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Sensory convergence solves a motion ambiguity problem.

Authors :
Shaikh AG
Green AM
Ghasia FF
Newlands SD
Dickman JD
Angelaki DE
Source :
Current biology : CB [Curr Biol] 2005 Sep 20; Vol. 15 (18), pp. 1657-62.
Publication Year :
2005

Abstract

Our inner ear is equipped with a set of linear accelerometers, the otolith organs, that sense the inertial accelerations experienced during self-motion. However, as Einstein pointed out nearly a century ago, this signal would by itself be insufficient to detect our real movement, because gravity, another form of linear acceleration, and self-motion are sensed identically by otolith afferents. To deal with this ambiguity, it was proposed that neural populations in the pons and midline cerebellum compute an independent, internal estimate of gravity using signals arising from the vestibular rotation sensors, the semicircular canals. This hypothesis, regarding a causal relationship between firing rates and postulated sensory contributions to inertial motion estimation, has been directly tested here by recording neural activities before and after inactivation of the semicircular canals. We show that, unlike cells in normal animals, the gravity component of neural responses was nearly absent in canal-inactivated animals. We conclude that, through integration of temporally matched, multimodal information, neurons derive the mathematical signals predicted by the equations describing the physics of the outside world.

Details

Language :
English
ISSN :
0960-9822
Volume :
15
Issue :
18
Database :
MEDLINE
Journal :
Current biology : CB
Publication Type :
Academic Journal
Accession number :
16169488
Full Text :
https://doi.org/10.1016/j.cub.2005.08.009