Our Fallible Memories in the Courtroom: Q&A with Daniel Schacter

“…cognitive neuroscience research could help jurors and other participants in the legal system to better understand why it is that memory does not operate like a video recorder, and why it is sometimes prone to error and distortion.”

Neuroscience is in the legal spotlight more than ever before, with the courts increasingly considering science-based evidence – such as neuroimaging techniques to detecting lies or to confirm memories. But while researchers have had success in using neuroimaging to test memories in the lab, it is premature to consider such techniques in the courtroom, say many cognitive neuroscientists.

Writing in the February Nature Neuroscience, Daniel Schacter of Harvard and Elizabeth Loftus of the University of California, Irvine, say there are still some ways in which the courts can use neuroscience – but in an educational role rather than as data for evidence.

In a recent case before the New Jersey Supreme Court, the defendant – a murder suspect – challenged eyewitness testimony due to possible influences on the eyewitness’ recollection. In its ruling, the Court changed the legal standard for eyewitness testimony, requiring that any issues related to suggestive influence on the witness be brought to bear before considering the related testimony.

As a result of this ruling, in July 2012, New Jersey developed new guidelines for jurors, instructing them “that memory is not foolproof. Research has shown that human memory is not at all like a video recording that a witness need only replay to remember what happened. Human memory is far more complex.” The instructions encourage jurors to consider different factors that affect eyewitness testimony, such as the effects of stress on recall.

“What is impressive about these instructions is that, unlike past ones, which might have told jurors that they could take into account the state of mind of the witness or the cross-racial nature of the identification, the new instructions educate the juror about how to take these factors into account,” write Schacter and Loftus in Nature Neuroscience. “Neuroscientific evidence concerning memory, together with evidence from cognitive psychology, could help in educating jurors and other participants in the legal system generally about the nature of memory,” they further write. “However, we draw a distinction between such a general educational role and the application of neuroimaging data to individual cases.”

CNS talked more with Schacter about this recent article and related issues, including on the fallibility of our memories, new lines of research in understanding memory distortion, and the future of the science for application to legal settings.

CNS: In general, why is it so difficult to accurately evaluate our memories?

Schacter: Memories are difficult to evaluate in part they are constructions that reflect how we interpret our experiences, rather than being literal, photographic reproductions of experiences. It’s also the case that the act of retrieving our memories and talking about them with others can distort memories in subtle ways. Also, memory and imagination depend on many of the same cognitive and neural processes, making it easy to confuse an imagined experience for an actual remembered experience.

CNS: How did your work on memory lead you into the area of neuroscience and the law? How did you become interested in the topic?

Schacter: I began working on the cognitive neuroscience of memory distortion in the mid-1990s. Our group carried out a number of neuroimaging studies focused on questions concerning brain activity that could distinguish true memories from false memories. Although our work was motivated primarily by theoretical considerations, given the importance of memory accuracy and distortion in the legal arena, it is hardly possible to avoid making those connections. Beginning in the late 1990s, I have been asked regularly to speak to groups of lawyers, judges, and legal scholars about the cognitive neuroscience of memory and its possible implications for the courtroom, which further fueled my interest.

CNS: What do you think are the 2-3 most exciting lines of research in the field of memory distortion?

Schacter: I’m excited by work that is exploring the relationship between remembering past experiences and imagining future experiences, and what that might tell us about the nature and basis of memory distortion. We think that memory is well-suited to constructing simulations of possible future experiences because it allows flexible access to elements of past experiences, which may be recombined to imagine novel future events. But that very flexibility may also result in memory distortions when we mistakenly combine elements from different events.

Research on the neural basis of how memories change over time is also compelling. We know that memories can change over time but are only beginning to learn how such changes might be related to brain activity. Research on reconsolidation – the notion that when memories are reactivated, they temporarily enter an unstable state and must be consolidated anew – should provide important clues concerning how and why memories change over time.

CNS: How would you like to see the field evolve? Should it eventually include more practical applications such as in the courtroom?

Schacter: It is gratifying to see that cognitive research on memory distortion and eyewitness testimony is having an impact on the legal system, as illustrated by the new, science-based jury instructions now in place in New Jersey. As discussed in the commentary I co-authored with Elizabeth Loftus in Nature Neuroscience, we are of two minds concerning the role on cognitive neuroscience. On the one hand, we are skeptical that neuroimaging has reached a point where it can be used in the courtroom to distinguish between true and false memories for single events in individuals. On the other hand, we do think that cognitive neuroscience research could help jurors and other participants in the legal system to better understand why it is that memory does not operate like a video recorder, and why it is sometimes prone to error and distortion.

CNS: What is the best piece of advice you would want to give someone on jury duty to keep in mind when considering a case that involves eyewitness testimony?

Schacter: Don’t naively assume that everything an eyewitness remembers is accurate. Keep in mind that memory does not work like a video recorder, and do your best to critically evaluate eyewitness testimony.

A symposium on neuroscience and the law will take place April 16, 2013, at the CNS annual meeting in San Francisco. Researchers will discuss the promise and the limits of the science for application in legal and forensic settings.

—

Media contact: Lisa M.P. Munoz, CNS Public Information Officer, cns.publicaffairs@gmail.com