Figure 3.

(A) Psychophysical electrical detection thresholds as a function of pulse rate (lower abscissa) and interpulse interval (upper abscissa) for two-pulse stimuli for the 13 subjects from part I. (B) Slopes of threshold versus pulse rate functions above 1000 pps (IPI < 1 ms) versus slopes below 1000 pps (IPI > 1 ms). Points below the diagonal indicate that the slopes of the functions above 1000 pps were steeper (more negative) than slopes below 1000 pps. Mean slopes for all animals are indicated by open circles on the X and Y axes. Slopes above 1000 pps were significantly steeper than those below 1000 pps (t = 4.31, p = 0.0002).