Sensory illusion study provides new insight for body representation brain disorders

Is this my finger?

2013-09-23

(Press-News.org) People can be easily tricked into believing an artificial finger is their own, shows a study published today [23 September] in The Journal of Physiology. The results reveal that the brain does not require multiple signals to build a picture body ownership, as this is the first time the illusion has been created using sensory inputs from the muscle alone.

The discovery provides new insight into clinical conditions where body representation in the brain is disrupted due to changes in the central or peripheral nervous systems e.g. stroke, schizophrenia and phantom limb syndrome following amputation.

Professor Simon Gandevia, Deputy Director of Neuroscience Research Australia (NeuRA), says: "It may seem silly to ask yourself whether your index finger is part of your body. However, our current findings demonstrate that this question has led to important insights into key brain functions.

"These findings could lead to new clinical interventions where the addition or the removal of specific sensory stimuli is used to change someone's body image."

In the experiment, subjects held an artificial finger with their left hand that was located 12 cm above their right index finger. Vision was eliminated and anaesthesia was used to numb the skin and remove feelings of joint movement. When the artificial finger and the right index finger were moved synchronously, subjects reported they were holding their own index finger: the brain incorrectly incorporated the artificial finger into its internal body representation.

The human brain uses sensory signals to maintain and update internal representation of the body, to plan and generate movements and interact with the world. The study gives new understanding as to how the brain decides what is part of our own body and where it is located. Contrary to previous theories which used multiple sensory inputs including touch and vision, these results demonstrate that messages coming from muscle receptors are enough to change the internal body representation.

The team additionally found a new type of sensory 'grasp illusion' in which perceived distances between index fingers decreases when subjects hold an artificial finger. This implies that the brain generates possible scenarios and tests them against available sensory information. Professor Gandevia says: "Grasping the artificial finger induces a sensation in some subjects that their hands are level with one another, despite being 12 cm apart. This illusion demonstrates that our brain is a thoughtful (yet at times gullible!) decision maker: it uses available sensory information and memories of past experiences to decide what scenario is most likely (i.e. 'my hands are level')."

### END

ELSE PRESS RELEASES FROM THIS DATE:

Targeting memory T-cells in Type 1 diabetes

2013-09-23

WA, Seattle (September 23, 2013) – Encouraging results from the T1DAL study (Targeting effector memory T cells with alefacept in new onset type 1 diabetes), led by Mark R. Rigby M.D., Ph.D. from Indiana University and Riley Hospital for Children in Indianapolis and sponsored by the Immune Tolerance Network (ITN) with additional support from JDRF, are published today in The Lancet Diabetes & Endocrinology. Alefacept, an engineered fusion protein targeting a surface molecule, CD2, found on T-lymphocytes, was the first biologic therapy approved for moderate to severe plaque ...

A boost for cellular profiling

2013-09-23

New York, NY and Stockholm, Sweden -- A team of researchers affiliated with Ludwig Cancer Research and the Karolinska Institutet in Sweden report in the current issue of Nature Methods a dramatically improved technique for analyzing the genes expressed within a single cell -- a capability of relevance to everything from basic research to future cancer diagnostics. "There are cells in tumors and in healthy tissues that are not present in sufficient numbers to permit analysis using anything but single-cell methods," explains senior author, Rickard Sandberg, PhD. "This method ...

Calming fear during sleep

2013-09-23

CHICAGO --- A fear memory was reduced in people by exposing them to the memory over and over again while they slept. It's the first time that emotional memory has been manipulated in humans during sleep, report Northwestern Medicine® scientists. The finding potentially offers a new way to enhance the typical daytime treatment of phobias through exposure therapy by adding a nighttime component. Exposure therapy is a common treatment for phobia and involves a gradual exposure to the feared object or situation until the fear is extinguished. "It's a novel finding," ...

UCLA scientists explain the formation of unusual ring of radiation in space

2013-09-23

Since the discovery of the Van Allen radiation belts in 1958, space scientists have believed these belts encircling the Earth consist of two doughnut-shaped rings of highly charged particles — an inner ring of high-energy electrons and energetic positive ions and an outer ring of high-energy electrons. In February of this year, a team of scientists reported the surprising discovery of a previously unknown third radiation ring — a narrow one that briefly appeared between the inner and outer rings in September 2012 and persisted for a month. In new research, UCLA ...

USC scientists ID protein that regulates cellular trafficking, potential for anti-cancer therapy

2013-09-23

LOS ANGELES — Molecular microbiologists at the University of Southern California (USC) have uncovered intricate regulatory mechanisms within the cell that could lead to novel therapeutics for the treatment of cancer and other diseases. Their findings, which have long-standing significance in the basic understanding of cell biology, appear in the journal Nature Cell Biology. "Our research reveals a new regulatory mechanism that coordinates two distinct intracellular processes that are critical to cellular homeostasis and disease development," said Chengyu Liang, M.D., ...

Scientists closer to universal flu vaccine after pandemic 'natural experiment'

2013-09-23

Scientists have moved closer to developing a universal flu vaccine after using the 2009 pandemic as a natural experiment to study why some people seem to resist severe illness. Researchers at Imperial College London asked volunteers to donate blood samples just as the swine flu pandemic was getting underway and report any symptoms they experienced over the next two flu seasons. They found that those who avoided severe illness had more CD8 T cells, a type of virus-killing immune cell, in their blood at the start of the pandemic. They believe a vaccine that stimulates ...

The brain cannot be fooled by artificial sweeteners

2013-09-23

The results of the new study imply that it is hard to fool the brain by providing it with 'energyless' sweet flavours. Our pleasure in consuming sweet solutions is driven to a great extent by the amount of energy it provides: greater reward in the brain is attributed to sugars compared to artificial sweeteners. Professor Ivan de Araujo, who led the study at Yale University School of Medicine USA, says: "The consumption of high-calorie beverages is a major contributor to weight gain and obesity, even after the introduction of artificial sweeteners to the market. We believe ...

Creating electricity with caged atoms

2013-09-23

A lot of energy is wasted when machines turn hot, unnecessarily heating up their environment. Some of this thermal energy could be harvested using thermoelectric materials; they create electric current when they are used to bridge hot and cold objects. At the Vienna University of Technology (TU Vienna), a new and considerably more efficient class of thermoelectric materials can now be produced. It is the material's very special crystal structure that does the trick, in connection with an astonishing new physical effect; in countless tiny cages within the crystal, cerium ...

Propofol discovery may help lead to development of new anaesthetics

2013-09-23

New research on the most commonly used anaesthetic drug could help to unravel a long-standing mystery about how it induces a pain-free, sleep-like state. General anaesthetics are administered to tens of millions of people every year in hospitals, where they are used to sedate patients undergoing surgery. Despite this, scientists have yet to understand how the drug interacts with its targets in brain cells to achieve this effect. Following years of research on propofol, which has become the most commonly used anaesthetic since it was introduced in the 1980s, researchers ...

Propofol discovery may aid development of new anesthetics

2013-09-23

Researchers at Washington University School of Medicine in St. Louis and Imperial College London have identified the site where the widely used anesthetic drug propofol binds to receptors in the brain to sedate patients during surgery. Until now, it hasn't been clear how propofol connects with brain cells to induce anesthesia. The researchers believe the findings, reported online in the journal Nature Chemical Biology, eventually will lead to the development of more effective anesthetics with fewer side effects. "For many years, the mechanisms by which anesthetics act ...

Sensory illusion study provides new insight for body representation brain disorders

ELSE PRESS RELEASES FROM THIS DATE:

LAST 30 PRESS RELEASES: