the pleasure of touch, pleasure nerves, pleasure and pain studies

Scientists Learn More About the Pleasure of Touch

April 15, 2009 12:01 PM
by Cara McDonough
Researchers have discovered more about how and why people like to be touched, a discovery that could help explain sensations of pain, as well as certain aspects of human relationships.

Understanding Pain by Studying Pleasure

The team of researchers, which included scientists from the University of Gothenburg in Sweden, the University of North Carolina and the Unilever company, identified a type of nerve fiber in the skin that sends pleasure messages. They also discovered that people had to be stroked at a speed of 4-5 cm. per second to activate the pleasure sensation.

Why are the findings so important? Not only because they could help explain how “touch sustains human relationships,” according to the BBC, but because specific information on pleasure sensations can actually help explain pain.
One experiment involved stroking a person’s forearm at different speeds. Professor Francis McGlone, who worked on the study, said the speed that people found pleasurable was the same speed that a mother would use to stroke her baby, or that couples use to express affection.

"We believe this could be Mother Nature's way of ensuring that mixed messages are not sent to the brain when it is in use as a functional tool,” he said.

The research may help scientists learn more about what causes—and how to treat—conditions such as peripheral neuropathy, which occurs when the peripheral nervous system is damaged, and can stimulate a sensation of pain even when there is no cause.

Other recent scientific findings could also help in diagnosing and treating neuropathy and other conditions. A new method developed by Massachusetts General Hospital (MGH) could help better define the pain that patients feel, thus leading to better treatments, ScienceDaily reports.

The method, called Standardized Evaluation of Pain (StEP), is comprised of a set of 6 questions and 10 physical tests that help discriminate between neuropathic and nonneuropathic pain.
"The treatment of neuropathic and nonneuropathic pain is quite different, and if a diagnosis is wrong, patients may receive treatment, including surgery, that does not improve their pain,” said Joachim Scholz, MD, of MGH’s Anesthesia and Critical Care department.

Related Topic: The mystery of itching

Researchers also recently made some important discoveries about how scratching relieves itching. Dr. Glenn Giesler and a research team at the University of Minnesota released a study showing what happens when primates scratch the spinothalamic tract, an area of the spinal cord thought crucial to perception of itchiness, and found that it halted transmission of itch signals to the brain.

Pain also played a part in their research. The study showed that scratching helps relieve itching by reducing pain sensations transmitted to the brain, a crucial finding that could lead to new treatments for chronic itching.

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