noun
one's mind; in one's head
Refers to the mind as the place where memories, images, or thoughts reside; often used in phrases like 脳裏に浮かぶ (come to mind) or 脳裏をよぎる (flash through one's mind).
その光景が今も脳裏に焼き付いている。
That scene is still burned into my mind.
ふと、昔の友人の顔が脳裏に浮かんだ。
Suddenly, the face of an old friend came to mind.
Compound of 脳 (brain) and 裏 (back, inside), literally 'the back of the brain' or 'inside the brain', used figuratively for the mind's eye or mental space.