Navigation Links
Scientists create phantom sensations in non-amputees
Date:4/11/2013

The sensation of having a physical body is not as self-evident as one might think. Almost everyone who has had an arm or leg amputated experiences a phantom limb: a vivid sensation that the missing limb is still present. A new study by neuroscientists at the Karolinska Institutet in Sweden shows that it is possible to evoke the illusion of having a phantom hand in non-amputated individuals.

In an article in the scientific periodical Journal of Cognitive Neuroscience, the researchers describe a perceptual illusion in which healthy volunteers experience having an invisible hand. The experiment involves the participant sitting at a table with their right arm hidden from their view behind a screen. To evoke the illusion, the scientist touches the right hand of the participant with a small paintbrush while imitating the exact movements with another paintbrush in mid-air within full view of the participant.

"We discovered that most participants, within less than a minute, transfer the sensation of touch to the region of empty space where they see the paintbrush move, and experience an invisible hand in that position," says Arvid Guterstam, lead author of the study. "Previous research has shown that non-bodily objects, such as a block of wood, cannot be experienced as one's own hand, so we were extremely surprised to find that the brain can accept an invisible hand as part of the body."

The study comprises eleven experiments that explore in detail the illusory experience and include 234 volunteers. To demonstrate that the illusion actually worked, the researchers would make a stabbing motion with a knife towards the empty space "occupied" by the invisible hand and measure the participant's sweat response to the perceived threat. They found that the participants' stress responses were elevated while experiencing the illusion but absent when the illusion was broken. In another experiment, the volunteers were asked to close their eyes and quickly point with their left hand to their right hand (or to where they perceived it to be). After having experienced the illusion for a while, they would point to the location of the invisible hand rather than to their real hand.

The researchers also measured the brain activity of the participants using functional magnetic resonance imaging (fMRI). Perceiving the invisible hand illusion led to increased activity in the same parts of the brain that are normally active when individuals see their real hand being touched or when participants experience a prosthetic hand as their own.

"Taken together, our results show that the sight of a physical hand is remarkably unimportant to the brain for creating the experience of one's physical self," says Arvid Guterstam.

The researchers hope that the results of their study will offer insight into future research on phantom pain in amputees.

"This illusion suggests that the experience of phantom limbs is not unique to amputated individuals, but can easily be created in non-amputees," says the principal investigator, Dr. Henrik Ehrsson, docent at the Department of Neuroscience. "These results add to our understanding of how phantom sensations are produced by the brain, which can contribute to future research on alleviating phantom pain in amputees."


'/>"/>

Contact: Press Office at Karolinska Institutet
pressinfo@ki.se
46-852-486-077
Karolinska Institutet
Source:Eurekalert

Related medicine news :

1. Scientists solving the mystery of human consciousness
2. Scientists uncover multiple faces of deadly breast cancer
3. Scientists identify major source of cells defense against oxidative stress
4. Scientists tailor cell surface targeting system to hit organelle ZIP codes
5. Scientists rewrite rulebook on breast cancer in landmark global study
6. Warwick scientists uncover how checkpoint proteins bind chromosomes
7. NIH scientists link quickly spreading gene to Asian MRSA epidemic
8. Joslin scientists identify important mechanism that affects the aging process
9. Scripps Research scientists show how memory B cells stay in class to fight different infections
10. Scientists Map Melanomas Genome
11. A*STAR scientists discover switch to boost anti-viral response to fight infectious diseases
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:10/13/2017)... (PRWEB) , ... October 13, 2017 , ... ... locations throughout Arkansas that offers insurance and financial preparation services, is providing an ... Rock City Rescue organization. , Rock City Rescue is a locally recognized nonprofit ...
(Date:10/13/2017)... ... October 13, 2017 , ... The International Association of ... of excellence for the field of eating disorders, announces the opening of early ... in Orlando, Florida at the Omni Resort at ChampionsGate. , The ...
(Date:10/13/2017)... (PRWEB) , ... October 13, 2017 , ... Apple ... care services, staged a mock evacuation of the facility as part of a disaster ... Fire Department, Echo Hose EMS and Shelton City Emergency Manager, as well as the ...
(Date:10/13/2017)... (PRWEB) , ... October 13, 2017 , ... Global Healthcare ... scenic Alexandria Park in Milford, NJ. This free event, sponsored by Global Healthcare ... activity. The fun run is geared towards children of all ages; it is ...
(Date:10/13/2017)... ... October 13, 2017 , ... “The Journey: From the Mountains ... possible to save lost souls in the Philippines. “The Journey: From the Mountains to ... dedicated teacher of the Bible. She has taught all ages and currently teaches a ...
Breaking Medicine News(10 mins):
(Date:9/25/2017)... 2017   Montrium , an industry leader ... the IQPC Trial Master Files & Inspection Readiness ... EastHORN Clinical Services has selected eTMF Connect ... management. EastHORN, a leading European contract research organization ... transparency to enable greater collaboration with sponsors, improve ...
(Date:9/19/2017)... venture-backed medical device company developing a non-invasive, robotically assisted, platform therapy that uses pulsed sound ... ... Jim Bertolina, PhD ... Tom Tefft ... device executive Josh Stopek , PhD, who has led R&D and business development teams ...
(Date:9/12/2017)... NEW YORK , Sept. 12, 2017   EcoVadis , ... supply chains, has published the first annual edition of its Global CSR ... than 20,400 companies evaluated by EcoVadis, based on Scorecard Ratings that analyzed ... ... & Performance Index ...
Breaking Medicine Technology: