Figure 7. Monotonicity index methods and results.

An example neuron showing a drop-off in responses at the most contralateral target positions (sensory responses shown) (A). We compared the responses at the peak location to the responses at the most contralateral location (black dots) and expressed the result as a Z-score (inset). Data for the ipsilateral fixation was used for this analysis. B. The distribution of Z scores for each modality (grey bars), in comparison to the Z scores expected if the relationship between activity and target location is scrambled (Monte-Carlo simulation, black bars). The dotted lines illustrate the 95% confidence threshold; real Z scores to the right of this point are considered to show statistically significant decrements in activity for more peripheral targets (p<0.05) C. The proportion of neurons showing significant non-monotonicity. D. Same as C, but for targets limited to different cut-off points in our sampling range. The disparity between visual and auditory non-monotonicity is present for all cut-offs, and only with a 36 degree cutoff for sound does the level of non-monotonicity reach that seen for a 12 degree cutoff for visual stimuli.