Large changes in the visual field often go undetected, an effect referred to as change blindness. We investigated change blindness for an eyewitness event to examine its potential influence on identification accuracy and confidence.Methods.
Participants viewed a video that started with an innocent person walking through a building and finished with another person committing a theft. Participants subsequently attempted the thief's identification from a line-up that contained either the thief or the innocent person from the video.Results.
Most viewers (64%) experienced change blindness and were unaware of the person change. Overall identification accuracy in the change blindness group was significantly lower than in the change detection group. The decrease in accuracy in the change blindness group was primarily driven by poor performance when the line-up did not contain the thief. However, rather than misidentifying the innocent from the video, most witnesses who experienced change blindness misidentified a filler. Although change detection did not lead to a significant increase in correct identifications, it did lead to a significant increase in post-identification confidence.Conclusions.
Our findings suggest that (1) although change blindness increases misidentifications, under these conditions witnesses primarily misidentify known innocents who are not at risk of wrongful conviction; and (2) confidence is inferred not only from recognition strength but also from how well observers believe the event was encoded.