Attraction is less common than repulsion. Changing the polarity would not feel any different with a static ball.

Attractive feelings can be caused several things:
-trying to 'cheat' a little bit in building a larger PSI ball by manually moving your hands apart instead of letting the building energy push them apart
-its possible to build a void (lack of energy) between your hands
-something drawing off the energy from the middle. What you are actually feeling in this case is the (out) flow of energy not attraction per se
-someone trying to counter what you are doing (extremely rare)