20. A patient having an electroencephalogram is having a recording made of the electrical activity in their:

• Brain
• Heart
O Muscles
O Skin

• Brain

A patient having an electroencephalogram (EEG) is having a recording made of the electrical activity in their brain. The purpose of an EEG is to measure and analyze the electrical signals produced by the neurons in the brain. It helps in diagnosing various neurological conditions and monitoring brain activity during different tasks or states, such as sleep.