Relationship between resistive loads and P-1 peak of respiratory-related evoked potential

This study investigated the relationship between resistive-load (Delta R) magnitude, the first; positive peak (P-1) amplitude of the respiratory-related evoked potential (RREP), and load-magnitude estimation (ME). The first experiments determined the subject's (n = 9) ME of five Delta R magnitudes randomly presented at the onset of an inspiration or by interrupting an inspiration. No significant differences mere found in the slopes of the two different presentations, but the subjects estimated the interrupted inspiratory loads to be of lesser magnitude than loads presented at the onset of the breath. In the second series of experiments, the subject's; (n = 6) RREPs were recorded in response to three Delta R magnitudes. The amplitude of the short-latency P-1 peak of the RREP significantly increased with increases in the Delta R magnitude. A log-log plot of the group-averaged P-1 amplitudes showed a linear relationship with Delta R. These results were consistent with the hypothesis that the perceptual magnitude of the respiratory load was related to the P-1 amplitude of the RREP, suggesting the physical magnitude of the load-related stimulus was correlated with the amplitude of the cortical neural activation.