first third of your sleep pattern.翻译

翻译成睡眠模式的前三分之一 研究表明深睡状态只发生在这个时段
Sleep begins in stage one of the sleep phase known as NREM, or non-rapid eye movement, sleep. NREM sleep has four stages: light sleep, deeper sleep, and two stages of deepest sleep.and two stages of deepest sleep. Stage one is the "drifting off" period of light sleep in the transition between wakefulness and sleep and comprises about 5 percent of the entire sleep period. Stage two sleep involves a change in brain-wave patterns and increased resistance to arousal and accounts for 45–55 percent of total sleep time. Stages three and four are the deepest levels of sleep and occur only in the first third of the sleep period. NREM stage four sleep usually takes up 12 to 15 percent of total sleep time. Sleep terrors, sleep walking, and bedwetting episodes generally occur within stage four sleep or during partial arousals from this sleep stage.

你的睡眠时段的前三分之一

注：因为没有上下文，所以也可以理解为：某一类睡眠方式（含三个时段）的第一阶段（也就是作者在这之前可能已经提及这类睡眠方式）。

睡眠模