Dr. Christine Blasey Ford’s allegation that Judge Brett Kavanaugh sexually assaulted her more than 30 years ago has raised questions about the longevity and accuracy of memory. These questions have only grown after two more women came forward with their own accusations against the Supreme Court candidate, all dating back decades. Although science may not be able to test the veracity of these claims, it can provide important insights into memories of trauma and test the characteristics of reported memories against decades of research on emotional memory formation.
Many in the public are aware that memory is prone to error and that our memories are not like tape-recorded replays of our prior experiences. When encoding an event, we focus more attention on aspects that our brain appraises as important and less on those deemed insignificant. This is what we memory scientists refer to as central vs. peripheral details. Moreover, as time passes, we can actually lose memories, forget details of those we do retain and update or modify aspects of others through repeated retrievals.
Such flaws of memory are features, not bugs. They are ways that our brain-based memory systems have been sculpted to function adaptively. Memories of trauma are like normal memories in these respects, but they have important characteristics that make them much different from normal, everyday memories.
Memories of trauma are intense and often stand out to the person who has them. After being traumatized, we remember the event for a long time — likely forever. There’s a reason for this: The way our body responds to stress is meant to promote long-term survival. Thus, when we encounter a stressful situation, chemicals such as cortisol and norepinephrine are released to focus our attention on the stress-related information and store it in a very powerful way. The brain is basically saying, “This is important; remember it because it could later save your life.”
This is not to say that memories of trauma are immune to imperfections. Indeed, memories of trauma are sometimes not recalled immediately after the event, and like normal memories, there are components that may be stored ineffectively (e.g., fragmented, lacking time-sequence information) for later organized recall and parts that may be altered over time. However, it is rare for traumatized individuals to completely forget the event itself. Thus, it is not surprising that Dr. Ford, for example, remembers that her alleged sexual assault occurred, even if it happened more than 30 years ago. This is consistent with existing scientific evidence regarding the nature of memories for trauma.
Extensive research has also shown that stress and trauma narrow our attention, exaggerating our focus on the most important aspects of an event. This allows us to remember the central components of the threat. An example of this narrowing of attention is known as weapon focus. If an individual is held at gunpoint, he or she is likely to focus on the gun (which makes it a central detail) and remember it much better than the color of the assailant’s shirt (less-important peripheral detail), for instance. This is an adaptive response meant to help us survive a traumatizing experience.
In Ford’s recollection of the alleged sexual assault, she vividly described some of what, for her, were central details of the experience. Those include being pushed into a bedroom, being held down by a boy she knew, and the boy covering her mouth when she tried to yell for help. Some of the details that she cannot recall or at least cannot recall with certainty (e.g., whether the boys followed her upstairs, how she ended up getting home that night, where the party was held) could be considered peripheral details — that is, things she may not have noticed or given much attention to at the time. Other details may have changed over time, perhaps during rare occasions when she tried to recall what happened rather than push it out of her mind.
So while peripheral details about an emotional event can be inaccurate, the memory of the event itself — that it occurred, the gist of what happened — as well as details perceived to be central to the experience, are usually resistant to such impairment. Thus, science suggests that Ford’s memory that a sexual assault actually occurred, along with its gist and most central details, would likely remain very powerfully, perhaps even indelibly, etched into her brain.
We do know one way that memories can be altered or corrupted: outside influences. Misleading questions from authority figures can distort central details. However, no evidence is available of Ford being subjected to “suggestive” influences sufficient to distort central details of her memory. Importantly, competent therapists are not such influences.
One focus of my work is understanding how the timing of stress influences long-term memory. In studies over the past decade, I have observed that stress enhances memory for information that is presented around the time of the stress, while impairing memory for information that is presented long before or after the stress. Such findings are consistent with the adaptive nature of emotional memory, as it pays to remember things that happen around the stressor because those things could predict future threats. What happens later, after the stress has subsided, is relatively less important. Interestingly, in the available accounts of Ford’s recollection of being sexually assaulted, she recalls more details of what happened in the bedroom, while forgetting details of what happened before she was forced into it and after she escaped.
And although I have observed that genetic factors, biological sex and even hormones during different phases of the menstrual cycle can influence how stress impacts memory, I have no data suggesting that women are less reliable than men when it comes to memory. In fact, it’s the opposite: some of my work and that of other scientists suggests that the memories of females are more likely to benefit from the enhancing effects of stress and less likely to suffer from its impairing effects. Those may be important findings to keep in mind as we all attempt to evaluate Ford’s memories and credibility, not to mention those of other victims of trauma.