Primary school students suffer from high levels of anxiety and stress. Having emotional regulation abilities can help them to manage challenging emotional situations. Conscious and slow breathing is a physiological, emotional regulation strategy that is feasible for primary school students to learn. Following Polyvagal Theory and PMER Theory, this research presents the results of a breath-focused heart rate variability biofeedback intervention. The intervention aimed to reduce anxiety and physiological and social stress in primary school children. A total of 585 students (46.4% girls and 53.6% boys) from the same public school, aged between 7 and 12 years (M = 8.51; SD = 1.26), participated in this study. To assess the impact of training, a mixed design was used with two groups (Treatment and Control groups), two evaluation phases (Pretest and Post-test), and three educational cycles (first, second and third cycles). To examine heart rate variability, emWave software was used and anxiety and social stress were measured by the BASC II test. The results showed that after the intervention, the students learned to breathe consciously. Moreover, they reduced their levels of anxiety (M(SD)_pretest = 12.81(2.22) vs. M(SD)_posttest = 13.70(1.98)) and stress (M(SD)_pretest = 12.20(1.68) vs. M(SD)_posttest = 12.90(1.44)). The work also discusses the limitations and benefits of this type of intervention in primary schools.

This study investigated the benefits of using a biofeedback intervention programme to train children in controlling their heart rate variability (HRV) through slow-paced breathing in real time. HRV biofeedback interventions focused on showing subjects to breathe such that their HRV numbers rise, improving their self-regulation. The HRV biofeedback intervention, focused on breathing, was conducted with primary education students aged between 7 and 11 years. The programme consisted of five biofeedback sessions, where students were taught to breathe six long and slow pairs of breaths per minute, to increase their HRV. After participation in the programme, students, regardless of gender, increased their HRV in a statistically significant fashion with a large effect, but this effect was not the same for all ages. HRV biofeedback interventions are rarely applied in schools and given the effectiveness of the intervention to improve HRV in children, the applied implications of our results in educational settings are discussed, especially taking into account the children’s ages.

Objectives: Mindfulness consists of paying attention to the present moment with curiosity, acceptance and non-judgment. Although several instruments exist for evaluating mindfulness in adults, few have been adapted for children, and even fewer have been adapted to the Basque language. The aim of the present study is to adapt the Reduced Kentucky Inventory of Mindfulness Skills (KIMS-R) questionnaire for use with Basque-speaking children. Method: A total of 479 children from the last 2 years of primary education (Years 5 and 6), aged between 9 and 12 years, participated in this study. The sample was divided into two subgroups: exploratory subsample (n = 237) and confirmatory subsample (n = 242). In addition to the KIMS-R, we also administered other questionnaires to measure mindfulness, perceived stress, emotional skills, neuroticism and depression. Results: The analysis showed that the adapted questionnaire was reliable, with scores measuring consistency and stability in acceptable ranges. The analysis revealed a 5-factor structure (Internal observation, External observation, Description, Acting with awareness and Acceptance without judgment). These dimensions showed acceptable internal consistency (α between 0.69 and 0.83; ω between 0.69 and 0.83) and temporal stability (r = 0.54, 0.64, 0.79, 0.40, 0.59). The instrument was also found to have adequate external validity, with associations being observed between mindfulness and emotional abilities, perceived stress, neuroticism and depression. Conclusions: The Basque version of the KIMS-R will enable scholars to assess the ability of children in the Basque Autonomous Community to be mindful. It will also be useful for evaluating the effectiveness of interventions designed to promote mindfulness skills. This adaptation of the KIMS-R instrument can be considered a step forward in the field of mindfulness research. Preregistration: This study is not preregistered.

Emotion regulation is essential for psychological development, and mindfulness has shown promise in enhancing emotional, cognitive, and physiological outcomes. However, traditional mindfulness practices can be challenging for children. Virtual reality offers an engaging platform to improve adherence, but its impact on children remains underexplored. This study aimed to assess the effectiveness of a short virtual reality-based mindfulness programme in improving heart rate variability and emotional skills in primary school children. The study involved 127 children aged 9–12 years (Years 5 and 6). Heart rate variability, a biomarker of autonomic nervous system activity, was measured across four virtual reality mindfulness sessions, while emotional skills were assessed pre- and post-programme. Results showed significant heart rate variability improvements, with increased high frequency power and physiological coherence indicating enhanced parasympathetic activity, relaxation, and emotional regulation. Although low frequency power decreased significantly after the first session, its interpretation as a marker of sympathetic activity remains controversial, warranting cautious analysis. In addition, the intervention improved emotional skills, particularly emotional clarity and the ability to repair emotions. Younger children (Year 5) showed greater heart rate variability gains than older peers, likely due to higher emotional plasticity during this developmental stage. These findings highlight the potential of virtual reality-based mindfulness to enhance heart rate variability, supporting better physiological and emotional regulation in children. Future research should focus on the long-term effects of these interventions and their broader applicability to promote well-being and resilience in educational and therapeutic settings.

Objective: Child and adolescent depression is an increasing concern, significantly impacting their emotional, academic, and social well-being. While mindfulness-based interventions have shown effectiveness in reducing depressive symptoms, emerging technologies like virtual reality offer more engaging approaches. This study aimed to investigate the moderating effects of a virtual mindfulness programme ("Virtual EMO-Mind") in children, focusing on how neuroticism, pre-existing mindfulness skills, and demographic factors influence changes in depressive symptoms and mindfulness skills. Method: Participants were 432 students aged between 9 and 12 years ( M _age = 10.63; SD _age = 0.71; 53.6% girls and 46.4% boys). Paired-sample t -tests were conducted to assess changes in depression and mindfulness before and after the intervention. Additionally, ANCOVA and linear regression were employed to analyse the moderating effects of neuroticism, baseline mindfulness, and demographic factors on these changes. Results: The results showed that neuroticism significantly moderated negative dimensions of depression, but this effect was no longer significant after controlling for initial symptom levels. Higher neuroticism was associated with less improvement in Pleasure and reduced gains in mindfulness skills. Baseline mindfulness levels did not predict changes in depression, although participants with lower initial mindfulness skills experienced greater improvements. Gender and age did not moderate outcomes. Conclusions: This study found no significant moderating effect of neuroticism on depressive symptoms in children, contrary to findings in adult populations. Future studies should consider longer interventions, tailored assessments for children, and a broader age range to gain a more comprehensive understanding of the moderating effects of neuroticism and other factors in mindfulness-based interventions. Preregistration: This study is not preregistered.