Mental Ascension Question

By Scoates, in Deathwatch Rules Questions

Mental Ascension on pg 95 of Rites of Battle, says that a marine can double a characteristic bonus, "such as doubling his perception bonus to enhance his senses."

Either I don't understand what it means, or it is worded very poorly. If my perception is 43, my perception "bonus" is 4, and has nothing to do with a standard perception roll. Does it mean that I double that stat? That seems unlikely. Can someone point me in the right direction.

The only thing I can think of are those from chapters during char gen which would make no sense at all.

Alex