The relationship between respiratory-related evoked potentials and the perception of inspiratory resistive loads

This study investigated the relationship between resistive load magnitude, load magnitude estimation, and the respiratory-related evoked potential. In Part 1, 10 healthy subjects estimated the magnitude of five inspiratory re sistive loads. Two subjects were shown to have a markedly reduced slope of the magnitude estimation-resistive load relationship and were suggested to be "poor perceivers" of respiratory stimuli. In Part 2, evoked potentials w ere recorded from the same 10 subjects using the same resistive loads as Pa rt 1. A log-log plot of the group averaged P1 amplitudes showed a linear re lationship with resistive load. Aberrant P3 components were seen in the 2 p oor perceiving subjects and one of the 2 showed no late response. In the ot her 8 subjects, P3 varied as a function of resistive load, being augmented to larger loads. These results provide evidence that P3 may be a key index of the perception of respiratory sensitivity and effort.