Solar radiation that is visible at the earths surface is

Visible light

Explanation:

The part of solar radiation that is visible at the earth's surface is called the visible light.

Human eyes is sensitive and able to detect electromagnetic radiation within this range.

dopamine..

"it was found that some people who were taking the drug l-dopa to raise their levels of dopamine were developing schizophrenic-like symptoms supporting research a strength of the dopamine hypothesis is that there are many studies which have shown support for the neurochemical explanation."