[ 고1 ]_11월 (2020)__[ 38번 ]

Anne 숑 · [고1] 2020 11월 [ 38번 ]

 

Daylight isn’t the only signal that the brain can use for the purpose of biological clock resetting, though it is the principal and preferential signal, when present.  
So long as they are reliably repeating, the brain can also use other external cues, such as food, exercise, and even regularly timed social interaction.
All of these events have the ability to reset the biological clock, allowing it to strike a precise twenty-four-hour note.  It is the reason that individuals with certain forms of blindness do not entirely  lose their circadian rhythm. 
Despite not receiving light cues due to their blindness, other phenomena act as their resetting triggers. 
Any signal that the brain uses for the purpose of clock resetting is termed a zeitgeber, from the German “time giver” or “synchronizer.” 
  Thus, while light is the most reliable and thus the primary zeitgeber, there are many factors that can be used in addition to, or in the absence of, daylight.