<qa>  How many participants will be tested in approximately 5 cohorts of 10 each?Fifty participants will be tested in approximately 5 cohorts of 10 each. After individual first lab visits, participants in each cohort will be randomized into two groups: two experimental groups. The experimental group will subsequently attend a group-based relaxation treatment based on mindfulness meditation principles. After this intervention, one of the experimental groups will use the biofeedback device in the next two weeks, whereas the other experimental group will not. To control for attention effects of the cueing messages that the biofeedback device sends out, the No-Biofeedback group will receive texts at regular intervals, however, these will not be tied to an individuals physiology. To control for the amount of attention in the waitlist group, a lab visit will be arranged where subjects receive general information about anxiety but not any practical treatment advice or exercises. 