Figure 3. Two representative SC neurons (A, B) showing different sensitivity for visual and auditory stimuli.

(mean discharge rate +/− standard error with respect to the horizontal eye-centered target location or movement amplitude; S R² and G R² refer to the Sigmoidal and Gaussian R² values). For three out of the four visual responses (upper panels), the fits of Gaussian function are significantly better than those of sigmoidal function (the sensory R² values for A and B, and the motor R² value for B; bootstrap analysis, p<0.05). In contrast, for the auditory responses (lower panels), the fit of both functions are about equally good (bootstrap analysis, p > 0.05).