How to use FULLTEXT in mysql innoDB? Sorry, if my question is naive, but it has puzzled me, and cannot benchmark the performance.

I want to use the newly introduced feature of innoDB for FULLTEXT index. I wonder what is the difference of 

FULLTEXT(title,body)


and

FULLTEXT(title),
FULLTEXT(body


Is there any effect on the search performance and the ranking of results.
For InnoDB,

FULLTEXT(title,body) -- useful only for MATCH(title, body) AGAINST ...

FULLTEXT(title) -- useful only for MATCH(title) AGAINST ...


So, if you are doing both types of MATCH, you need both indexes.