Nakata Hiroki, Inui Koji, Wasaka Toshiaki, Tamura Yohei, Kida Tetsuo, Kakigi Ryusuke
Department of Integrative Physiology, National Institute for Physiological Sciences, Myodaiji, 444-8585, Okazaki, Japan.
Exp Brain Res. 2005 Apr;162(3):293-9. doi: 10.1007/s00221-004-2195-4. Epub 2004 Dec 15.
The present study investigated the characteristics of the middle-latency negative potential of event-related potentials (ERPs) using somatosensory go/nogo tasks. We manipulated interstimulus interval (ISI) in Experiment 1 and stimulus probability in Experiment 2 and analyzed the subtracted difference waveform resulting from subtraction of the ERP evoked by the go stimulation from that evoked by the nogo stimulation. In Experiment 1, the peak latency of negativity became significantly longer as the ISI increased, but the peak amplitude was unchanged. The reaction time (RT) was longer with increasing ISI. In Experiment 2, manipulation of the stimulus probability yielded an increase in peak amplitude with decreasing probability of the nogo stimulus, but did not affect the latency. The RT increased as the probability of a nogo stimulus rose. Because manipulation of the ISI and stimulus probability elicited different brain activities, we hypothesized that manipulation of the ISI elicited a delay of the stimulus evaluation process including response inhibition, and that stimulus probability significantly affected the strength of the response inhibition process.
本研究使用体感去/不去任务，调查了事件相关电位（ERP）中潜伏期负电位的特征。在实验1中，我们操纵了刺激间隔（ISI），在实验2中操纵了刺激概率，并分析了不去刺激诱发的ERP减去去刺激诱发的ERP后得到的差值波形。在实验1中，随着ISI增加，负电位的峰值潜伏期显著延长，但峰值幅度不变。反应时间（RT）随着ISI增加而延长。在实验2中，操纵刺激概率导致随着不去刺激概率降低，峰值幅度增加，但不影响潜伏期。随着不去刺激概率上升，RT增加。由于操纵ISI和刺激概率引发了不同的大脑活动，我们推测，操纵ISI引发了包括反应抑制在内的刺激评估过程的延迟，并且刺激概率显著影响反应抑制过程的强度。
