Spatial memory enhances the precision of angular self-motion updating.

Humans are typically able to keep track of brief changes in their head and body orientation, even when visual and auditory cues are temporarily unavailable. Determining the magnitude of one's displacement from a known location is one form of self-motion updating. Most research on self-motion updating during body rotations has focused on the role of a restricted set of sensory signals (primarily vestibular) available during self-motion. However, humans can and do internally represent spatial aspects of the environment, and little is known about how remembered spatial frameworks may impact angular self-motion updating. Here, we describe an experiment addressing this issue. Participants estimated the magnitude of passive, non-visual body rotations (40 degrees -130 degrees ), using non-visual manual pointing. Prior to each rotation, participants were either allowed full vision of the testing environment, or remained blindfolded. Within-subject response precision was dramatically enhanced when the body rotations were preceded by a visual preview of the surrounding environment; constant (signed) and absolute (unsigned) error were much less affected. These results are informative for future perceptual, cognitive, and neuropsychological studies, and demonstrate the powerful role of stored spatial representations for improving the precision of angular self-motion updating.