At suprathreshold levels louder electrical pulses can sometimes evoke smaller neural responses

Evidence

Closer inspection of the data revealed that the input/output growth functions sometimes had non-monotonic shapes. An example obtained for G7 1 month after deafening is illustrated in Fig. 4c for RPS-A and RPS-C. The function for RPS-C shows, at some point in the dynamic range, a decrease in response amplitude with increases in level. In this case, the cathodic pulse was more effective than the anodic pulse at low levels but less effective at high levels. Such non-monotonicities were observed in seven of the ten subjects but only in about 13 % of the cathodic and 4 % of the anodic growth functions. Furthermore, they did not always occur for the same pulse shape across sessions. — Dijk, Pim van, Physiology, Psychoacoustics and…, 2309

Categorization

• XREF: Reverses the intuitive monotonic input-output assumption; relates to earlier reading on compression and nonlinear gain in the auditory system.