Intensive mindfulness practice attenuates habituation of the acoustic startle reflex, meaning experienced meditators continue to respond strongly to repeated startling sounds rather than tuning them out. Moderate practice, however, enhances habituation, suggesting a non-linear effect of practice intensity. The study measured eye-blink muscle responses to 36 loud noises in three groups: meditation-naïve, moderate practice, and intensive practice. Only the intensive practice group showed reduced habituation across the entire experiment. Greater practice intensity correlated with slower habituation in the intensive group. The effect is modest and provides tentative evidence that intensive mindfulness may alter automatic sensory processing.
Patients with idiopathic REM Sleep Behavior Disorder (iRBD) and those with Non-Rapid Eye Movement Parasomnia (NREMP) differ not only in the content of their morning dream recalls but also in the structural organization of those recalls. iRBD patients were more likely to recall dreams and had more white dreams (feeling of having dreamt without memory). Speech graph analysis revealed that iRBD dream reports had stable, linear sequential structures, while NREMP dream reports were more recursive and less stable, with higher graph connectivity scores. These findings suggest distinct underlying mechanisms for dream recall in these two sleep disorders.
Startle modulation, specifically habituation and prepulse inhibition (PPI), reflects early sensory processing in the brain. In a comparison of regular meditators (32 individuals) and meditation-naïve individuals (36 individuals), no significant group differences emerged in either habituation or PPI. However, among meditators, those who reported being able to sustain non-dual awareness during practice (18 individuals) showed significantly greater PPI than those who could not (14 individuals). These results suggest that subjective differences in meditation experience may relate to distinct sensory processing characteristics.