1 If the speedbrakes are in armed position they are independent of autobrake or reverse thrust.
When thrust levers are retarded to idle,spin up >60kts detected or any gear strut compression will deploy the flight spoilers.
Right gear compression will deploy the ground spoilers also.
2 If the speedbrakes lever is in down position during landing or rejected take-off,the auto-speedbrakes sys is also independent of autobrakes and operates when spin-up is more than 60kts,thrust levers are retarded to idle and reverse thrust levers are positioned for reverse thrust.
If you advance any thrust levers the spoiler panels will retract.