Our hands have a sense of touch that's important for how we view and interact with the world. Now, scientists have categorized the pattern of vibrations on our skin that allow us to feel what we're touching.
"Most people don't have a very clear picture of how touch sensation actually arises," said Yon Visell, UC Santa Barbara faculty member and one of the researchers.
When your arm or leg falls asleep, it becomes numb. This makes you hesitant to use these appendages to walk or lift things, but why is this? A sense of touch plays a huge role in how we, as humans, interact with the world.
But the feeling of numbness doesn't apply to everything. For example, people who have had their fingers anesthetized are still able to feel surface detail. Knowing this, the researchers wanted to investigate the sense of touch a bit more closely.
"How do those signals reflect what it is that we're doing and what it is we're touching? Do parts of the hand nearer to the wrist receive significant information about the shape of the object that we're touching, what it's composed of, or how we're touching it? How are different parts of the hand involved in touch sensing?" Visell said. "It is possible that the hand, like the ear, is able to use vibrations produced through contact in order to infer what is being touched, and how the hand is touching it."
In this latest study, the researchers used tiny accelerometers. These are vibration sensors that the volunteers wore on the sides and backs of their fingers and hands. This allowed the researchers to capture, catalog and analyze patterns of vibrations in the skin of the whole hand that were produced during active touch.
So what did they find? The vibrations that are created through touch depend on the type of action and the object being manipulated. This means that people's sense of touch is refined and allows them to determine what type of object they're working with even without seeing it.
The findings reveal a bit more about the sense of touch. More specifically, they show how vibrations that we sense are crucial for learning more about the world around us.
The findings are published in the March 2016 journal Proceedings of the National Academy of Sciences.
