Abstract
Some of the functional properties of different otolith-ocular reflexes are discussed in this chapter, such as the linear vestibulo-ocular reflexes, which are activated by linear acceleration. The latter part of the chapter focuses on the interaction of otolith and canal signals during rotatory head movements. Stabilization of the line of sight and maintenance of spatial orientation requires appropriate transformation of sensory inputs of different modalities to oculomotor output. Rapid information about head movements and orientation in space is provided by the vestibular organs. The utricular and saccular otolith organs detect linear accelerations of the head, and hence convey information about translatory head movements as well as about head orientation relative to gravity, while the semicircular canals, activated by head angular accelerations, provide afferent information. Otolith signals interact with semicircular canal signals in at least two important ways involving the velocity storage system. First, otolith signals are processed to complement the canal-ocular reflexes at frequencies of head rotations below 0.1 Hz. Second, static otolith input interacts through the velocity storage integrator with head velocity signals to provide a spatial reference about head angular velocity. The otolith organs provide complementary signals that are used to detect the direction of the head rotation in space, i.e. relative to gravity, as well as eccentricity of rotation during fast head movements. Dynamic otolith signals can initiate appropriate transformations of canal-driven head velocity signals to account for eccentricity of ocular rotation and target distance.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call