Scientists say traumatic moments are in memory

In her testimony on Thursday at the confirmation hearing of Judge Brett Kavanaugh, Christine Blasey Ford alleged that Kavanaugh had sexually assaulted her at a party in 1982, when she had 15 years old and that he was 17 years old.

Kavanaugh firmly denied these allegations.

But memory is fallible. An issue that concerns many people is: how can we remember something that happened more than 35 years ago?

Quite well, say the scientists, if the memory is of a traumatic event. This is because of the key role that emotions play in creating and storing memories.

Every day, our brains store or "encode" only some of our experiences. "What we pay attention to is what is most likely to be encoded," says Jim Hopper, associate in psychology at Harvard University and consultant on sexual assault and trauma.

A region of the brain called the hippocampus plays an important role in this process. Ford referred to the hippocampus when he was questioned by Senator Dianne Feinstein, D-Calif., On how she was so sure that Kavanaugh was the author of the Presumed aggression.

"The hippocampus certainly plays a role in short-term memory, then in their transfer and consolidation into long-term memories," says Hopper.

If an event elicits an emotional reaction within us, it is more likely to happen in our memory. "Things that have a more emotional meaning tend to be more coded," he says.

And when something arouses intense negative emotion, such as trauma, it is even more likely to be encoded in the brain.

"The stress hormones, cortisol, norepinephrine, which are released during a terrifying trauma tend to make the living and memorable experience, especially the central aspect, the most significant aspects of the experience for the victim, "says Richard McNally, psychologist at Harvard University and author of the book Remember the trauma.

This is because a high stress state "alters the function of the hippocampus and places it in a super encoding mode," says Hopper, especially at the beginning of a event. And "the central details [of the event] burn in their memory and they can never forget them. "

Whether it is sexual assault victims or soldiers in combat or survivors of an earthquake, people who have experienced traumatic events tend to remember the elements the most essential and scary events for life.

However, this does not mean that these memories include all the details of the event. The brain keeps the most important things at the expense of peripheral details.

Take, for example, an employee of a convenience store who is being robbed of firearms, says McNally. "The person can often encode the characteristics of the weapon, the weapon shows him the face, but does not remember whether or not he wore glasses, because his attention is focused on the most central aspects of the experience. "

McNally says that this would explain why Ford remembers what happened during the alleged assault, but she does not remember the date of the party or its location.

"They have been forgotten because they have never been encoded," says McNally. "When someone has an experience like this, he does not necessarily say," I'd better shut up. "They're concerned about trying to escape this terrifying experience."

In addition, "people in general are not good with regard to dating events, whether it is traumatic events or non-traumatic events," he adds. -he. Unless there are other clues about the date, most people tend to forget when something has happened.

As for the memory of the perpetrators of sexual assault, there has been little research on this, says Hopper. But what research on emotions and memory suggests, is that the author's memory will depend on his emotional state, he says.

"If keeping someone and trying to undress was an entertaining experience, or a routine, familiar experience, you're less likely to store it," he says. "It really depends on how the author is related to things."

Another factor that affects how memories are stored is the consumption of alcohol.

"In general, alcohol can make you forget things," says Mary Beth Miller, clinical psychologist at the University of Missouri, Columbia, who has studied the impact of alcohol consumption on the creation and recovery of alcohol. memories.

Earlier this month, Ford said The Washington Post that she remembers that Kavanaugh was "drunk" while she remembers taking a beer that night.

Other accusers who did not testify on Thursday also suggested that Kavanaugh was one of a group of friends who abused alcohol in the 1980s.

In his testimony, Kavanaugh said that he loves beer, but he denied ever drinking as much as he did not remember things.

Miller says that memory loss due to alcohol – power outages – is very common among young people.

"In a power outage, you walk around, you talk to people," says Miller. "And a lot of times in a power outage will be very consistent.You are just doing your thing, and people do not know, because it's hard to know if anyone is in a down state of current."

These power outages are what scientists call "fragmentary" failures, where a person has a partial memory loss, but "you can usually remember if someone reminds you later."

These fragmentary power cuts can occur at low concentrations of alcohol in the blood, as low as 0.06, she says. (For comparison, the legal limit of conduct is 0.08 in all states except Utah.)

Miller also says that animal studies suggest that "the adolescent brain is actually more sensitive to the effects of alcohol on memory."

A permanent memory disorder, what scientists call a "total breakdown," has a beginning and an end. She says these effects usually occur at higher blood alcohol concentrations, around 0.24.

This is because higher amounts of alcohol prevent short-term memory from being converted into long-term memory, Miller says.

"And people with a history of abusive alcohol consumption are more likely to have more memory deficits," she adds.