The Influence of Hatha Yoga Practice on Stress and Cognitive Performance
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 98
- 试验地点
- 2
- 主要终点
- Change in switching between Attentional Control Sets
研究概览
简要总结
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.
详细描述
Main goals of the study and hypotheses
- What is the effect of hatha yoga on switching between tasks or sensory modalities (e.g., processing times when switching from tone to light discrimination across tasks compared to when switching from tone to light discrimination across tasks) and between features (e.g., processing times when switching from red to green target stimuli across tasks compared to when switching from red to green target stimuli across features)? The investigators hypothesize that yoga practitioners (intervention group) will show lower switching costs and lower error rates than the control group (waiting group). 2) How does hatha yoga affect the inhibition function of attention? The investigators expect increased inhibition of salient distractors (e.g., green distractors among otherwise red stimuli) during visual search (e.g., for a shape-defined target stimulus in the set of red stimuli per display) in the intervention group compared to the control group (indexed by event-related potential PD on the distractor) or lower attraction of attention by distractors (indexed by reduced N2pc on the distractor). The investigators also expect a lower rate of false alarms and a higher rate of hits in visual search performance in the intervention than in the control group. 3) What is the effect of hatha yoga on the stress and anxiety levels of the subjects? The investigators expect lower cortisol and alpha-amylase levels in the intervention group compared to the control group as well as lower levels of subjectively reported stress and reported anxiety as indicated by corresponding questionnaire scores in the intervention group compared to the control group. 4) What is the effect of Trait Mindfulness on stress parameters in the context of yoga intervention? The investigators expect that Trait Mindfulness acts as a moderator and that an increase in Trait Mindfulness during the intervention also leads to increased stress reduction.
Power analysis and recruitment strategy
Based on a power analysis with d = 0.5, 80% power and 5% alpha error, a sample size of 102 subjects is targeted, increasing to 122 with the expected dropouts of 20%. Potential participants will be made aware of the study via social media (Facebook, Instagram) and on campus via promotional materials.
Detailed description of data assessment and study materials
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Other
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 40 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •healthy individual without mental or neurological disorder or disease
- •18-40 years
排除标准
- •Insufficient comprehension of the German language
- •Current mental or neurological disorders (except eating disorders)
- •Current or regular yoga practice in the past
- •Uncorrected visual or auditive impairment
- •Scull fractures or head concussions within the last 6 weeks
- •Non-existence of a vaccination or convalescence certificate of COVID-19
结局指标
主要结局
Change in switching between Attentional Control Sets
时间窗: Baseline plus 8 weeks
Switching between Attentional Control Sets will be measured by switching costs, meaning longer response times (RTs) for trial-by-trial switches than repetitions of a task, and hit rate. Both variables will be combined to assess the change in ability to switch between processing different features which is expected in the intervention group in comparison to the waiting control group.
Change in task switching between modalities
时间窗: Baseline plus 8 weeks
Task switching between modalities will be measured by speed regarding switches between modalities and error rate in the respective (auditive and visual) modalities. The ability to switch between different modalities is expected to have changed in the intervention group in comparison to the waiting control group. Switching speed will be analyzed by using steady-state visual evoked potentials and auditory steady-state potentials (both measured with EEG) with tagged frequencies. Switching speed and error rate will be combined to report task switching ability between modalities.
Change in inhibition function
时间窗: Baseline plus 8 weeks
Inhibition function will be measured by response time, hit rate and number of false alarms. In addition, dependent electrophysiological variables will be the mean amplitudes of two event-related potential components, named N2-posterior contralateral (N2pc) and distractor positivity (Pd). Named variables will be combined to assess the change in inhibition function that is expected in the intervention group vs. the control group.
Change in attention shifting
时间窗: Baseline plus 8 weeks
Attention shifting will be measured by an event-related potential named N2-posterior-contralateral (N2pc) with EEG. When target-similar items are processed, N2pc should be different in the intervention group than in the control group.
Change in self-reported stress
时间窗: Baseline plus 8 weeks
Self-reported stress will be measured with the Perceived Stress Scale (PSS), ranging from 0 to 40 points, with higher scores indicating higher perceived stress.
Change in physiological stress
时间窗: Baseline plus 8 weeks
Physiological stress levels will be measured by biological markers (cortisol and alpha-amylase). Both are expected to have changed in the intervention group in comparison to the waitlisted control group, indicated by changed cortisol levels as well as changed alpha-amylase concentration. Both cortisol and alpha-amylase levels will be combined to report physiological stress.
Change in self-reported anxiety
时间窗: Baseline plus 8 weeks
Self-reported anxiety will be measured with the State-Trait-Anxiety Inventory (STAI) form Y, ranging from 20 to 80, with higher scores correlating with higher anxiety. Self-reported anxiety is expected to have changed in the intervention group in comparison to the waitlisted control group.
次要结局
未报告次要终点
研究者
Bence Szaszkó
Principal Investigator
University of Vienna