Prior to the invention of the ________, scientists believed that sleep was a single state.
A) PET scan
B) EEG
C) MRI
D) EKG

Question

Quizplus · Accepted Answer

EEG (Electroencephalogram) is a device that measures brain waves, and it was with the invention of the EEG that scientists were able to differentiate between different stages of sleep. Prior to this, they believed sleep to be a singular state. PET scans, MRIs, and EKGs do not measure brain waves and are not directly related to the study of sleep.

Prior to the Invention of the ________, Scientists Believed That