人類腦電波在不同刺激間隔時間下事件相關頻譜震盪之伴隨性負變化反應評估研究

A Study of Contingent Negative Variation Response Evaluation of Event Related Spectral Perturbation in Human Brainwaves under Different Stimulus Intervals

事件相關頻譜震盪(Event-related spectral perturbation, ERSP)是由事件相關反同步化反應(Event-related desynchronization, ERD)與事件相關同步化反應(Event-related synchronization, ERS)兩者結合，可觀察頻率隨時間變化反應與伴隨性負變化(Contingent negative variation, CNV)在不同刺激間隔長短下的反應，本研究尋找15位身心健康的成年人，年齡介於20歲至30歲(平均年齡22.5歲)，參與兩種不同時間間隔的實驗，分別為短時間刺激間隔實驗與長時間刺激間隔實驗。預備信號為喀聲(80dB)，命令信號則為閃光，而喀聲與閃光刺激間隔則因實驗內容而定。短時間刺激間隔實驗中分別為500ms、600ms、700ms、800ms、900ms和1s。長時間刺激間隔實驗中分別為2.2s、2.4s、2.5s、2.6s、2.8s和3s。實驗結果顯示在短刺激間隔實驗下ERSP會由ERS逐漸趨向ERD，而長刺激間隔實驗則只有在出現命令信號之後才會有ERD的產生，當刺激間隔的時間越長時，專注度也會隨之降低。結論顯示，當間隔時間超過3s時，受測者的ERP負向波形振幅將會出現大幅縮小甚至消失，表示當超過3s時人類腦電波反映顯示其將趨於疲乏並且注意力大幅降低，此研究結果未來可期待被應用於復健之專注力成效、過動症之專注力等臨床應用。

Event-related spectral perturbation (ERSP) is a combination of event-related desynchronization (ERD) and event-related synchronization (ERS).In order to observe time frequency responses versus the responses of contingent negative variation (CNV) under the different stimulus interval length. In this study, 15adultswhose ages were between 20 and 30 years old (average of 22.5 years old) participated in this study. Two experiments with different stimulus time intervals were designed. They are the short stimulation interval experiment and the long stimulation interval experiment. The preparatory signal is a click (80dB) and the command signal is a flash. The interval between the click and the flash stimulus is determined by the content of the experiment. In the short stimulation interval experiment, they were 500 ms, 600 ms, 700 ms, 800 ms, 900 ms, and 1s. In the long stimulation interval experiment, they were 2.2s, 2.4s, 2.5s, 2.6s, 2.8s and 3s, respectively. The experimental results show that the ERSP will gradually move from ERS to ERD in the short stimulation interval experiment, while the long stimulation interval experiment will produce ERD only after the command signal appears. Therefore, the longer stimulus interval it is, the lower attention the subject has. The conclusion shows that the interval exceeds 3s, the negative ERP waveform amplitude of the subjects will be greatly reduced or even disappear. It means that the interval exceeds 3s, the EEG will show that the subjects will tend to fatigue, and their attention will be greatly reduced. The results of this study can be expected to be applied to clinical applications such as the attention effect of rehabilitation and the focus of ADHD in the future.