Pokémon Black Version and Pokémon White Version - Attack stat, Defense stat, and so on
Effects that refer to a Pokémon’s Attack stat, Defense stat, Speed stat, Special Attack stat, or Special Defense stat refer to the original stat, unmodified by stat stages or by the effects of moves, Abilities, items, and so on (other than by effects that directly modify those values during battle, such as Power Split, Power Trick, and Transform). A Pokémon’s Attack stat and so on will revert to their original values when it leaves the battle or when the battle ends.
However, effects that refer to a Pokémon’s current Attack, current Speed, and so on, refer to such stats modified by effects, such as those listed above, and by stat stages. Examples of such effects include Gyro Ball and Electro Ball.