Effects of affective picture viewing and imagery on respiratory resistance in nonasthmatic individuals

We studied the modulation of oscillatory resistance (R(os)) by viewing and imagery of affective pictures. Thirty nonasthmatic participants viewed 36 affective slides precategorized as positive, neutral, and negative in valence. Each picture was presented for 15 s, followed by an imagery epoch of 15 s. R(os), facial EMGs, respiration, skin conductance response, heart period, and respiratory sinus arrhythmia were measured throughout the session, as well as viewing time and ratings of pleasure, arousal, and interest. Increases of R(os) were observed for negative pictures, and little changes for positive or neutral pictures. Other physiological parameters did not mirror this response pattern, leaving no clear indication for a ventilatory or vagal origin of R(os) changes. Overall differences between behavioral contexts of visual processing and imagery revealed evidence for a coupling of cardiac and respiratory responses, which included changes in R(os). The findings in R(os) are discussed in the light of earlier discrepant findings on the affective modulation of airway resistance and cardiac activity.