Maintaining readiness for mental rotation interferes with perceptual processes in children but with response selection in adults

Previous work revealed that mental rotation is not purely inserted into a same-different discrimination task. Instead, response time (RT) is slowed to upright stimuli in blocks containing rotated stimuli compared to RT to the same upright stimuli in pure upright blocks. This interference effect is a result of maintaining readiness for mental rotation. In two experiments we investigated previous evidence that these costs depend upon distinct sub-processes for children and for adults. In Experiment 1, the maintaining costs turned out to be independent of the visual quality of the stimulus for adults but not so for children. Experiment 2 revealed that the maintaining costs were greatly reduced for adults when they performed mental rotation as a go-no-go task, but not so for children. Taken together, both experiments provide evidence that whereas perceptual processes seem to be important for school-age children to maintain readiness for mental rotation, response selection is relevant for adults.