The quantification of respiratory sensations by normal subjects

Area of Science:

• * Psychophysics
• * Respiratory Physiology
• * Neuroscience

Background:

• * Stevens' psychophysical power law describes the relationship between stimulus intensity and perceived magnitude.
• * Understanding the sensory perception of respiratory variables is crucial for respiratory control research.

Purpose of the Study:

• * To determine the exponent (n) of Stevens' power law for four key respiratory variables: tidal volume (VT), inspiratory flow (V), ventilation (Ve), and frequency (f).
• * To investigate the neurophysiological mechanisms underlying the perception of respiratory sensations.

Main Methods:

• * Open magnitude scaling technique applied to normal subjects.
• * Measurement of perceived magnitude against physical magnitude for VT, V, Ve, and f.

Main Results:

• * Mean exponents (n) were calculated for each variable: VT (1.14 ± 0.08), V (1.13 ± 0.15), Ve (1.28 ± 0.11), and f (1.04 ± 0.15).
• * These exponents indicate an expanded sensory scale for judging respiratory variables.
• * Similar exponents for VT and V suggest a potential shared sensory mechanism.

Conclusions:

• * The human perception of respiratory variables like tidal volume and airflow utilizes an expanded sensory scale.
• * Afferent information from receptors influenced by respiratory muscle activity likely mediates the sensation of respiratory volume.
• * Further research is warranted to elucidate the specific neurophysiological pathways involved.