The name of one region of the spectrum that has a wavelength longer than waves of the visible light region

Infrared

Explanation:

The region in the electromagnetic spectrum that is inmediatly after the visible light (the light human eyes are able to see, betwen 400 nm and 800 nm) is the infrared region (between 800 nm and 1 mm).

It is important to note this type of radiation is not visible to the human eye, and is divided in the following sub-regions:

- Near infrared or long wave infrared

- Medium or medium wave infrared

- Far infrared or short wave infrared

i believe it is capitalists.  

a. theta waves. this is because the person is in a light sleep which means the brain waves would show these kind of waves.