Sanquist T F, Beatty J T, Lindsley D B
Electroencephalogr Clin Neurophysiol. 1981 Jun;51(6):639-49. doi: 10.1016/0013-4694(81)90208-x.
The slow brain potentials observed during the 4 sec interstimulus interval (ISI) of a CNV paradigm were investigated by a factorial manipulation of the parameters that have been identified as affecting the CNV at ISIs of 1 or 2 sec. Subjects performed choice and simple reaction time (RT) tasks under all possible combinations of auditory and visual warning (S1) and imperative (S2) stimuli. The choice task involved easy or difficult intensity discriminations at S2, which were forewarned by S1s that cued the subject as to the level of difficulty for that trial. Principal components analysis (PCA) of the data revealed two negative afterwave factors and a late positive component (LPC) related to warning stimulus variables, and a late negative shift preceding S2 that was related to motor preparation. The negative afterwave components were enhanced in the choice RT task, and the earlier of the two components showed a modality-specific distribution. The LPC factor was also enhanced in the choice task and was further enhanced by S1s signaling difficult discriminations. Additionally, the LPC was larger for visual S1s. The S1-related components are interpreted in terms of orienting, while the later shift is identified with the readiness potential and motor preparation. The results support the notion that the conventionally recorded CNV consists of S1 evoked and response-related potentials rather than non-specific and modality-specific anticipatory potentials.
在CNV范式的4秒刺激间隔（ISI）期间观察到的慢脑电位，通过对已确定在1或2秒ISI时影响CNV的参数进行析因操作来进行研究。受试者在听觉和视觉警告（S1）与指令（S2）刺激的所有可能组合下执行选择和简单反应时（RT）任务。选择任务涉及在S2处进行容易或困难的强度辨别，由S1预先提示，S1向受试者提示该试验的难度水平。对数据进行主成分分析（PCA）发现了两个负后波因子和一个与警告刺激变量相关的晚期正成分（LPC），以及在S2之前与运动准备相关的晚期负向偏移。负后波成分在选择反应时任务中增强，且两个成分中较早的那个显示出模态特异性分布。LPC因子在选择任务中也增强，并且由指示困难辨别的S1进一步增强。此外，视觉S1的LPC更大。与S1相关的成分从定向角度进行解释，而较晚的偏移与准备电位和运动准备相关。结果支持这样一种观点，即传统记录的CNV由S1诱发电位和反应相关电位组成，而非非特异性和模态特异性预期电位。
