chunk: Mark reveals to Helen through home movies taken by his father that, as a child, he was used as a guinea pig for his father's psychological experiments on fear and the nervous system. Mark's father would study his son's reaction to various stimuli, such as lizards he put on his bed and would film the boy in all sorts of situations, even going as far as recording his son's reactions as he sat with his mother on her deathbed. He kept his son under constant watch and even wired all the rooms so that he could spy on him. Mark's father's studies enhanced his reputation as a renowned psychologist.