Yoga Practice, Stress and Cognitive Performance

It has been indicated in recent research that Mindfulness-based interventions may offer possibilities of promoting human stress processing and reducing anxiety or depression. They also appear to positively influence cognitive performance. One mindfulness-based intervention next to a variety of others is yoga, a combination of physical, spiritual, and mental practices of Indian origin that arose to alleviate suffering and enhance psychological and physical well-being. The goal of the study is to find out how Hatha Yoga, the most common form of yoga, consisting of stretches, yoga postures and conscious breathing, affects emotional and cognitive processes. An essential part of yoga seems to be the increase of self-regulation and consequently the regulation of stress processing and of cognitive processes in general. Building on the Attentional Control Theory, it is hypothesized that anxiety and stress limit inhibitory function - the ability to block distracting, irrelevant information - and also impair the shifting of attention that normally accompanies smooth switching between different tasks and their processing requirements. In a randomized controlled trial with an experimental and a waiting group, the investigators aim to investigate whether active participation in a 60-minute hatha yoga class (intervention) at least three times a week for two months leads to less experienced stress and improves inhibition and attentional shifting. The intervention period with pre- and postmeasurements is expected to start in early January 2022 and end in December 2022. To measure the effect of the intervention, the investigators use three experimental test tasks, one each to examine inhibition function (here, measured by distractor interference in visual search), switching between different tasks or sensory modalities (here, collected by comparing performance after passagewise alternation vs. repetition of a sound vs. light discrimination), and alternation between different stimulus features (here, determined by comparing passagewise repetition vs. alternation of target stimulus color in visual search). In all of the experimental tasks, behavioral data (reaction times and error rates) and, in two, additional electrophysiological measures (event-related potentials) are collected using EEG. To investigate the role of stress the investigators use questionnaires as well as biological stress markers from saliva. In addition, participants will receive a link to questionnaires to complete by the start of the yoga intervention. On top, trait mindfulness will be examined as a potential mechanism underlying the effects of yoga practice on attention and stress. The subjects' trait mindfulness will be assessed by questionnaire as well.