I have splits all over my tongue. They don't hurt and they aren't really noticable unless I stick my tongue out. As a kid I always suffered from being very sensitive to strong flavours, mints, aniseed, vinegar, salty things, chilli, curry, etc would make my tongue really tingle.
I went to the doctor one day after eating some mustard (well I was only six or seven and kids do that sort of thing LOL) that made my tongue swell up. He told me that I have a condition known as 'exaggerated tongue' which means it is about ten times more sensitive than normal. Told me as long as I keep away from really strong flavours I'll be fine. Anyway, when I got to about 18 or 19 I started to notice that things that weren't absolutely fresh, like milk a couple of days old, or fish that wasn't really fresh, tasted a bit odd. The doc sent me to a specialist who told me that I wasn't unique (about 1 in 10,000 people suffer from some level of this) and he suggested that it was a benefit as I wouldn't ever get food poisoning as I'd be able to taste anything that was even the slightest bit 'off'. I have just had to learn to live with it, stick to milder flavours and avoid anything that I know for sure sets it off tingling.
Don't worry, if it doesn't hurt and the dots are always there it'll be part of this condition.