusion raising tough questions for psychology

University of Sussex

 A demonstration of the Rubber Hand Illusion.  Credit: University of Sussex

A demonstration of the Rubber Hand Illusion. Credit: University of Sussex

A world-famous psychological experiment used to help explain the brain’s understanding of the body, as well as scores of clinical disorders, has been dismissed as not fit-for-purpose in a new academic paper from the University of Sussex.

The Rubber Hand Illusion, where synchronous brush strokes on a participant’s concealed hand and a visible fake hand can give the impression of illusory sensations of touch and of ownership of the fake hand, has been cited in more than 5,000 articles since it was first documented more than 20 years ago.

In a new research paper Dr Peter Lush, Research Fellow at the Sackler Centre for Consciousness Science at the University of Sussex, demonstrates that the control conditions typically used in the Rubber Hand Illusion do not do they job they need to do.

His results show that the commonly reported effects of the Rubber Hand Illusion can be attributed to imaginative suggestion’ – otherwise known as ‘hypnosis’.

Dr Lush is calling for the development of valid control methods for the Rubber Hand Illusion while raising the prospect that suggestion effects could confound many other effects throughout psychological science.

He said: “The Rubber Hand Illusion is a cornerstone of contemporary consciousness science. It has been extended to almost any body part imaginable and investigated in just about any clinical disorder you can imagine.

“This paper prompts the reinterpretation of all this work, and other work which uses the same control methods, such as the full body illusion, the out of body illusion and the enfacement illusion. Existing claims that the rubber hand illusion is not a suggestion effect are invalid, and therefore it is possible that existing reports of the rubber hand illusion are entirely attributable to suggestion effects.”

Last year Dr Lush and colleagues reported in a paper, currently under peer review but available as a preprint on PsyArxiv, substantial correlations between response to the Rubber Hand Illusion and response to imaginative suggestion , or phenomenological control, in a large sample of 353 participants. This study shows that response to the Rubber Hand Illusion is, partially or entirely a suggestion effect.

Psychologists have long been aware of the dangers of ‘demand characteristics’ – in which subjects, often without realising it, say what they implicitly think they ought to say.

Dr Lush’s work takes these concerns much further by showing that how suggestible someone is can dramatically influence what people report in the Rubber Hand Illusion – and potentially in many other experiments too.

Dr Lush said: “The extent to which phenomenological control confounds psychological science is currently unknown, but may be substantial. If the effects are widespread – and they may well be – psychology will be faced with a new crisis of generalisability.”

In the new study, published this week in Collabra: Psychology, an innovative design was employed to test imaginative suggestion in rubber hand illusion reports.

Participants were provided with information about the Rubber Hand Illusion procedure (including a text description and a minute-long video demonstration of the illusion) and then asked to fill out a standard questionnaire on what they would expect to happen if they were a participant in the procedure.

Strikingly, people expect the same pattern of results that is typically found in Rubber Hand Illusion studies, both for the ‘experimental’ conditions and the ‘control’ conditions.

According to Dr Lush, this means the control methods that have been used for 22 years of Rubber Hand Iillusion studies, are not fit for purpose because demand characteristics have not been adequately controlled, meaning the illusion may be, partially or entirely, a suggestion effect.

He added: “Few contemporary scientists seem to be aware of the extent to which imaginative suggestion can drive experience, and so haven’t been able to control for suggestion effects in the Rubber Hand Illusion.

“Future studies of the Rubber Hand Illusion – and many other similar effects – will need to take individual differences in suggestibility properly into account, if they are to make justifiable claims about how people experience their bodies.”

###

From EurekAlert!

68 thoughts on “New paper points out flaw in Rubber Hand Illusion raising tough questions for psychology

    • This study used a “large” sample of 353 subjects. Answered a questionnaire after being shown some video and reading a paper.
      Big Surprise- they agreed with what they saw and read.

      353 is way too small a sample. Working with samples of new food products the final test was always over 500 subjects, with no explanation other than seeing the advertising and tasting the product and answering maybe 30 questions. The questionnaire always had several “duplicate” questions that tried to subtly get the same information via differently written questions as a check.

    • The rubber hand illusion: A subject is positioned where he/she can see his right hand and a fake hand resembling his left hand. The researcher strokes both of the visible hands at the same time with a paint brush. The subject gets a feeling that his actual left hand has been stroked and that the fake hand is really his.

      • The unseen hand of fear flips researchers the finger?
        And all the while the ‘researcher’ has your real left hand hidden in their more private area.
        All done for ‘science’ you understand.
        🙂

      • HA, ….. tell the test subject to “close their eyes” …. before any “brush stroking” is applied, ….. then ask the questions.

        I don’t think that psychiatrists and psychologists have ever accepted the reality that people will, more often than not, …… lie to them.

      • “A subject is positioned where he/she can see his right hand and a fake hand resembling his left hand”

        I don’t see that in the photo.

    • Yeah, so what is the “Rubber Hand Illusion”?

      When I first saw the title, I thought ‘Why would anyone research the illusion that a pencil looks like rubber when it’s shaken back & forth in your hand?’ 😉 😉

  1. Other than demonstrating how corrupt (ie: non reproducible) this so-called science is, why do we wast so much time discussing it?

    We’ve pretty thoroughly beat the crap out of this dead horse.

    • Javert, “Peer Review” and the fallibility of it, for one. Also suggestibility of the unaware. Along the line of subliminal suggestion and the subconscious mind. Go back to the 60″s and read Vance Packard’s “The Hidden Persuaders” Now repetition over 5000 articles becomes reinforcement to subliminal understanding.

      So much of the non-science of CAGW is driven off suggestibility and the susceptible nature of the Human Subconscious. This is the principle tool of the Media driven fear mongering in many leftist driven agendas, supported by Hollywood movies and television.

      Note how often they casually slip a “settled sciend fact” without fact, substantiation or challenge, into the dialogue of TV shows and movies. For most people it simple settles in the subconscious mind and they can feel the air is warmer than is use to be when they move around outside.

        • The article you reference doesn’t really reflect your comments. It is more nuanced but even so just skims over an area that is possibly the most complex of any.

        • Thomas – April 10, 2020 at 7:49 pm

          I very much doubt the existence of a subconscious mind in the psychological sense.

          Well now, Thomas, ….. “believe it or not”, …… but your conscious mind is subservient to your subconscious mind.

          “Sleepwalking” is proof-positive that one’s subconscious mind is in control of everything one does.

          Your conscious mind can be put to “sleep”, but your subconscious mind never “sleeps”, unless you are ‘brain dead’.

          Newborns do not have a “functional” conscious mind simply because they are not born with any knowledge of their environment. Their conscious mind develops (is nurtured) as their sense organs “upload” environmental data to the neurons in their brain, ….. with synaptic links for interconnectivity.

          Thus, ….. you are what your environment nurtures you to be.

      • Not too mention social calibration like “women and males.” I always ask male what? No one seems to understand the question. You can’t un-brainwash people.

  2. A subject’s compulsion to give the researcher what he/she is perceived as expecting is powerful and accounts for problematic results under hypnosis and quasihypnotic states, such as the “play therapy” used in the Manhattan Beach Preschool case.

  3. This is great! CAGW alarmists can now establish an illusionary new tier in their hierarchy – the Rubber Hand Club. Complete with their own secret hand shake.

  4. I think that politicians, ad men and activists are well aware of how much suggestion influences humans…

  5. Psychologists have long been aware of the dangers of ‘demand characteristics’ – in which subjects, often without realising it, say what they implicitly think they ought to say.

    This is the same reason polls can be made to say anything you want them to say … unless of course you’re trying to get valid data … in which case it’s darn hard to design a poll that actually tells you what people are really thinking. Once you’ve designed and trialed your poll, you probably have to hire people to administer the polls. Those people can really mess up your results if they aren’t properly trained.

