Postural and eye-blink indices of the defensive startle reflex.
Postural and eye-blink reactions to acoustic startle probes were examined in 24 volunteers, who completed two blocked conditions (baseline, startle). A postural reaction during the startle condition demonstrated a reflexive movement in the anterior-posterior direction, which was not observed during the baseline condition. This reflexive response was positively associated with the eye-blink reflex, such that larger blink magnitude related to greater posterior movement. These findings were not observed for postural movements in the medial-lateral direction. The results suggest that a measurable postural reaction may be observed following a startling acoustic stimulus, which may reflect generalized bodily flexion associated with a preparatory behavioral response.
Hillman
Charles H
CH
Department of Kinesiology, University of Illinois at Urbana-Champaign, 213 Louise Freer Hall, 906 S. Goodwin Avenue, Urbana, IL 61801, USA. chhillma@uiuc.edu
Hsiao-Wecksler
Elizabeth T
ET
Rosengren
Karl S
KS
D000161:Acoustic Stimulation / Q000379:methods; D000293:Adolescent; D000328:Adult; D001767:Blinking / Q000502:physiology*; D004576:Electromyography / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D009068:Movement / Q000502:physiology; D011187:Posture / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D013216:Reflex, Startle / Q000502:physiology*