A noninvasive technique for studying the neural processing of respiratory sensations will be used to assess changes in the affective unpleasantness component of dyspnea during a standardized loaded breathing task. Electroencephalography (EEG) will be used to measure respiratory related evoked potentials (RREPs) during loaded and unloaded breathing. The RREP recorded from EEG is a measurement of cerebral cortical activity, which is elicited by the activation of lung and muscle mechanoreceptors due to short inspiratory occlusions. Patients will be wearing EEG sensors [129 channel system, Electrical Geodesics Inc., Eugene, USA] and breathe through a breathing circuit with a non-rebreathing valve via a mouthpiece. The inspiration will be interrupted briefly for 150 milliseconds every two to six breaths by activation of the occlusion valve with pressurized air, which induces the RREP. Patients will be rating their perceived intensity and unpleasantness of dyspnea and intensity of occlusion on a Borg scale while inspiratory load and occlusion will be applied via a breathing valve. This method will be used to assess if there is less unpleasantness associated with a giving level of dyspnea elicited by a resistive breathing task and whether these changes are correlated with changes in the central processing of the dyspnea sensation.