Meditation acutely improves psychomotor vigilance, and may decrease sleep need.2010
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Медитация резко улучшает психомоторную бдительность и может уменьшить потребность во сне.
Сгенерированная сводка:
Вопрос о том, действительно ли медитация может заменить часть сна или погасить недосып, находится в стадии дальнейшего изучения.
В экспериментах с опытными медитаторами длительность сна измерялась с использованием журналов сна и актиграфии.
У этих субъектов было достаточно времени для ежедневной медитации, так что это могло бы вызвать заметное уменьшение общего времени сна, если медитация действительно может заменить часть сна или компенсировать его каким-либо другим способом.
В качестве первого шага к ответу на этот вопрос мы использовали журналы актиграфии [,], ЭЭГ и сна для оценки времени сна, бодрствования и медитации, и обнаружили, что у этих субъектов в целом более короткое время сна по сравнению с контрольными субъектами, а также сравнили опубликованным нормам [,].
Подгруппа медитирующих также прошла множественные тесты на задержку сна, чтобы выявить дневную сонливость, и не выявила никаких признаков недосыпания.
Abstract:
Conclusion
These results suggest that meditation provides at least a short-term performance improvement even in novice meditators. In long term meditators, multiple hours spent in meditation are associated with a significant decrease in total sleep time when compared with age and sex matched controls who did not meditate. Whether meditation can actually replace a portion of sleep or pay-off sleep debt is under further investigation.,Meditation appears to provide at least a short term improvement in reaction time performance, and may also provide a longer term reduction in sleep need roughly equal to the time spent in meditation.
Result
Novice meditators were tested on the PVT before each activity, 10 minutes after each activity and one hour later. All ten novice meditators improved their PVT reaction times immediately following periods of meditation, and all but one got worse immediately following naps. Sleep deprivation produced a slower baseline reaction time (RT) on the PVT that still improved significantly following a period of meditation. In experiments with long-term experienced meditators, sleep duration was measured using both sleep journals and actigraphy. Sleep duration in these subjects was lower than control non-meditators and general population norms, with no apparent decrements in PVT scores.,In the first study, we asked whether meditation might impact PVT performance, relative to pre-test conditions and our other treatment groups. In this initial group, we trained 10 students in simple breathing-focused meditation, and asked them to meditate for 40 minutes. PVT performance was assessed just prior to the meditation period, 10 minutes following meditation, and again one hour later. Each subject was tested on two different days with meditation treatment (M), two days with a 40 minute nap (N), and two days with 40 minutes of relaxed eyes-open activity (C). The six days of testing on each subject were spaced over multiple weeks, and each day's activity randomly assigned, unknown to the subject in advance. Later, we examined whether meditation improves PVT performance after 32 hours of sleep deprivation for the same set of subjects, which was done once for each subject.,Our response variable was change in PVT reaction time (pre-treatment - post-treatment). Because we found no effect of Day in our C, N and M treatments (Day: ,), we averaged the two treatment days for our pre- and post-treatment reaction times for the C, N and M treatments, and used the single day of data following sleep deprivation (four treatments in total).,In all 10 subjects, performance on the PVT improved (faster reaction times) following meditation (,, Figures , and ,, Table ,). See the methods section for a more detailed statistical analysis. The direction and amplitude of this trend was congruent for 9 out of the 10 subjects on each of the two days. One hour later, many subjects return to baseline performance with no significant differences relative to control days (data not shown).,In contrast to meditation, the reaction times slowed for 9 out of 10 subjects following a nap (,, Figures , and ,, Table ,). This trend was congruent on both nap days for 9 out of 10 subjects. The slower times following a nap were probably due to sleep inertia as shown previously[,]. One hour later, reaction times improved, but were still below baseline (data not shown), again consistent with some other studies on the dissipation of sleep inertia[,]. Surprisingly, even the control activities showed a clear slowing on the PVT (,; Figure ,), perhaps due to a mild circadian decline in performance during the late afternoon (the "mid-afternoon dip"). As is common in college students, our subjects had relatively late bed-times (median of 1:00 am) and wake-times (median 8:30 am) and thus our 4:00 pm post-treatment time may have coincided with their nadir in performance. In light of the results following naps and control activities, the improvement post-meditation appears even greater, since the improvement occurs against the normal decline.,To determine if this post-meditative effect could improve performance under conditions of a large sleep debt, we next challenged each subject with a full night of sleep deprivation. As expected, after approximately 32 hours with no sleep, the subjects had slower baseline PVT measurements (289 ms versus 255 ms; ,), and against this lower baseline, the enhancement with meditation was again significant (,, Figures , and ,, Table ,). In contrast to the initial testing when subjects were well rested, we observed a number of lapses being committed by subjects in this experiment, which were extremely rare in the other treatments. A lapse was defined as an RT of >500 ms or an erroneous response. The number of lapses post-meditation declined both for individuals and as a group (,), further supporting a global improvement in cognitive and psychomotor alerting responses following meditation.,This experiment suggests that meditation serves a performance-enhancing and perhaps restorative role even in novice meditators. To address this possible restorative role over longer durations, we conducted an initial study on seven long-term "expert" meditators in India, who typically spent 2-3 hrs/day in meditation, versus 23 age- and sex-matched non-meditators as controls. These subjects had sufficient amounts of daily meditation time such that it might produce a noticeable decrease in total sleep time if meditation can actually replace a portion of sleep, or compensate in some other way. As a first step to address this question, we used actigraphy[,], EEG, and sleep journals to assess sleep, wake, and meditation times, and found a generally shorter sleep time in these subjects (Table ,, Figure ,) relative to our control subjects (5.2 versus 7.8 hours per day; ,), and also compared to published norms[,]. In addition, there was no evidence of sleepiness on the PVT when it was run multiple times in a subset of these subjects compared to subjects with more typical sleep times (7-8 hours/night) (data not shown). A subset of meditators also underwent Multiple Sleep Latency Tests, to look for day-time sleepiness, and did not display any evidence of sleep debt (mean sleep latency being 18.25 minutes, above population norms). Some subjects were also monitored by EEG, video, and/or direct observation during bouts of meditation to confirm that very little (if any) sleep occurred during the meditation bouts. EEG showed very little sleep of any stage, and video and direct observations showed no signs of head droop or other postural changes indicative of sleep.,Daily sleep and meditation amounts in meditators vs. controls,. Meditators had significantly shorter sleep durations than non-meditators (5.2 versus 7.8 hours per day; ,). Error bars denote one standard error.