Development of a Stimulator for Elicitation of Auditory Evoked Potentials by Japanese Words.

开发了一种用日语词表达听觉诱发电位的听觉刺激器。这个刺激器随机产生两个不同频率的音调爆发和两个不同的单词。研究人员选择了几对第一个音相同而另一个音不同的日语单词进行刺激。最终选出以下6对：“A-ka, A-o”；“A-shi我”;“iυ,我”;“Ku-ma Ku-tsu”;“哈-娜，哈-托”和“萨-茹，萨-拉”。然而，以元音为首音的发音则有明显的区别，而以辅音，特别是摩擦音为首音的发音，如“Sa-ru”；“Sa-ra”被模糊区分。这很可能是由于模拟到数字转换的机器对摩擦音不太敏感。对于P300的激发，一次音调爆发的频率为20%，另一次则为80%。以低频声脉冲作为目标刺激。对每个单词给予20%和80%的声音刺激。P300由连接耳垂的顶点推导而来。P300可以被成对的日语单词“A-ka，意思是红色”和“A-o，意思是蓝色”的声音刺激以及音调爆发刺激所激发。在一个4岁的男孩身上，音调的爆发不能诱发P300，但声音的刺激可以。实验证明，该设备对P300的激发是有用的，即使在P300不能被音调爆发唤起的儿童中也是如此。声音刺激的P300潜伏期比音调刺激的P300潜伏期长。这种差异可能与第二个音区分两个单词的时间延迟有关。按按钮任务的反应时间对单词辨别的反应时间比音调辨别的反应时间要晚。

An auditory stimulater using Japanese words for auditory evoked potentials was developed. This stimulator generates two tone bursts of different frequencies, and two different words at random. Several pairs of Japanese words whose first sound was the same and the other was different were chosen for the stimulation. Finally the following 6 pairs were selected: "A-ka, A-o"; "A-shi, A-me"; "I-nu, I-su"; "Ku-ma, Ku-tsu"; "Ha-na, Ha-to" and "Sa-ru, Sa-ra". those which had a vowel as the first sound were clearly differentiated, however, those which had a consonant, especially fricative sound as the first sound such as "Sa-ru; Sa-ra" were equivocally differentiated. It is likely due to the analog to digital conversion of the machine was less sensitive to the fricative sound.For the elicitation of P300, one tone burst was given at 20% and the other was given at 80%. The tone burst which was given at low frequency was used as the target stimulation. The sound stimulation was also given at 20 and 80% for each word. P300 was derived form the vertex referred to the linked ear lobes.The P300 could be elicited by this sound stimulation of paired Japanese words of "A-ka which means red" and "A-o which means blue" as well as by the tone burst stimulation. In a 4-year-old boy, the tone bursts could not elicit P300, but the sound stimulation could. It is proved that this equipment is useful for elicitation of P300 even in children whose P300 cannot be evoked by tone burst. The latency of P300 was longer by sound stimulation than by tone burst. This difference probably relate to time delay of discrimination of the two words by the second sound.The response time evaluated by button press task was also delayed for the word discrimination than for the tone discrimination.