The frontal lobe in the human skull is the brain tissue responsible for important functions such as memory, emotion, thinking, and spirituality. If one side of the frontal lobe is removed in surgery, the contralateral frontal lobe may compensate for the functions, and patients usually do not have obvious symptoms mentioned above. If the frontal lobe is removed bilaterally, these functions will be lost and the patient will have severe mental abnormalities, memory loss, and slow thinking response. Patients will show mania, confusion, babbling, and severe memory loss, and they will not recognize familiar people, swear, and even have aggressive behavior, and may need anti-psychotic drugs for treatment.