Fig. 1

Study design. Top panel: procedure of the study phase and test phase. To ensure proper encoding and memory strength, participants went through three training tasks (i.e., questionnaire, jigsaw puzzle, and flashcard), and were then tested for their memory in the pretest. Participants who completed the pretest with accuracy above 90% would continue to perform the formal reaction time-based Concealed Information Test (RT-CIT). Those with accuracy below 90% had to go back to the flashcard task, and then perform the pretest again until their pretest accuracy was over 90%. Middle panel: trial procedure in the test phase. Note that the actual display of “seen” and “never seen” (or “have not seen”) in the experiment was written in Traditional Chinese. Bottom panel: example of 12 angular rotations of one item. The presentation angles are defined such that the inward profile view is always 0°, and so on. During the study phase, participants saw only one view, and were tested with all views later in the test phase