Given our new understanding of the role of REM, if modern lifestyles really are reducing our dream time, we could be sleepwalking into a load of trouble. Yet despite the mounting evidence, there remains disagreement over what exactly REM sleep does.
思考题：
There is still no consensus on the role of REM sleep.
第一句：
Given our new understanding of the role of REM, if modern lifestyles really are reducing our dream time, we could be sleepwalking into a load of trouble.
1.given：（还记得吗？）鉴于，根据，因为
2. REM 快速动眼睡眠
3.sleepwalk :本意是梦游，
这里sleepwalking into a load of trouble比喻惹上麻烦；
主干识别：
we could be sleepwalking into a load of trouble
切分：
状语一：
Given our new understanding of the role of REM,
状语二：
if modern lifestyles really are reducing our dream time,
参考译文：基于我们对快速眼动睡眠的新认识，如果现代生活方式真的在减少我们做梦的时间，我们可能正梦呓着走向一堆麻烦。
第二句：
Yet despite the mounting evidence, there remains disagreement over what exactly REM sleep does.
主干识别：
there remains disagreement
切分成分：
1.Yet despite the mounting evidence，状语
Mounting evidence=growing evidence( 越来越多的证据)
2. over what exactly REM sleep does.
Over:关于；REM sleep does exactly what（快速眼动睡眠的确切作用）
What exactly sugar does in our growth (在我们的生长过程中糖的确切作用)
Yet：但是
参考译文：但虽然证据越来越多，关于快速眼动睡眠的确切作用仍存在分歧。
所以：
思考题：
There is still no consensus on the role of REM sleep.
这个说法是正确的。
