Monday, 10 September 2012

A simple technique for improving eye-witness memory

Thanks to the foibles of human memory, eye-witness evidence is notoriously unreliable. One attempt to help the situation was the Cognitive Interview (pdf), conceived by psychologists in the 1980s. This involves strategies such as conducting the interview in a situation that matches the original crime context as closely as possible, and asking witnesses to remember events from multiple perspectives. Although highly effective, the Cognitive Interview can be impractical and it often goes unused. Now Annelies Vredeveldt and Steven Penrod have tested a far simpler technique for improving eye-witness memory - getting them to close their eyes. Lab research has already shown that this can be beneficial. Vredeveldt and Penrod took the technique out on the streets to see if it works there too.

Ninety-six undergrads signed up for what they thought was a study into "social interactions". In groups of up to four, they met two female researchers on a New York street corner. Shortly after the participants' arrival the two women started arguing and insulting each other. The altercation ended with one of the women knocking the other woman's papers to the ground and storming off.

After they'd witnessed the public spat, the participants were led away either to another street location or the psychology lab, both being five minutes' walk. Here they were asked to recall everything they could about the event, and then they were asked a series of questions about what happened. Half the participants were instructed to close their eyes during the recall and the interview (they weren't told why); the other half were not. The researchers ensured each of the staged arguments was caught on film so that the participants' answers could be checked for accuracy.

Overall, participants who closed their eyes recalled 37.6 per cent more useful visual information about the argument, and, in questioning, they produced 23.8 per cent more correct answers coded as having high detail. The advantage of having closed eyes was most pronounced for participants who were quizzed inside. This supports the idea that the technique works by helping participants to create the original context in their mind's eye. If it worked by helping reduce distraction, you'd think it would have had more of a benefit out on the street.

"From an applied perspective, the findings were promising," Vredeveldt and Penrod said. "In free recall, the effect size of the eye-closure effect for witnesses interviewed inside (d=.88) approached the effect size obtained with the Cognitive Interview.

"Given that the eye-closure instruction requires no training or additional interview time, it could prove to be a useful alternative [to the Cognitive Interview]," they added.


Annelies Vredeveldt, and Steven D. Penrod (2012). Eye-closure improves memory for a witnessed event under naturalistic conditions. Psychology, Crime and Law DOI: 10.1080/1068316X.2012.700313

Post written by Christian Jarrett for the BPS Research Digest.


  1. Interesting, many of us close our eyes to dilute interference of the thought process from the data pouring in from the sensors, in many cases, not only are the eyes closed, but also the ears, deep in thought we ignore the babble of noise that flows around us, we do the same with the skin when we are in pain, and so on.

    There are two things which could be happening here, one a shutdown of the sensors enables interruption free replay, which seems to be the basic premise of the paper, however there is another case.

    It could be that while the eyes are closed, interruption free processing as opposed to replay is taking place, the closed senses revs up the data processing speed. As to what is really happening only a brain scan can tell us, and perhaps we really do not have the tools that can tell us this.

    Also consider that humans have an inbuilt process for this, their blink, which gives the processing machinery the time to switch off the sensors and process any data overloads.

    There could be biological confirmation forthcoming, that a blink means more than a closure of the eye for lubrication and such mechanical purposes, perhaps it coordinates with a system triggered/coordinated dip in signal reading ability for the other senses too that enables interrupt free data processing.

    I always wonder if there is a study that connects blinking with understanding, that people who blink more can process data better or vice versa, as blink being an indicator of brain efficiency.

    We of course have long connected blinks to a blank mind, a mind that is slow, is there a scientific reason behind this?

  2. Nice technique. It was nice to have experience about improving eye-witness memory. Simply nice blog.!

  3. wow!that cool and Interesting.Thank you for sharing

