Meditation is associated with measurable changes in brain structure and function, including increased plasticity in the prefrontal cortex and hippocampus, improved attentional network activity, and reduced dominance of the default mode network. Physiological markers such as higher BDNF and lower inflammatory indices also show positive trends. Psychological and cognitive improvements accompany these changes. The analysis, based on eight randomized or controlled studies published between January 2018 and April 2025, found significant effects across all studied domains, though heterogeneity was high.
A systematic review of 35 empirical studies (N=36,533 subjects) found that 7.6% of the general population experienced at least one sleep paralysis episode over their lifetime, with higher rates in students (28.3%) and psychiatric patients (31.9%). Sleep paralysis is an inability to move at sleep onset or upon awakening, often accompanied by hallucinations. It can be isolated, familial, or part of narcolepsy. Prevalence estimates range from 1.7% to 40% in the general population, peaking in the thirties. Associated factors include PTSD, narcolepsy, panic attacks, sleep deprivation, fatigue, and stress.