A special region in the center of our brain acts as our master biological clock. Light sensitive cells in our retinas feed signals deep into that brain region, training neurons to sync up with Earth’s 24 hour cycle of day and night.

　　在我们的大脑中有一个精准的、像是生物时钟一样的特别区域，视网膜上的光敏细胞会将信号送至这个区域，让神经元能和地球上24小时的日夜循环同步。