Critical conditions for hyperventilation responses - The role of autonomicresponse propositions during emotional imagery

Hyperventilation is often conceived of as part of a fight-or-flight respons e, triggered by situations with high arousal and negative valence. However, a previous study using emotional imagery found hyperventilation responses during imagery of high-arousal scenes regardless of their valence. Those im agery scripts contained suggestions of autonomic activity, which may have p artly induced or enhanced the hyperventilatory responsivity. The present st udy used four emotional scripts-depicting relaxing, fearful, depressive, an d pleasant situations-without suggestions of autonomic or respiratory respo nses. After each imagery trial, participants rated their imagery for valenc e, arousal, and vividness. Fractional end-tidal carbon dioxide (FetCO(2)), inspiratory and expiratory time, tidal volume, and pulse rate were measured in a non-intrusive way. Results showed significant FetCO(2) drops during t he fearful and pleasant scripts, However, this effect was much smaller comp ared to imagery scripts with autonomic response propositions. Participants imagining scripts without autonomic response information found it harder to imagine the scripts vividly and reported lower levels of subjective arousa l.