crack one's brains

apply establish fixate focus intensify put settle

attend center contemplate examine hammer meditate muse need peruse ponder rivet ruminate scrutinize set study sweat weigh

be engrossed in bring to bear brood over consider closely direct attention fix attention focus attention get on the beam give attention hammer away at head trip knuckle down occupy thoughts pour it on put mind to rack one's brains think hard

confuse unsettle

disregard forget ignore neglect

disperse scatter