Affective modulation of swallowing rates: unpleasantness or arousal?

OBJECTIVE

It has been observed that spontaneous swallowing rates are modulated by the affective state. Affect-induced swallowing may be an important biobehavioral factor in gastrointestinal disorders. However, previous studies failed to distinguish between pleasantness and arousal effects and did not analyze gender effects.

METHOD: We analyzed swallowing rates in 42 participants (22 women) who viewed 3 blocks of 12 affective pictures preselected for inducing positive, negative, and neutral affect. Swallowing rate was measured by brief and rapid resistance increases in forced oscillation measurements indicating closure of the glottis. In addition, participants rated pleasantness and arousal for each individual picture.

RESULTS

Cumulative swallowing rates were lower during positive and neutral than negative picture blocks. This effect was only observed in women. Ratings confirmed earlier findings with picture material.

CONCLUSION

Both pleasantness and arousal interact to modulate swallowing rates. The role of gender in moderating affect-induced swallowing requires further research.