    So, when you tell me that a psychological study messed up, well, I think that’s the norm.

  6. We’ve all heard the similar nonsense to power of suggestion.
    “I see climate change all around me.”
    “All I have to do is look out my window to see the climate crisis occurring right in front of me.”

    Easily manipulated people, living on emotions, combined with the power of suggestion.
    It has gotten too easy with the explosion of undeveloped critical thinking process, and a lack of real education in critical thought by schools and universities.

    Teenager Greta Thunberg anyone?
    Jane Fonda and others of her ilk, at the other end of the age spectrum?
    Undeveloped thinking, and emotion based reactions.

    • Students today are educated in critical thought.

      They see a ‘denier’ and immediately criticise.

      Though, just whether that constitutes thought is a moot point…

    • “All I have to do is look out my window to see the climate crisis occurring right in front of me.”

      “I look out my window to see that the climate crisis is bullshit”

    • What clinches it, experimentally (so to speak), is that even during the retrospectively-acknowledged warming hiatus, we had to watch journalists walking solemnly towards TV cameras and stating “you only need to look around to see it: things are heating up!”

      Of course this might just be false memory syndrome on my part (can anybody agree/disagree with my recollection?), so what I’d really like to see is a proper content analysis that asks: was the ‘control’ group (hiatus-era journalists) any more or less likely to report warming hallucinations than a warm-time group?

  7. Glad they waited a week to publish this. Otherwise, I would be highly suspicious of a study published by a Dr. Peter Lush so close to April 1, that has so little bearing on any real-life application or experience.

  8. In “Climate Science”, illusion is their reality. You need look no further than climate activists to find people highly influenced by suggestion.

    I had a few psychology classes in college – I remember even back then how shallow they were. “Children are ‘blank slates’ with little to no personality inherited from their parents” – how did they ever come to mistaken concepts? But they literally shunned and shamed you if you dared suggest otherwise. These “scientists” believed whatever the most influential crowd told them to believe, and that was the end of their thinking.

    Sound familiar?

    • It’s obvious to me, you can watch a pair of identical (genetically) twins, even as young as 18 mos., enter the room, and within 30 seconds you can identify which is which simply by the way they behave. Now if they’re being raised together then they’re undoubtedly treated the same, yet they behave differently, invariantly based on the personality type they were born with. And if they are genetically identical then their inherited personality characteristics should be identical as well. And yet they have different personalities from birth. Where does that come from? Until a psychologist can answer that question, all psychology is a crock.

    • Robert, I too had the same experience in college. My first day in college in an introduction to psychology class, in an enormous lecture hall with probably about two hundred kids, this goofy college professor gets up and claims that babies are born a blank slate and that all of human behavior can be explained by conditioning. He then proceeded to “explain” all of human behavior as the child grows up through reward and punishment. Even as a 17 year old I knew it was all pure nonsense. What I learned that day as a 17 year old was that a full professor of psychology at a major university could be totally ignorant of what it is to be human.

  9. “There is something fascinating about science. One gets such wholesale returns of conjecture out of such a trifling investment of fact.”
    Mark Twain

  10. I always thought the rubber hand illusion was about suggestion, so finding that the effect is stronger with more suggestible people is no surprise.

  11. Most climate science is but a rubber hand-puppet illusion.

    Researchers know what is expected and deliver it, as if being manipulated by an unseen hand shoved up them from below.

  12. There are obvious connections to implanted “False memory syndrome”. In the recent Cardinal Pell case the Police laid charges because the “victim”appeared to believe the impossible story with factual errors that he told. About 20 other witnesses said it was not possible for Pell to be there. Some were with him the whole time.

    • It helped that the far left ABC relentlessly attacked Cardinal Pell throughout the whole trial and the period leading up to it. They even tried to contaminate the High Court appeal by recycling false claims that had already been found not to be true, claiming that ‘new’ people had come forward.

