School of Human Kinetics, University of Ottawa, 125 University Private, Ottawa, ON, Canada.
Sci Rep. 2021 Dec 8;11(1):23612. doi: 10.1038/s41598-021-02825-8.
In a simple reaction time task, the presentation of a startling acoustic stimulus has been shown to trigger the prepared response at short latency, known as the StartReact effect. However, it is unclear under what conditions it can be assumed that the loud stimulus results in response triggering. The purpose of the present study was to examine how auditory stimulus intensity and preparation level affect the probability of involuntary response triggering and the incidence of activation in the startle reflex indicator of sternocleidomastoid (SCM). In two reaction time experiments, participants were presented with an irrelevant auditory stimulus of varying intensities at various time points prior to the visual go-signal. Responses were independently categorized as responding to either the auditory or visual stimulus and those with or without SCM activation (i.e., SCM+/-). Both the incidence of response triggering and proportion of SCM+ trials increased with stimulus intensity and presentation closer to the go-signal. Data also showed that participants reacted to the auditory stimulus at a much higher rate on trials where the auditory stimulus elicited SCM activity versus those that did not, and a logistic regression analysis confirmed that SCM activation is a reliable predictor of response triggering for all conditions.
在简单反应时间任务中，呈现令人惊讶的听觉刺激已被证明会在短潜伏期引发准备好的反应，即 StartReact 效应。然而，目前尚不清楚在什么条件下可以假定大声刺激会导致反应触发。本研究的目的是探讨听觉刺激强度和准备水平如何影响无意识反应触发的概率以及在胸锁乳突肌（SCM）的惊跳反射指标中的激活发生率。在两个反应时间实验中，参与者在视觉 Go 信号之前的不同时间点接受不同强度的无关听觉刺激。反应独立地分为对听觉或视觉刺激的反应，以及有或没有 SCM 激活（即 SCM+/-）的反应。随着刺激强度的增加和更接近 Go 信号的呈现，反应触发的发生率和 SCM+试验的比例均增加。数据还表明，与未引起 SCM 活动的试验相比，参与者在听觉刺激引起 SCM 活动的试验中对听觉刺激的反应速度要高得多，逻辑回归分析证实，对于所有条件，SCM 激活是反应触发的可靠预测指标。
