This research investigates whether a short mindfulness exercise can reduce children’s psychophysiological stress reactions in the face of a performance task. To answer the question, a randomized controlled trial with 106 elementary school children, aged between 5 and 11 years, was conducted. An intervention group completed a two-minute breathing exercise, whilst a comparison group watched a short video, before both groups performed a stress-evoking Stroop test. The stress levels of both groups were measured via galvanic skin response and compared. It was hypothesized that the comparison group would show a higher stress reaction during the stress-evoking task than the intervention group. Contrary to the hypothesis, results show that the intervention group had a higher psychophysiological stress reaction during the task than the comparison group. However, the stress reaction to the announced difficulty of the task was smaller in the mindfulness group than in the comparison group. Results are discussed based on different theoretical mechanisms of mindfulness. Directions for future research include the use of different techniques and durations of mindfulness interventions, different control group activities and stress-test operationalizations, as well as the distinction between age groups.

The emotions experienced by primary school students have both positive and negative effects on learning processes. Thus, to better understand learning processes, research should consider emotions during class. Standard survey-based methods, such as self-reports, are limited in terms of capturing the detailed trajectories of primary school  children’s emotions, as their abilities of self-reporting are developing and still limited. Emotions can also be tracked by capturing emotional responses as they occur e.g. from physiological reaction measured with sensor wristbands. This technology generates an emotional responsestypology based on continuously captured physiological data, such as skin conductivity and skin temperature. However, such measurement methods need to be validated before being used. The present study thus attempted to validate this instrument with primary school students. We used the BM Sensor Wristband technology, as its emotional response typology is based on the categorical emotion and homeostasis approach. In our research, we focus on the emotional responses that can be distinguished by the BM Typology and that can influence learning processes. These emotional responses are: “joy”, “curiosity”, “attention”, “fear”, “anger” and “passivity”. Therefore, we induced emotional responses in primary school children through specifically developed audio-visual stimuli. Using logistic mixed effects modelling, we investigated the occurrence of opposing reactions. We observed that primary school children’s reactions to audio-visual stimuli could be differentiated. We conclude that primary school children’s emotional responses, such as “joy”, “curiosity”, “attention”, “fear”, “anger” and “passivity”, can be accurately measured by evaluating physiological data.