      • The ONLY news outlet in Australia that provides at least a basic level of balanced reporting is Sky News. The ABC/SBS are extreme left, the others are less so but still left leaning.

        • Depends on the topic. Most of the time both the ABC and SBS sound like a mouthpieces for the US State Department to me.

        • Only someone with an extreme centrewards leaning would care about balance! Don’t bother pretending you’re not fanatically moderate, Patrick… I see you!

  13. Surely the time has come for us to use rubber hands when we want to shake hands, thus avoiding hand-to-hand transmission of covid.

    • During the black plague, hat tipping became the norm for greeting people as apposed to the Persian hand-shake. Today, it is very sad to see people not practicing basic hygiene in public places.

      People think Australia is a 21st century, first-world country, but let me tell you, many people think Africa is a dirty place, well, it is and it isn’t. Ethiopia for instance, you will not go in to a public place to drink or eat without first washing your hands. This is true too in private houses. It’s ceremonial almost and well established culturally and damn right rude if you object in any way.

  14. The power of a perceived authority figure to control what people think and do can be some scary stuff. The Stanley Milgram experiment is a classic. Volunteers willing to torture other volunteers as long as a person in a white lab coat said it was OK.
    People really need to stop worshiping scientists, but rather the quality and outcomes of the science the produce.

  15. I wonder what therapeutic implications this has for the phantom-pain patients Ramachandran reports having cured.

    For those unfamiliar with his work, Ramachandran pioneered the use of mirrors to give amputees “control” over non-existent body parts, thereby relieving years of suffering in some cases. For example, patients would complain of the sensation that their missing hand was locked into a permanent fist, resulting in spastic pain and the feeling of fingernails lacerating their palm. Ramachandran says he could simply put the patient in front of a mirror, ask them to un-clench their other (non-amputated) hand, and thus trick their brains into “relaxing” the phantom hand.

    • Ramachandran says he could simply put the patient in front of a mirror . . .

      I remember that one:

      • Nice find!

        That patient clearly didn’t *expect* the treatment to work. On the other hand (har har har), being drugged, tied up and forcibly experimented on by a home invader would probably give rise to some demand characteristics. 🙂

  16. It’s worth distinguishing agreeability from suggestibility.

    High-agreeability people are more likely to pretend to experience the illusion in order to make the experimenter happy.

    High-suggestibility people are more likely to experience the illusion, in which case it might be argued that it’s academic/meaningless to ask whether they “really” experience it or simply “think” they experience it. That’d be like trying to maintain that a placebo pill that relieves back pain isn’t “really” relieving back pain.

    My point is that even if the Rubber Hand Illusion were found to be entirely due to the subject’s expectations, it wouldn’t follow that it was any less interesting or less “real” a phenomenon.

  17. The ONLY news outlet in Australia that provides at least a basic level of balanced reporting is Sky News. The ABC/SBS are extreme left, some are less so but still left leaning, others are centre-left. So, 97% of Australians are brainwashed, anti-Trump, anti-BoJo (UK PM), anti-Shouty (Aussie PM), pro-climate change alarmist, “woke” and fall, hook line and sinker for almost all the media scare stories broadcast and published.

  18. No, Patrick. The problem is that the media, in general, have a left bias. The twidiots have a far left bias. Therefore anybody expressing sensible centre of the road sentiments gets shouted at and condemned as being far-right, racist, sexist, and probably many other -ist-isms. So they shut up and don’t give honest replies to polls or often write letters to the left leaning newspapers, knowing that such letters will not be published.

    This gives the impression that 97% of Australians are brain-washed, etc. Same in the UK and in the USA. Which is why the woke masses are gob-smacked when Trump wins, when Brexit wins and when Scomo wins.

    For benefit of Yanks ‘twidiot’ means a person who is idiot enough to send silly messages on Twitter (or believe them). Also called a ‘Twat’ though that usage is discouraged. ‘Scomo’ is a convenient abbreviation of the name of our Prime Minister, Scot Morrison. Rather like the abbreviation for your President – POTUS.

