In opening statements Tuesday, a prosecutor said Melvin Morse exercised total control over the girl including "her right to draw breath."
But defense attorneys say the alleged waterboarding actually involved hair washing that the then 11-year-old girl did not like. They also told jurors that the girl and her mother, who is cooperating with prosecutors, gave authorities several conflicting stories.
Sixty-year-old Morse was arrested in 2012 and has pleaded not guilty to child endangerment and assault charges. Morse, who has authored several books and articles on paranormal science and near-death experiences involving children, denies police claims that he may have been experimenting on the girl.