What Has Eye Tracking Taught Us About Criminal Identifications?
Researchers have now been using eye tracking for more than a century. This may be surprising to some but a quick look around web and you can see just where and when it started to show up. It’s led to numerous discoveries providing insight into how we think and feel. As a recent publication puts it, eye tracking has investigated a range of topics – not just the usability studies we see more and more of these days, but others such as the effect of weapon exposure, visual attention in anti-social personality disorder, and the role of expertise in deception detection (we wrote about that and alternatives for polygraph testing in another article). Researchers have recently started to use eye tracking to study eyewitness decision processes during criminal lineups, and a new paper reviews the use of eye tracking to identify suspects.
In testing, participants view a video of staged crime and are then tested with a lineup to identify the “criminal” from the video. The lineup typically features one suspect (who may or may not be guilty) and then a few extra “foil” faces to distract. The paper discusses how eye tracking may provide real time information about lineup decision processes as gaze can be continually monitored while the lineups are viewed.
As is standard practice in North America, criminal identification tasks are conducted in a simultaneous nature, showing the entire lineup at once and allowing the eyewitness to see all the photos at the same time. But lately, the paper says, some jurisdictions have begun to use sequential lineups, where suspect and foil photos are displayed one at a time, often utilizing video instead of a static photo.
Inevitably, the accuracy of the identification decisions varies greatly depending on the type of strategy used to make the decision. The simultaneous lineup is referred to as a relative decision strategy, and is considered to be more inaccurate than what would be known as an absolute strategy. Simultaneous lineups are associated with errors, as they involve comparisons among members. In the absolute strategy, participants cannot make direct visual comparisons of members. Interestingly, the rate of identifying the guilty suspect is also reduced as a result, but to a smaller extent compared to the reduction in incorrect identifications.
The article goes on to discuss eye tracking and identification decision making, and it’s quite an interesting read, especially if you’re into psychology and criminology.
Eye tracking and Eyewitness Memory
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