Effect of Seated Trunk Posture on Eye Blink Startle and Subjective Experience: Comparing Flexion, Neutral Upright Posture, and Extension of Spine

Erik Ceunen,Jonas Zaman,Johan W S Vlaeyen,Ilse Van Diest,Wim Dankaerts,Marc H.E De Lussanet

doi:10.1371/journal.pone.0088482

Abstract

Postures are known to be able to affect emotion and motivation. Much less is known about whether (affective) modulation of eye blink startle occurs following specific postures. The objective of the current study was to explore this. Participants in the present study were requested to assume three different sitting postures: with the spine flexed (slouched), neutral upright, and extended. Each posture was assumed for four minutes, and was followed by the administration of brief self-report questionnaires before proceeding to the next posture. The same series of postures and measures were repeated prior to ending the experiment. Results indicate that, relative to the other postures, the extended sitting posture was associated with an increased startle, was more unpleasant, arousing, had smaller levels of dominance, induced more discomfort, and was perceived as more difficult. The upright and flexed sitting postures differed in the level of self-reported positive affect, but not in eye blink startle amplitudes.

Highlights

Both dynamic and static body posture are understood to serve a communicative role, as does verbal content, vocal tonality, vocal volume, and facial expression [1]
Darwin [2] already documented that body posture communicates emotional states
It is plausible that the emotional well-being of office workers worldwide is affected by frequently sitting in a slouched posture for extended periods of time given the documented effects of such a posture [7], potentially resulting in more than just back pain

Summary

Introduction

Both dynamic and static body posture are understood to serve a communicative role, as does verbal content, vocal tonality, vocal volume, and facial expression [1]. Darwin [2] already documented that body posture communicates emotional states. This is understood to be a consequence of different emotions having different effects on body posture [3]. It is plausible that the emotional well-being of office workers worldwide is affected by frequently sitting in a slouched posture for extended periods of time given the documented effects of such a posture [7], potentially resulting in more than just back pain. Posture is potentially a confounding variable; it can affect outcomes of similar studies on emotion differently [8]. The body posture-emotion association is an avenue of research that needs further investigation

Objectives

Results

Conclusion