I accidentally turned on splatter mode and can't turn it off

I'm guessing this is the correct answer. I kept futzing until suddenly it worked again. The last thing I did was select a different brush, tho I'd been doing that over and over and over again. The layer itself was "normal" and the the brush mode pull down menu was "normal", but instead of the soft brush having decreasing opacity across its width, instead it was using decreasing probability of applying on pixels across its width. The result was that ugly  spattering. I think it must have been one of the 5 "soft round" brushes that had some strange attribute. Since their names are indistinguishable, I'll have to explore them in minute detail to try to understand why they're different. Thank you.