突发强声刺激下神经肌肉反应时间优势的研究

目的对突发强声刺激下神经肌肉活动潜伏期及其较之意识反应的时间优势进行研究,探讨刺激强度变化对该优势的影响。方法实验一:以110 dB强声低调纯音刺激诱发神经肌肉活动,通过表面肌电技术考察突发性强刺激下神经肌肉活动相对于意识反应的潜伏期及其时间优势;实验二:在实验一结果的基础上,测定不同强声刺激(90 dB,100 dB,110 dB)对诱发神经肌肉活动影响的变化。结果 1)当背景刺激为55～60 dB,诱发刺激为110 dB时,突发强声刺激条件下神经肌肉的反应潜伏期显著快于意识反应活动,时间优势可达1178 ms。2)90 dB组、100 dB组、110 dB组下产生惊跳反射的受试者人数存在显著差异(P<0.01),但3组间的反应潜伏期、最大振幅及时间优势效应、干扰效应没有显著差异(P>0.01)。结论 1)突发刺激下神经肌肉活动具有显著时间优势,且会对当前的任务造成干扰;2)突发强声刺激对机体意识反应活动的干扰效应有随刺激强度增强而增大的趋势,但神经肌肉反应的时间优势效应量以及神经肌肉反应的幅度不受刺激强度的影响。

Time Priority of Neuro-muscular Response Elicited by Unexpected Intensive Stimulus

Objective To study the time priority of the neuro-muscular response elicited by the unexpected intensive stimulus over the reaction time under consciousness and probe the changes caused by intense of the stimuli.Methods In Experiment 1,110 dB pure tone with low pitch was selected as eliciting stimulus,the time priority and the latency of the neuro-muscular response were quantified with surface electrodes of EMG.Experiment 2 examined the intense effect of the eliciting stimuli(90 dB,100 dB,110 dB) based on the result of Experiment 1.Results 1) The latency of neuro-muscular response was 382 ms,and it had a significant priority over the reaction time under consciousness,as much as 1178 ms.2) The difference of the amounts of subjects with startle reflex among three intense groups was significant(P<0.01),but the difference of latency,maximal amplitude,time advantage effect and interfering effect of neuro-muscular response were not significant(P>0.01) among 3 groups.Conclusion 1) There is significant time priority effect of neuro-muscular response elicited by unexpected intensive stimulus and it will interfere in the reaction time of current task significantly.2) Although there is an increase trend of the interference effects with the intensity increase of the eliciting stimulus,the amount of time priority and amplitude are not influenced by the intensity of the eliciting stimulus.