Otolith-organ mechanics: lumped parameter model and dynamic response.

The otolith organs comprise a second-order system whose response is overdamped and whose dynamics can be expressed by two time constants. The long time constant has been experimentally measured at 10 s. The short time constant is approximately 0.0002 s using a maximum mechanical displacement criterion for the otoconial layer. With these two values determined, the system dynamic response indicates that, between the two system corner frequencies, the peripheral sensory cells (primary Type II cells) report skull velocity information to the central nervous system, and striolar cells (primary Type I cells) report skull acceleration information to the central nervous system. Below the lower corner frequency, peripheral sensory cells report skull acceleration information to the central nervous system, and striolar sensory cells report rate of change of acceleration information to the central nervous system.