‘Indelible in the Hippocampus Is the Laughter.’ The Science Behind Christine Blasey Ford’s Testimony

5 minute read

Christine Blasey Ford drew heavily on her psychology background while giving an emotional testimony about her alleged sexual assault by Supreme Court nominee Brett Kavanaugh, discussing everything from brain chemistry to risk factors for anxiety.

Ford, a professor of psychology at Stanford University and Palo Alto University, used her scientific expertise to answer questions from Sen. Dianne Feinstein and others about her allegations that Kavanaugh pushed her onto a bed, covered her mouth and attempted to remove her clothes, with intent to rape her, during a Maryland high school party in the 1980s. Ford also said a second person, Mark Judge, was in the room at the time, and may have helped push her onto the bed.

Kavanaugh has denied Ford’s claims, as well as sexual misconduct accusations brought by two other women.

When Sen. Feinstein asked, “How are you so sure that it was he?”, Ford said she could be sure of Kavanaugh’s identity in “the same way I’m sure I’m talking to you right now,” before launching into an explanation of brain chemistry. The neurotransmitter epinephrine, Ford explained, “codes memories into the hippocampus, and so the trauma-related experience is locked there, whereas other details kind of drift,” she said.

Experts say that during trauma, the brain does select for salient details. Research indeed shows that norepinephrine, a neurotransmitter released in response to stress or emotional arousal, allows the brain to zero in on certain things and tune out others, says Charan Ranganath, director of the Memory and Plasticity Program at the University of California at Davis. (Ranganath is not involved in the Kavanaugh confirmation process.) “People tend to think of memory as all-or-none — as if you either remember everything, or your entire memory is flawed,” Ranganath says. “Neuromodulators like norepinephrine can change what will and will not be prioritized, so it’s very possible that some aspects of an event can be retained and recalled fairly accurately for long periods of time, while other, less significant details may be lost.”

You can think of it like turning up the contrast on your TV, Ranganath says. “If the contrast is low, you can see everything, even though some things are brighter than others,” he says. “But if you crank up the contrast, what you’ll find is that some things are super bright, and everything else is kind of hard to see.”

As a result, the brain tends to make “the things that are most salient stand out,” which allows it to store those details clearly, even as others fall out of focus or fade over time.

Ranganath also compares the phenomenon to seeing a movie and later relating the plot to a friend: You’d likely think to tell them about the most dramatic scene, but “not the color of the carpeting or the leather couch” in the room where the scene takes place.

In Ford’s testimony, she said she was positive that Kavanaugh was the person who assaulted her, but said she could not remember details like the exact date of the party or how she got home afterward.

When asked by Sen. Patrick Leahy about her strongest memory from that night, for example, Ford responded that, “Indelible in the hippocampus is the laughter, the uproarious laughter between the two [men], and their having fun at my expense.” (The hippocampus is a part of the brain involved in storing memory.)

“The way we remember things is that we make narratives out of them,” Ranganath explains. “The fact that someone was laughing during this traumatic event would be something that really sticks out.”

Kavanaugh has not only denied that he assaulted Ford, but also that he was at the party that night. Ford has also said that Kavanaugh was visibly drunk at the party; he has denied ever drinking heavily as a young man.

Regardless of the particulars of this case, Ranganath says it’s indisputable that alcohol messes with memory.

“Alcohol changes what you pay attention to. Alcohol does affect your retention of this information,” he says. “These mental states can play a huge role in what you can remember … and make it harder to remember these events in detail.”

Ford also discussed other psychological principles during the course of her questioning, including her experience with anxiety and post-traumatic stress disorder, which at points in her testimony she referred to by the scientific term sequelae, or after-effects of trauma. Prompted by questioning from prosecutor Rachel Mitchell, Ford discussed how the alleged incident may have contributed to those conditions.

“The etiology of anxiety and PTSD is multifactorial. [The incident] was certainly a critical risk factor. That would be a predictor of the [conditions] that I now have,” Ford said. “I can’t rule out that I would have some biological predisposition to be an anxious-type person.”

Later, Ford added that traumatic experiences that occur early in life can be more damaging psychologically than those that occur later in life, since the brain is still developing. This phenomenon has been documented extensively in scientific literature.

Ford also said she was able to escape the alleged assault due to fight or flight, the stress response and survival mechanism that allows humans to deal with threatening situations. Research suggests that fight or flight can be triggered by a range of stressors, from those that are truly life-threatening — as Ford has said she feared her alleged assault was — to those that are more minor.

“I was definitely experiencing the fight-or-flight mood,” Ford said. “I was definitely experiencing the surge of cortisol, and adrenaline and epinephrine” consistent with that response.

More Must-Reads from TIME

Write to Jamie Ducharme at jamie.ducharme@time.com