How can we help witnesses to remember more? It's an (eyes) open and shut case.

Five experiments tested the idea that instructing a witness to close their eyes during retrieval might increase retrieval success. In Experiment 1 participants watched a video, before a cued-recall test for which they were either instructed to close their eyes, or received no-instructions. Eye-closure led to an increase in correct cued-recall, with no increase in incorrect responses. Experiments 2-5 sought to test the generality of this effect over variations in study material (video or live interaction), test format (cued- or free-recall) and information modality (visual or auditory details recalled). Overall, eye-closure increased recall of both visual detail and auditory details, with no accompanying increase in recall of false details. Collectively, these data convincingly demonstrate the benefits of eye-closure as an aid to retrieval, and offer insight into why hypnosis, which usually involves eye-closure, may facilitate eyewitness recall.