Voluntary Control of Thoracic and Abdominal Respiratory Movements

After being preliminarily taught a technique of thoracic and abdominal respiration, 12 young men reproduced, using or not using visual control of the pneumogram, the specified tidal volumes corresponding to the spontaneous and the doubled ones at the expense of either thoracic (by repressing abdominal movements) or abdominal (by repressing thoracic movements) respiration. The subjects reproduced tidal volumes more exactly during thoracic respiration and repressed thoracic movements more successfully during abdominal respiration. The external feedback (visual control) enhanced the effectiveness of volitional repression of abdominal respiratory movements but did not substantially affect the effectiveness of repression of thoracic movements.