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. 2021 Mar;58(3):e13752.
doi: 10.1111/psyp.13752. Epub 2020 Dec 21.

When reflex reactions oppose voluntary commands: The StartReact effect on eye opening

Josep Valls-Solé  1 , Juan M Castellote  2   3 , Markus Kofler  4 , Tereza Serranová  5 , Viviana Versace  6   7 , Stefania Campostrini  6   7 , Michela Campolo  8
Affiliations

When reflex reactions oppose voluntary commands: The StartReact effect on eye opening

Josep Valls-Solé et al. Psychophysiology. 2021 Mar.

Abstract

A startling auditory stimulus (SAS) induces a reflex response involving, among other reactions, a strong contraction of the orbicularis oculi muscle (OOc) and subsequent eye closure. A SAS also induces the StartReact effect, a significant shortening of reaction time in subjects ready for task execution. We examined the obvious conflict appearing when a StartReact paradigm requires participants with eyes closed to open their eyes to look for a visual target. We recorded OOc EMG activity and eyelid movements in healthy volunteers who were instructed to open their eyes at perception of a somatosensory imperative stimulus (IS) and locate the position of a Libet's clock's hand shown on a computer screen at 80 cm distance. In 6 out of 20 trials, we delivered a SAS simultaneously with the IS. The main outcome measures were reaction time at onset of eyelid movement and the time gap (TG) separating subjective assessment of the clock's hand position from real IS issuing. Control experiments included reaction time to eye closing and target location with eyes open to the same IS. Reaction time was significantly faster in SAS than in noSAS trials and slower for eye opening than for eye closing in both conditions. In the eye-opening task, TG was significantly shorter in SAS with respect to noSAS trials, despite the presence of the SAS-related burst in the OOc before EMG cessation. Our results indicate that the StartReact effect speeds up eye opening and location of a target in the visual field despite the startle reaction opposing the task.

Keywords: Libet's clock; StartReact effect; eyelid movement; orbicularis oculi EMG; startle; visual target.

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References

REFERENCES

    1. Alibiglou, L., & MacKinnon, C. D. (2012). The early release of planned movement by acoustic startle can be delayed by transcranial magnetic stimulation over the motor cortex. Journal of Physiology, 590(4), 919-936. https://doi.org/10.1113/jphysiol.2011.219592
    1. Anzak, A., Tan, H., Pogosyan, A., & Brown, P. (2011). Doing better than your best: Loud auditory stimulation yields improvements in maximal voluntary force. Experimental Brain Research, 208(2), 237-243. https://doi.org/10.1007/s00221-010-2474-1
    1. Aramideh, M., Ongerboer de Visser, B. W., Devriese, P. P., Bour, L. J., & Speelman, J. D. (1994). Electromyographic features of levator palpebrae superioris and orbicularis oculi muscles in blepharospasm. Brain, 117(1), 27-38. https://doi.org/10.1093/brain/117.1.27
    1. Brown, P., Rothwell, J. C., Thompson, P. D., Britton, T. C., Day, B. L., & Marsden, C. D. (1991). New observations on the normal auditory startle reflex in man. Brain, 114(4), 1891-1902. https://doi.org/10.1093/brain/114.4.1891
    1. Carlsen, A. N., Almeida, Q. J., & Franks, I. M. (2012). Startle decreases reaction time to active inhibition. Experimental Brain Research, 217(1), 7-14. https://doi.org/10.1007/s00221-011-2964-9

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