CrimeScience Helps Improve Eyewitness Testimony

Published 28 January 2020

As we move through the world, looking at objects and people, we generally trust that we are accurately perceiving what’s out there. But research has shown that part of what we see sometimes originates in our own minds — that our brains fill in blanks in our vision based on our expectations or past experiences. Now science — and the insights it provides about the pitfalls in our vision and memory — is improving the way eyewitness testimony is taken and used.

As we move through the world, looking at objects and people, we generally trust that we are accurately perceiving what’s out there. But research has shown that part of what we see sometimes originates in our own minds — that our brains fill in blanks in our vision based on our expectations or past experiences.

While the effects of this tendency are often helpful, they can sometimes be tragic — as when witnesses to a crime mistakenly believe they saw somebody who they did not. In over 70 percent of the 360+ cases in which a person convicted of a crime was later exonerated by DNA testing, at least one mistaken eyewitness identification was involved, according to the Innocence Project.

Now science — and the insights it provides about the pitfalls in our vision and memory — is improving the way eyewitness testimony is taken and used. Over the past few years, police departments in at least 19 states have implemented safeguards that can help reduce the chance of errors, a shift due in part to a report released in late 2014 by the National Academies, Identifying the Culprit: Assessing Eyewitness Identification

NAS says that National Academy of Sciences member Thomas Albright, a neuroscientist at the Salk Institute for Biological Studies, co-led the 14-person committee that developed the report. Albright studies how our eyes and brains process, construct, and remember what we see. He drew upon this knowledge as he and the committee studied how eyewitnesses can get things wrong — and how to improve the odds that they will get things right.

The Shifting, Subjective Nature of Sight
In his lab at the Salk Institute in California, Albright and his colleagues study how our brains take in and shape what we see. In studies with animals and people, the researchers use instruments to monitor the activity of brain cells as something is viewed — allowing inferences about specific parts of the brain that enable humans to see particular things, such as the color red or the motion of an object. 

Part of the lab’s work has focused on how context affects people’s perceptions. “As a simple example, we’ve known for centuries that the perceived color of a patch of light will depend heavily on the color that surrounds it,” says Albright. “This is partly why if you want to paint your walls at home, it’s difficult to choose a paint color at the paint store and have