Could you explain what is an mri or eeg like exactly?

Structure/function: An MRI looks at the structure of the body by using magnetic fields. You lie quietly on a table inside a donut-shaped magnet. Sometimes IV contrast is used to bring out the detail in certain structures. An eeg looks at brain function. Wires are placed on the scalp using an adhesive paste, and you lie quietly while an machine records the electrical signals generated by brain activity.