Mutual interferences between automatic ongoing spatial-updating with self-motion and source recall

Recent models suggest that spatial updating of position with self-motion is a key component of remembering. In the first experiment, participants simultaneously performed a spatial task and a source recall. In the spatial task, blindfolded participants rotated to a new orientation and then pointed to an object's position. They pointed either from their new orientation (in the updating condition), or as if they were still in their starting orientation (in the ignoring condition). In the updating condition, participants had to accurately integrate their own movement whereas, in the ignoring condition, they had to ignore it. If spatial updating and episodic memory rely on the same network, only the updating condition should interfere with source recall. Results are in line with this prediction. A second experiment using a semantic memory task instead of source recall showed no interference effect. These results suggest that episodic memory and spatial updating are functionally linked.