Jessica is describing her new career to a friend. Because she records many aspects of a subject's sleeping habits, she is called a (n) ___.

Answer: Polysomnographer

Explanation:

Polysomnographer is the person who follows the field of polysomnography. The person tends to study sleep disorder, habits and patterns. It is done by researching and observing heart rate, breathing status, brain signals, movement of hands, legs or eyes etc.

According to the question, Jessica is pursuing her new career as polysomnographer because she is involved in recording and noticing sleeping habits and pattern of people in her work field.