Spatial Memory of Body Linear Displacement: What Is Being Stored?

TLDR

Evaluating traveled distance is a common ability across animal species, and recent human studies show that head trajectory can be stored in spatial memory, yet how movement is stored remains unclear. Head trajectory in space is measured on the basis of converging signals from the visual, vestibular, and somatosensory systems, together with efferent copies of motor commands. Humans who reproduced passive linear whole-body displacement distances while blindfolded also reproduced velocity profiles, suggesting that a spatiotemporal dynamic pattern of motion is stored and can be retrieved using vestibular and somesthetic cues.

Abstract

The ability to evaluate traveled distance is common to most animal species. Head trajectory in space is measured on the basis of the converging signals of the visual, vestibular, and somatosensory systems, together with efferent copies of motor commands. Recent evidence from human studies has shown that head trajectory in space can be stored in spatial memory. A fundamental question, however, remains unanswered: How is movement stored? In this study, humans who were asked to reproduce passive linear whole-body displacement distances while blindfolded were also able to reproduce velocity profiles. This finding suggests that a spatiotemporal dynamic pattern of motion is stored and can be retrieved with the use of vestibular and somesthetic cues.