JAKARTA – The skin is a largest organ in the human body which envelops humans from head to toe and allows us to touch, feel and interact with the outside world. But there is one part of the skin that is more sensitive to even recognizing objects around us.
A new study has revealed how receptive the sensory neurons are in human fingers. We can even detect touch on a very small scale from a single skin on the tip of a finger. (Read: Archaeologists Find 5 Century BH, Netizens in Uproar)
“You would expect that a single papillary ridge (fingerprint) would play a role, but it hasn’t been shown before,” Ewa Jarocka, co-author of the study from Umeå University in Sweden, told The Guardian.
Sensory neurons attached to receptors dotted just below the surface of the skin, enabling us to detect touch, vibration, pressure, pain, and more. Our own hands contain tens of thousands of neurons, each with receptors in a small surface area of the skin, called a receptive field.
To map these fields, para researchers examined 12 healthy people with a special tool designed by scientists. A machine then moved a small, 0.4 millimeter-wide cone about 7mm across the skin and the team recorded the response of each neuron using electrodes on the participants’ arms. (Also read: Prevent Repeating Crime, Recidivists Will Be Installed with a GPS Bracelet)
In particular, they mapped the more sensitive zones known as subfields in this receptive field. By calculating the detection area of the sensory neurons and mapping it to fingerprints, the team found that the width of the detection area was equivalent to the width of one fingerprint ridge.
This subfield also does not move when the machine rotates the dots faster or slower, or changes direction, indicating that this sensitive area is anchored to the part of the fingerprint itself.
“We report that the sensitivity of the subfield arrangement for both neuron types corresponds to a spatial period of 0.4 mm and provides evidence that the spatial selectivity of the subfields arises because the associated receptor organ measuring mechanical events is limited to a single papillary ridge,” write the researchers in the paper their new.
Interestingly, this is first study which shows that fingerprints help us more accurately perceive the world around us. “We have all those multiple hotspots, and each one responds to the 0.4 millimeter breakdown, which is the approximate width of the fingerprint,” Jarocka told New Scientist. (Also read: This Scientist Explains What Really Happens When Humans Die)
“Then our brains take in all that information. It really offers an explanation for how it is possible that we are so agile and have such high sensitivity at our fingertips,” he said.
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