section_path: Effects
section_name: Effects
paragraph_text: Effects
  
  Research on the processes and effects of meditation is a subfield of neurological research. Modern scientific techniques, such as functional magnetic resonance imaging and electroencephalography, were used to observe neurological responses during meditation. Concerns have been raised on the quality of meditation research, including the particular characteristics of individuals who tend to participate.
  
  Meditation lowers heart rate, oxygen consumption, breathing frequency, stress hormones, lactate levels, and sympathetic nervous system activity (associated with the fight-or-flight response), along with a modest decline in blood pressure. However, those who have meditated for two or three years were found to already have low blood pressure. During meditation, the oxygen consumption decrease averages 10 to 20 percent over the first three minutes. During sleep for example, oxygen consumption decreases around 8 percent over four or five hours. For meditators who have practiced for years, breath rate can drop to three or four breaths per minute and "brain waves slow from the usual beta (seen in waking activity) or alpha (seen in normal relaxation) to much slower delta and theta waves ".
  
  Studies demonstrate that meditation has a moderate effect to reduce pain. There is insufficient evidence for any effect of meditation on positive mood, attention, eating habits, sleep, or body weight.
  
  Luberto er all (2017), in a systematic review and meta-analysis of the effects of meditation on empathy, compassion, and prosocial behaviors, found that meditation practices had small to medium effects on self-reported and observable outcomes, concluding that such practices can "improve positive prosocial emotions and behaviors". However, a meta-review published on Scientific Reports showed that the evidence is very weak and "that the effects of meditation on compassion were only significant when compared to passive control groups suggests that other forms of active interventions (like watching a nature video) might produce similar outcomes to meditation".