Nonlinear behavior of vestibulo-only cells.

Cells in the vestibular nucleus are assumed to behave as linear systems. We tested this hypothesis by testing the verity of two principles, those of superposition and homogeneity. Recordings were obtained from vestibulo-only cells of two rhesus monkeys undergoing translations, rotations, and off-axis (eccentric) rotations. This was done for several frequencies (1–5 Hz for translation and 1–4 Hz for rotation) and velocities. The sensitivity of all cells decreased in response to an increase in velocity (FIG. 1). In addition, this decrease was accompanied by an increase in the bias. This was true for all cells and for all paradigms, although the effect was more pronounced