There are two groups that have used the name Negative Reaction. One is an Australian experimental group that made music in the early 80s. The other is a sludge/doom metal band from New York, USA. The sludge/doom metal group's biography:
Ken-E Bones - Vocals, Guitars (Orange 120 OD Feedback), Native American Flute
The Neil - Drums
Capt'n Manny - Bass Negative Reaction is a part of the Sludge/Doom metal scene. NR uses feedback as a hammer and the guitars tuned to A as the stake.

Read more about Negative Reaction on Last.fm.