Quick question: DJ hero 2 notes on hard mode

So, I've switched to hard and i noticed that in some tracks there are those single square notes with a big down arrow in the center and I dont know what i'm supposed to do. I looked up on the manual and I only found something about "crossfade spikes" but I dunno if it's them , it says to quickly move the crossfader in that direction but the arrow is down so...

Any help ?

Woops it's not pointing down, it's pointing up, it looks like this |>|turned 90 degrees on the left , but I still dont know what the hell I'm supposed to do

reedit: ok , so the arrow it pointing up and down, so i tried to press the button and quickly move the plate in that direction and it worked a few times but I'm not 100% sure , am i doing it right ?