Thumbs up/Down

[user-removed]

Just starting with Spotify and I have some questions about thumbs. Do they affect the station only or the entire service?  I gather that one cannot change a thumbs up/down and that is a sore point.

My main,question is thumb upped songs in radio stations that I never did and almost never like.  Has anybody else seen this and what can be done about it?  They are usually from artist s I have never played.  What gives?  Thanks.