Study of ERP during implementation of discrimination response task under painful electric stimuli applied to the second branch of trigeminal nerve

• Published in: Japanese Journal of Oral and Maxillofacial Surgery Vol. 36; no. 1; pp. 37 - 49
• Main Author: LAI, Jen Li
• Format: Journal Article
• Language: English
• Published: Japanese Society of Oral and Maxillofacial Surgeons 1990
• Subjects: event related potentials; P 300; trigeminal nerve
• ISSN: 0021-5163; 2186-1579
• DOI: 10.5794/jjoms.36.37

The author attempted to elucidate the sensory recognition process in the oral and maxillofacial area through ERP during implementation of a 100% random stimulation, rightleft discriminatory response task and a strength discriminatory response task by using a painful electric stimulus applied on the upper lip. As a result, the following conclusions were obtained: 1. Irrespective of the strength of the stimulus and the nature of the task, five common major components consisting of N 65, p100, N 140, P 300 and N 400 were noted. 2. An ERP in the implementation of a discriminatory response task of painful stimulus revealed the presence of a positive component at 250 msec through 350 msec not only in the target stimulus input but also in the regular stimulus input, thereby showing a characteristic different from that ensuring a non-invasive stimulus. It was suggested that the current P 300 ensuring a painful stimulus reflects not only the renewal of recognition content appearing independent of the mode of stimulus as does conventional P 300 but also the evaluation of the situation including recognition of pain and empirical check of the past events. 3. The reaction time in the implementation of each task was proportional to the degree of difficulty of the task, and tended to be prolonged by a multiple of the radix of 60 msec. 4. p100 and N 140 represented electric potential changes occurring in the disposal process of selective attention, and were components corresponding to stimulus-set attention. Furthermore, they seemed to be components corresponding to response-set attention differentiating the target stimulus between N 2 and P 300, checking and differentiating OR from intrinsic memory, evaluating the task relevance and making a decision of the task to be carried out. The intrinsic positive component near 700 msec noted in the waveform, obtained by subtracting the reference stimulus input ERP from the target stimulus input ERP during the strength discriminating task seemed to be a component corresponding to perceptomotor sequelae to reconfirm a response after implementation of the task.