    • The whole media/political field is titled in favor of extreme left mantras (these mantras often not even policies, just mindless magically phrases).

      For example, who said “viruses don’t have passports, viruses don’t have visas” (so don’t dare imposing travel bans from region with thousands of cases of virus)?

      That inane soundbite could have been ushered by an extreme left, socialist, no border, brainwashed “orange man bad” liberal twitter “blue check”. But these claims were made by many people in the “libéral” (economically), pro-“free trade” world.

      Notably by people from LaREM (that’s Macron’s artificial party) elected representatives; notably https://twitter.com/RolandLescure elected to represent French citizens living in America, and his other soundbite about Coronavirus was to bash President Trump for … trying to distract from internal politics issues (which ones? the Bidens’ corruption?) with a travel ban.

      So don’t anyone dare saying that Macron’s party is not peddling far left crap. Also, a close adviser Ismaël Emelien to Macron helped elect… Nicholas Maduro in 2013.

  19. Well suggestion, hypnosis used to be called Mesmerism. The world renowned expert being Edgar Poe :
    THE FACTS IN THE CASE
    OF
    M. VALDEMAR.
    https://www.eapoe.org/works/tales/vldmard.htm
    “My attention, for the last three years, had been repeatedly drawn to the subject of Mesmerism; and, about nine months ago, it occurred to me, quite suddenly, that in the series of experiments made hitherto, there had been a very remarkable and most unaccountable omission: — no person had as yet been mesmerized in articulo mortis. ”

    Considering the facts of the case of the financial system, it does seem many have actually been so mesmerized…

  20. Now that the rubber hand illusion has been exposed as false. How long will it be before the rubber thermometer illusion also gets exposed?

  21. When I was a kid I dreamed I had a silver half dollar in my right hand, when I woke up I could still feel the silver half dollar in my right hand for a few seconds but no silver half dollar. Most of the time dream are forgotten on waking.

    The connection between mind and body is very real in many ways unknown but a good example is it tell you where to scratch when you itch. Sometimes the itch is in another place and you have to find it. The mind lets you see things that aren’t there such as color and shapes. You can look at deer facing you and not see it because you are looking for a side view. Camouflage is used to trick the eye into not seeing something there or seeing something that is not there. Netting might look like a small mound when it is actually covering a small communications site.

    Women do it all the time with makeup and clothes that enhance their appearance. And they look even better at closing time as in Mickey Gilley’s song Don’t the Girls all get prettier at closing time. The mind is also likely to be under the influence.

  22. If folk who’ve lost a hand still get feelings that the hand is there, surely it is reasonable that someone whose hand is hidden might react in the same way.

    • When I had to have surgery to repair my broken wrist, I foolishly agreed to a nerve block (never again). The creepiest thing (outside of carrying one’s arm around for 20 hours) was the “phantom limb” I experienced. Until the morning after the surgery, I had no idea the nerve blocked arm would even move. It laid by my side. I could feel an “arm” laying bent across my chest, the same position I carried the broken arm in, for the entire time. I could feel the fingers on it moving. Until my husband told me the actual fingers on my broken arm were moving, I had no idea. I believed the movement to be complete imaginary. I still could not connect the movement of the phantom limb to the real movement of the arm until the nerve block wore off and the illusion was gone. The phantom limb thing was not something anyone mentioned as possible and not something I would have ever imagined. You never know what your mind will come up with (It wasn’t “the drugs” because they don’t give you any good drugs anymore. This was just my mind shutting out the numb arm and creating a false arm to replace it.)

  23. From that reality, Olen, came the terms “Coyote Ugly” and “Double Coyote.”

    You wake up next to a girl. She is laying on your arm. She is so ugly that, rather than wake her up and face her, you chew off your arm. That’s Coyote Ugly.

    In the case that she is spectacularly ugly, to remind yourself to never do that again you chew off your other arm. That’s Double Coyote.

Comments are closed.