1. By the use of Signal Detection Theory techniques, resistive load detection sensitivity was estimated in six normal subjects, and compared with detection when the chest cage was strapped in the position of full expiration.
2. With chest cage restriction there was both a decrease in detection sensitivity and an increase in the willingness to report the presence of an added load to breathing.
3. This suggests that the similarity of detection in chest clamping and control previously reported was due partly to increased detection bias with chest clamping.
4. These results have implications concerning the dependence of detection on afferent information from the chest wall.