|Portrayed by||Helen Wassell (in the tape in Depraved Heart)|
|Age||46 at death|
|Family|| Cal Lightman (son)
Emily Lightman (granddaughter)
|First Seen||Depraved Heart (tape)|
|Last Seen||Funhouse (hallucination)|
- Eli Loker: "Her name was Louise Mason. She was a patient of one of Lightman's professors when he was in grad school. She had been in the psych ward about a month when that was recorded. She told the professor she was fine. No-one could see she was actually in agony. Lightman finally got the idea to slow down the film and that's when he saw the agony in her face. That's what led him to discover micro-expressions in the first place. "
- Ria Torres: "I hope they didn't let that woman off the psych ward."
- Eli Loker: "She got a pass home for the weekend and killed herself. "
- — Loker and Torres in Depraved Heart
Not much is known about Louise's life. However, we know that when Cal was a child, Louise was in a mental hospital for an unknown disorder.
After convincing Doctors of the hospital that she was well enough for a weekend pass to see her children and husband, she commited suicide. We also know that her husband was an alcoholic.
In Lie to MeEdit
Louise, while never formally appearing on the show, is mentioned several times and is a core part of her son's storyline. She first "appears" in the episode Depraved Heart, as Cal is watching the tape of her made just before her suicide.
After this, she is mentioned at several points in the series, finally culminating in the episode Funhouse, where Cal hallucinates her and her husband.