Temporal differences in the detection of resistive and elastic loads to breathing.

Two series of experiments were conducted on 8 healthy subjects to test for temporal differences in the detection of added resistive and elastic loads. In one series of experiments, 5 resistive loads were presented for single inspirations for a total of 10 presentations each. Subjects pressed a signal marker as soon as possible if they detected the load. In the second series, 5 elastic loads were tested using the same protocol The detection time (Tdet) for threshold resistive loads (deltaR50) occurred in mid-inspiration near Vmax whereas the Tdet for threshold D loads (delta E50) occurred near the end of inspiration. The differences in the detection times were significant (P less than 0.001). With suprathreshold loads, detection times progressively decreased reaching a minimum value with total occlusion. These results demonstrate unique temporal differences in the patterns of sensory information generated by added resistive and elastic loads and suggest that the intensity of the information is flow dependent for resistive loads and volume dependent for elastic loads.