 [ Symptoms ] can i self administer systematic desensitization to treat a phobia or does it have to be under the care of a therapist [ Disease ] adult brain tumors are diseases in which cancer malignant cells begin to grow in the tissues of the brain the brain controls memory and learning senses hearing sight smell taste and touch and emotion it also controls other parts of the body including muscles organs and blood vessels tumors that start in the brain are called primary brain tumors