Exploring psychological and neurophysiological effects of a mindfulness-based intervention in healthy young adults.

Mindfulness-based interventions improve psychological well-being but their effects on neurophysiological measures remain inconsistent. Traditional group-averaging approaches may overlook inter-individual variability, leaving doubts about if and how MBIs can influence one’s well-being. This study investigates the effect of Integral Meditation (IM) on behavioural and neurophysiological outcomes in young adults.Fifty participants were randomized to intervention (n=22) or inactive control group (n=28). Behavioural outcomes included dispositional mindfulness, state and trait anxiety, interoceptive sensibility and interoceptive accuracy. Neurophysiological outcomes included individual alpha peak (IAP) frequency, IAP power and alpha relative power from resting-state EEG. Main effect linear models evaluated pre-post group differences, while interaction models examined whether intervention effects depended on baseline measurement. P-values were adjusted using Benjamini-Hochberg with FDR=0.10.IM significantly improved dispositional mindfulness (Beta=7.01[0.97;13.04],adjusted p-value=0.09) and interoceptive sensibility (Beta=0.41[0.19;0.63],adjusted p-value=0.005) and their sub-components. No effects were observed for anxiety and interoceptive accuracy. Although no main intervention effect emerged for neurophysiological indices, IM increased IAP power in participants with lower baseline IAP levels (Beta=-0.40[-0.73;-0.07],adjusted p-value=0.06), particularly in the left-lateralized electrode cluster (Beta=-0.49[-0.81;-0.17],adjusted p-value=0.03). Results suggest that IM promotes psychological improvement, enhancing mindfulness and interoceptive sensibility, and baseline-dependent modulation of brain alpha activity, highlighting the importance of individual variability in mindfulness research.