Maslovat Dana, Chua Romeo, Carlsen Anthony N, May Curtis, Forgaard Christopher J, Franks Ian M
School of Kinesiology, University of British Columbia, Canada; Department of Kinesiology, Langara College, Canada.
School of Kinesiology, University of British Columbia, Canada.
Acta Psychol (Amst). 2015 Jun;158:36-42. doi: 10.1016/j.actpsy.2015.04.003. Epub 2015 Apr 25.
When a startling acoustic stimulus (SAS) is presented in a simple reaction time (RT) task, response latency is significantly shortened. The present study used a SAS in a psychological refractory period (PRP) paradigm to determine if a shortened RT1 latency would be propagated to RT2. Participants performed a simple RT task with an auditory stimulus (S1) requiring a vocal response (R1), followed by a visual stimulus (S2) requiring a key-lift response (R2). The two stimuli were separated by a variable stimulus onset asynchrony (SOA), and a typical PRP effect was found. When S1 was replaced with a 124dB SAS, R1 onset was decreased by 40-50ms; however, rather than the predicted propagation of a shortened RT, significantly longer responses were found for RT2 on startle trials at short SOAs. Furthermore, the 100ms SOA condition exhibited reduced peak EMG for R2 on startle trials, as compared to non-startle trials. These results are attributed to the startling stimulus temporarily interfering with cognitive processing, delaying and altering the execution of the second response. In addition to this "startle refractory period," results also indicated that RT1 latencies were significantly lengthened for trials that immediately followed a startle trial, providing evidence for longer-term effects of the startling stimulus.
当在简单反应时（RT）任务中呈现一个令人吃惊的听觉刺激（SAS）时，反应潜伏期会显著缩短。本研究在心理不应期（PRP）范式中使用SAS，以确定缩短的RT1潜伏期是否会传递到RT2。参与者执行一项简单RT任务，其中听觉刺激（S1）需要发声反应（R1），随后是视觉刺激（S2）需要按键反应（R2）。这两个刺激由可变的刺激起始异步（SOA）隔开，并且发现了典型的PRP效应。当S1被124dB的SAS取代时，R1起始延迟减少了40 - 50毫秒；然而，在短SOA的惊吓试验中，对于RT2，并未出现缩短的RT所预测的传递现象，反而发现反应明显更长。此外，与非惊吓试验相比，在100毫秒SOA条件下，惊吓试验中R2的肌电图峰值降低。这些结果归因于惊吓刺激暂时干扰了认知加工，延迟并改变了第二个反应的执行。除了这种“惊吓不应期”外，结果还表明，在紧接着惊吓试验的试验中，RT1潜伏期显著延长，这为惊吓刺激的长期效应提供了证据。
