Although there are things we can do to reduce feelings of stress, most involve temporarily stopping what we're doing – which isn't always possible. A new study, however, suggests that the automated brushing of hairy skin is an effective form of passive stress reduction.
Past research has shown that activities like meditation and breathing exercises can lessen levels of perceived stress and anxiety. The problem is, if someone is busy at their job or some other demanding obligation, it may be quite difficult for them to stop and perform such activities.
With this problem in mind, scientists have previously looked into passive stress-reduction techniques – these don't require the person to consciously do anything themselves.
One such technique, known as affective touch, involves repeatedly stroking an area of hairy skin on the person's arm. While it has proven to be effective, past experiments have used volunteers to manually stroke the skin of test subjects with a handheld soft brush. Needless to say, such an arrangement wouldn't be very doable in real-world scenarios.
Led by Prof. Tanzeem Choudhury, scientists at Cornell University recently set out to see if the same effect could be produced by a mechanized wearable device. The gadget that they created is worn on top of the forearm, and uses springs and an electric actuator to slowly move a piece of synthetic fur back and forth along the skin.
For the single-blind study, a total of 24 volunteers wore the device while performing an adapted version of Trier Social Stress Test, which consists of a series of stressful cognitive tasks. The device was activated while a treatment group of 12 participants took the test, but was switched off while a control group of the other 12 did so. Both groups subsequently got to experience the brushing sensation, after the stress test had been completed.
It was found that while physiological responses such as heart rate were the same for both groups throughout the experiment, the treatment group reported approximately 50% lower levels of perceived stress and anxiety while they were actually performing the cognitive tasks. This outcome falls in line with that of previous studies, in which hand-operated brushes were used.
So, why does either type of brushing even work in the first place?
"The key reason is that brushing hairy skin activates a type of mechanoreceptor, C tactile," Cornell researcher Yiran Zhao tells us. "C tactile is responsible for social touch: we evolve C tactile to communicate emotions with each other. C tactile also activates the reward circuit in the brain and creates innate pleasantness. Together, the pleasantness and emotional support helped the receiver perform emotion regulation and calm down."
And while the device used in the experiment may look a bit clunky, Zhao states that future research could focus on methods of producing something with a more wearable form factor.
A paper on the study – which also involved scientists from Stanford University, the University of Chicago and Georgia Tech – was recently published in the journal Proceedings of the ACM on Interactive, Mobile, Wearable and Ubiquitous Technologies.
Source: Cornell University
