Effect of referencing on PSDs and slopes. (A) Mean PSDs (computed between 500 and 0 ms before stimulus onset; left plot) and the corresponding slopes (right plot) calculated for the single-wire reference (red), average reference (green), bipolar reference (blue), and CSD (orange) for monkeys 1 and 2. The number of electrodes averaged is given in the inset in the first and third columns. (B) Mean PSDs (left plot) and slopes (right plot) using bipolar reference where the reference electrode was taken from varying distances from the recording electrode (distance ranges in m and the number of electrode pairs are shown in the inset in the first and third columns). The insets in the first and third columns show the PSDs between 0 and 100 Hz, the typical range used in most LFP studies.