By IANS,
Sydney: Rats use their whiskers much like humans use their fingertips to feel objects as both of them process these sensations in the same part of the brain and in the same way, a new study says.
The finding may shed new light on how many animals use their vital sense of touch to make sense of the world around them, the study suggests.
“As nocturnal animals, rats use their whiskers much like the blind use walking sticks: to navigate their surroundings, localise objects and judge their size, shape and roughness,” says study co-author Ehsan Arabzadeh of the University of New South Wales (UNSW) School of Psychology’s Neural Coding Lab.
Rats depend on their whiskers even more than their eyes to “see” the world around them, much as bats use sound.
The study tested the responses of neurons in rat barrel cortex to tiny pulses of vibration to their whiskers, first using a series of regular pulses of the same intensity, then by irregular vibrations of slightly varying intensity.
They then tested student volunteers under similar conditions by exposing them to weak vibrations, felt through the tip of one index finger resting on a fine steel rod.
They found that rats use their whiskers much like humans use their fingertips to feel objects.
“For rats, the processing of touch through the whiskers is a highly efficient system and the whiskers have been shown by other researchers to be exquisitely sensitive,” says Arabzadeh, according to a UNSW release.
“They can be trained to detect incredibly tiny bumps and dents on the surface of a smooth object, at resolutions that are comparable to what we can manage with our sensitive fingertips,” he says.
“Our results with two such different species suggest that many other animals may perceive unpredictable sensory stimuli as being stronger than predictable ones. It’s one more piece in the puzzle of how our brains use sensory information to comprehend the physical world,” he concludes.
The findings were published in the Proceedings of the National Academy of Sciences.