In an effort to enable blind people to navigate their surroundings more safely and effectively, researchers at Israel’s Weizmann Institute of Science have drawn inspiration from an unexpected source: rat whiskers.
The team of scientists, led by Prof. Ehud Ahissar and Dr. Amos Arieli, enrolled human volunteers to wear blindfolds and a flexible plastic “whisker” of 30 cm (almost 12 inches) in length, which was attached to the index finger and sported position and force sensors on its base. The volunteers employed the whiskers to perform location tests, in which they were required to discern which of two previously-placed poles was positioned farther away from themselves.
The subjects took to the challenge so well that on the first day alone, they were able to identify the correct pole, when it was positioned further back from its counterpart by only 8 cm (3 inches). An analysis of the data gleaned from the research showed that the volunteers were able to do this by noting which whisker made contact with the pole first.
Once the test was repeated the following day, the average sensory threshold was reduced to just 3 cm (1 inch), with some volunteers able to sense a displacement in the poles of as little as 1 cm (0.4 inch). However, in the interim, the ability of the volunteers to sense time differences had not improved, but rather, they had improved their whisking technique, and by slowing down their hand motions, the subjects could thus sense a smaller spatial difference.
“We know that our senses are linked to muscles, for example ocular and hand muscles. In order to sense the texture of cloth, for example, we move our fingers across it, and to seeing stationary object, our eyes must be in constant motion,” explained Dr. Avraham Saig, who took part in the research. “In this research, we see that changing our physical movements alone – without any corresponding change in the sensitivity of our senses – can be sufficient to sharpen our perception.”
The scientists state that the research could lead to the development of small devices worn on the hands, which translate video input to mechanical stimulation and provide blind users with an intuitive sensory aid.
The findings of the study were recently published in the Journal of Neuroscience.
Source: Weizmann Institute of Science