Respiratory related evoked potential measures of cerebral cortical respiratory information processing.

Normal breathing is usually not sensed by the individual. Individuals become aware of their breathing at the cognitive level when breathing pattern is manipulated. Airway obstruction activates lung and muscle mechanoreceptors that project to the somatosensory cortex. Cortical neuronal activation in the somatosensory cortex by inspiratory occlusions can be measured by scalp surface electrodes in humans. The averaged signal was defined as the respiratory related evoked potential (RREP). Six RREP peaks, Nf, P1, N1, P2, N2 and P300 have been studied in the averaged EEG trace. Voluntary attention, background loads, and disease state were found to modulate the RREP. Respiratory sensory gating was demonstrated with the RREP using different levels of intensities and frequencies of respiratory stimuli. Future studies are needed to investigate the effects of psychological states, such as attention and emotion, as well as non-respiratory modalities, such as visual, auditory, and tactile sensations, on the RREP.