Figure 6. SAC Signal Variability Is Attributable to AM Noise.

(A) Example effects of noise on response amplitudes from a simulated SAC varicosity. Three representative simulation rounds are indicated by separate colors. Arrows (top) and vertical lines (bottom) point to the estimated PD from each round. Noise-free PD is 0° (“Out”). Parameters for AM (A₁) and DM (A₂) noise types were set to replicate experimental SNR and σ_PD, respectively (left), and higher noise levels (right).

(B) Response variability at different noise levels (B₁, AM noise; B₂, DM noise). In (B₁), σ_PD was determined from 1,000 single-round repeats at each indicated SNR level. In (B₂), SNR was calculated from 1,000 simulated responses to motion at PD (0°) at each σ_PD level. Dotted lines and shaded areas indicate the experimentally measured values (mean ± SD).

See also Figure S5.