Wearing a 'heart' on your sleeve can reduce stress -- ScienceDailyTo test the efficacy of doppel, the researchers exposed volunteers to a socially stressful situation and measured their physiological arousal and their reported anxiety levels. In a controlled, single-blind study, two groups of participants were asked to prepare a public speech -- a widely used psychological task that consistently increases stress. All participants wore the device on their wrist and a cover story was used to suggest to participants that the device was measuring blood pressure during the anticipation of the task. Importantly, for only one of the two groups of participants, the device was turned on and delivered a heartbeat-like vibration at a slower frequency than the participants' resting heart rate, while they were preparing their speech. The researchers measured both physiological arousal and subjective reports of anxiety. The use of doppel had a tangible and measurable calming effect across both physiological and psychological levels. Only the participants who felt the heartbeat-like vibration displayed lower increases in skin conductance responses and lower anxiety levels. "Wearable devices are becoming ubiquitous in everyday life, but across the board their primary aim is to quantify our activity. The results we got suggest that, rather than measuring ourselves, we can instead harvest our natural responses to heartbeat like rhythms in ways that can assist people in their everyday life." said Professor Tsakiris.