A parametric study of the separate contributions of the tactile and acoustic components of airpuffs to the blink reflex.

Airpuffs are often used as blink reflex eliciting stimuli, but the airpuff makes an abrupt noise when it leaves the tube. The present study investigated the effects of the tactile and acoustic components of airpuffs on the blink reflex in 18 human subjects. Subjects received airpuffs to the temple at 10.3, 20.7 and 31.0 kPa in a within-subjects design. The airpuff-associated noise was attenuated (Airpuff + Attenuated noise) or airpuffs were presented without noise-attenuation (Airpuff+ Unattenuated noise) in two conditions. In the third condition, the airpuff was directed away from the temple to eliminate the tactile component of the airpuff (Noise alone). Reflexes were larger, more probable and faster to the Airpuff+ Unattenuated noise compared to the Airpuff+ Attenuated noise. This indicates that there is an excitatory influence from the acoustic component of the airpuff. The findings suggest that researchers should reduce the acoustic component of airpuffs in studies that use airpuffs as reflex eliciting stimuli.