Abstract
In many everyday situations, we perform mental rotation on different objects. While it is clear that visual working memory (VWM) participates in mental rotations, we argue that the exact role of VWM in this process is yet to be determined. One reason is that classic mental rotation tasks usually involve judging whether a stimulus is presented in its mirrored form or in its regular form. Stimuli are rotated in the page plane, or both in the page plane and mirrored. Thus, the task actually involves two different processes of rotation. We separated them by developing a unique task for each rotation type. We collected EEG data and used the Contralateral Delay Activity (CDA) as an indicator of VWM involvement. In Experiment 1 we used a task involving both rotation in the page plane (degrees-rotation) and mirror-rotation. In Experiment 2 we isolated mirror-rotation and in Experiment 3 we isolated degrees-rotation. Experiment 1 results suggested different VWM involvement according to the degrees of rotations when the item was not mirrored, while the mirror-rotation’s trials were all at ceiling in terms of VWM, regardless of their rotation degree. Experiment 2 results showed an indication for VWM involvement uniquely related to mirror rotation. Experiment 3 results showed different VWM involvement that is specifically related to the degree of rotation. Our results suggest that there is a difference in VWM involvement while performing different rotation processes, even though there is just one object that is being held in VWM.