The science of scratching: Why don't you tickle yourself?

, June 9, 2020 /PRNewswire/ --Bio ValleyBIOON/-- Have you ever tried to tickle yourself? Next time you have a private time, try it - you'll find it's almost impossibleWith our fingers swinging a few times properly, most of us can let our children, friends and even animals like mice giggleThe reason why we can't do the same thing on ourselves has always been a mystery, but now we may be closer than ever to solving this problemUnderstanding that it requires an in-depth understanding of how the brain works; the science of scratching is surprisingly complex for such an interesting activitythe first thing we can understand about us not to tickle ourselves is that this is just an example of a common phenomenon: humans react differently to touch, depending on whether the feeling is created by ourselves or by something elseIf you pat your hand and then let someone else clap your hand with their hands, you usually think the latter is strongerOur cognitive differences in ourselves and other things in our surroundings are not limited to humans, nor to touchIn 2003, a study showed that crickets felt quieter than other crickets"Froman evolutionary point of view, it makes sense to have this ability," said Dr Konstantina Kilteni of the Karolinska Institute in Stockholm, SwedenIt is useful to know whether a feeling is worth paying attention toIf your arm is full of bugs, you'll certainly notice"
body ownership
the premise is that our brains have a sense of body ownership so that we know whether the touch comes from our own moving fingers or from some kind of foreign object Understanding how this works may be a key part of mastering itching Dr Kilteni says that in the late 1990s, there was a lot of research that began to explore the issue, but while they established a link between touch intensity and the source of touch, they did not explore the exact conditions for such a link In 2017, she started the "Tickle Me" project one of her key experiments involves observing how people use a clever set of levers to perceive finger touch In the first part of the experiment, people touch a lever with their left index finger and immediately trigger the second lever to touch the right index finger Dr Dr Kilteni then compared it to two other ways In the first experiment, they placed their left finger on a plate above the first lever, and the plate was removed, leaving their fingers on the lever This triggers a second lever to touch the finger of the right hand, but crucially, it is involuntarily In the last change, the finger of the right hand is touched by levers and does not require any input from the person at all As a result, it is thought that the touch generated by these three methods is stronger in turn, although they are all produced with the same force This suggests that if the brain knows that touch is coming, it feels less intense 'One of the reasons we can't tickle ourselves is that our brains are ready,' Dr Kilteni said in another experiment using the same lever, Dr Kilteni also used a clever twist that delayed participants by a fraction of a second before touching the first lever with one finger This unexpected factor has proved important: delay makes the feeling stronger All of this gives us another hint of why it's so hard to tickle yourself: when you scratch, it's hard not to be found Dr Kilteni has conducted a number of experiments, but perhaps the most telling article came a few months ago, focusing on this area of the brain called the body's sensory cortex, the part of the brain that receives sensory information about the body in an experiment, she asked 30 volunteers to touch their index fingers together, then had the robots touch their fingers, and she scanned their brains using a functional MAGNETIC resonance imaging machine Some people seem to think that self-touching is not as strong as others, and Dr Kilteni can see that these people tend to have a stronger connection between the body's sensory cortex and another region of the brain, the cerebellum the cerebellum the cerebellum, located at the back of the neck It is at the heart of our physical motor control, but it is also thought to play a vital role in monitoring cognition Think of the brain as a factory where different parts process different pieces of information, and the cerebellum is the supervisor of quality control Neuroscientists suspect that when our own fingers, not someone else's fingers, are working, the cerebellum sends signals that reduce the body's sensory cortex's perception of scratching Dr Kilteni's fMRI study confirms this hypothesis , Dr Marlies Oostland, of New Jersey, USA, is planning to explore this link further through her NeuroTick project Professor Michael Brecht of the Bernstein Center for Computational Neuroscience at Humboldt University in Berlin, Germany, is one of Oostland's project mentors In 2016, he and his colleague Dr Shimpei Ishiyama found that mice were itchy They found that when mice were tickled, they gave off an ultrasonic "laugh" while their bodies felt the cortex lit up like a Christmas tree when Oostland visited Berlin, she didn't just tickle the mice "I'm used to dealing with rats, so I'm too gentle You have to rough up the rats and make them laugh; picture source: Ph.D began her project at Princeton University to conduct basic research on how the cerebellum of mice predicts animal movements
She is using a probe to measure the activity of individual cells in the mice's cerebellum to see what happens in their brains when she blows at their beards (which is not unpleasant, but should be surprising) based on this understanding, she plans to travel to Professor Brecht's lab in Germany in two years to study the link between the cerebellum and the body's sensory cortex, and to try to determine whether and how the signals are transmitted between the two Dr Oostland says such research will not only help us better understand the most complex object in the universe-- the human brain-- but also help us better understand autism spectrum disorders People with cerebellum injuries shortly after birth are 36 times more likely to develop autism later in life We don't fully understand why, but Dr Oostland says basic research like this could help (BioValleyBioon.com) References: 1
The Science of the ticking: What brain won't't let us tickle ourselves 2
Corolla Discharge Inhibition of Ascending Auditor-Daniels in The Stridulating And unlearning of the predicted sensory delays in self-generated touch
5 Efference Copy Is Hasfor the Attenuation of Self-Generated Touch
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Self and others in the sensorimotor system: asauaadady ossy datsy