What hormone is responsible for sleep?

During passage through the eye; light is bent:

Autokinesis can occur when flying at night and staring at a point source of light; the light will appear to move giving the pilot a false sense of motion which can be interpreted as aircraft motion.

Psychology is:

What hormone is responsible for sleep?

Control of the body’s internal circadian biological clock resides in the ____________.

Post-World War II, ________________________________________

Psychology is:

The master gland of the hormonal system is?

Research must be: