Wohlert A B
Division of Speech and Hearing Science, Ohio State University, Columbus.
J Speech Hear Res. 1993 Oct;36(5):897-905. doi: 10.1044/jshr.3605.897.
Cortical preparation for movement is reflected in the readiness potential (RP) waveform preceding voluntary limb movements. In the case of oral movements, the RP may be affected by the complexity or linguistic nature of the tasks. In this experiment, EEG potentials before a nonspeech task (lip pursing), a speech-like task (lip rounding), and single word production were recorded from scalp electrodes placed at the cranial vertex (Cz) and over the left and right motor strips (C3' and C4'). Seven right-handed female subjects produced at least 70 repetitions of the three tasks, in each of five repeated sessions. EEG records were averaged with respect to EMG onset at the lip. The word task, as opposed to the other tasks, was associated with greater negative amplitude in the RP waveform at the vertex site. Differences between the waveforms recorded at the right- and left-hemisphere sites were insignificant. Although intersubject variability was high, individuals had relatively stable patterns of response across sessions. Results suggest that the RP recorded at the vertex site is sensitive to changes in task complexity. The RP did not reflect lateralized activity indicative of hemispheric dominance.
运动的皮层准备在自愿肢体运动之前的准备电位（RP）波形中得以体现。就口腔运动而言，RP可能会受到任务的复杂性或语言性质的影响。在本实验中，从置于头顶（Cz）以及左右运动区（C3'和C4'）的头皮电极记录了非言语任务（噘嘴）、类似言语任务（圆唇）和单个单词产出之前的脑电电位。七名右利手女性受试者在五个重复的实验环节中，对这三项任务各自至少重复进行了70次。脑电记录以唇部肌电图起始点为参照进行平均。与其他任务相比，单词任务在头顶部位的RP波形中呈现出更大的负向波幅。在右半球和左半球部位记录的波形之间差异不显著。尽管个体间差异很大，但个体在各实验环节中的反应模式相对稳定。结果表明，在头顶部位记录的RP对任务复杂性的变化敏感。RP并未反映出指示半球优势的偏侧化活动。
