Relationship the PA/PD ratio at the eCAP and cortical level.

For each acute animal, the ratio between the eCAP maximum amplitude triggered by the PA and PD strategy was plotted against the ratio between the strength of all cortical responses obtained with the PA and the PD strategy. At the level of the eCAP, the last 3 points of the growth function shown in Fig 5 were considered; at the cortical level, the responses of all the electrodes responding at the 3 last charge levels were pooled together. There was a significant correlation between the values of the PA/PD eCAP and the values of the PA/PD cortex (r = 0.895; p<0.001) indicating that the strategy producing the largest eCAP amplitude, also produced the largest cortical responses.