Prechtl H F, Nijhuis J G
Behav Brain Res. 1983 Oct;10(1):119-24. doi: 10.1016/0166-4328(83)90157-2.
The human oculomotor system becomes active long before birth. At about 16 weeks (post-menstrual age) the first slow changes of eye position can be observed with the aid of real time ultrasonography. At 18-20 weeks more rapid eye movements are detectable. There is a gradual decline in the percentage of time spent in rapid and slow eye movements from 32-40 weeks. These eye movements are organized in episodes of activity, divided by episodes of quiescence which are at first unrelated to cyclical changes in other variables (such as breathing movements, body movements and fetal heart rate patterns). At about 36 weeks gestation, REM and non-REM episodes become linked with other changes and then represent behavioural states identical to those seen in the newborn infant. This organization of behavioral states in the fetus is identical with that found in preterm infants of comparable age. Opening of eyelids is difficult to see before birth but the existence of episodes of wakefulness seems most probable. Hence fetal eye movements will be in part related to wakefulness. In the newborn at term, the interval distributions of REMs during sleep and of scanning eye movements during wakefulness are statistically different.
人类动眼系统在出生前很久就开始活跃。在大约16周（月经龄）时，借助实时超声检查可以观察到眼球位置的首次缓慢变化。在18 - 20周时，可以检测到更快的眼球运动。从32 - 40周，快速和慢速眼球运动所占用时间的百分比逐渐下降。这些眼球运动以活动期的形式组织起来，中间被静止期隔开，起初这些静止期与其他变量（如呼吸运动、身体运动和胎儿心率模式）的周期性变化无关。在妊娠约36周时，快速眼动（REM）和非快速眼动发作与其他变化相关联，然后代表与新生儿所见相同的行为状态。胎儿行为状态的这种组织方式与同龄早产儿中发现的情况相同。出生前很难看到眼睑张开，但最有可能存在清醒期。因此，胎儿的眼球运动部分与清醒有关。足月新生儿睡眠期间快速眼动的间隔分布和清醒期间扫视眼球运动的间隔分布在统计学上是不同的。
