The present study aimed to explore inspiratory motor drive as measured by inspiratory occlusion pressure (P100)
during affective picture viewing. P100 is the decrease inmouth pressure that develops 100 ms after an inspiratory effort
against a closed breathing circuit. The P100 is a measure of the ‘‘central respiratory drive.’’ Seventy-eight healthy
women viewed four pictures series (160 s) varying in content: neutral, positive, threat, or pain. They also rated each
picture series on pleasantness and arousal. An occlusion was applied at the onset of inspiration in 33% of the breaths.
The threat and the pain picture series were associated with an increased P100 and were rated as most unpleasant and
highest in arousal.We conclude that inspiratorymotor drive is affectively modulated and is ameasure of the respiratory
response to threatful stimuli.
Descriptors: Respiration, Inspiratory occlusion pressure, P100, Inspiratory motor drive, Affective picture viewing