Mordkoff J T, Grosjean M
Department of Psychology, The Pennsylvania State University, University Park 16823, USA.
Psychophysiology. 2001 Sep;38(5):777-86.
Previous studies have found that the magnitude of the lateralized readiness potential (LRP) at the time of response initiation is constant across spontaneous variations in response time in both cued and uncued, speeded tasks. Other studies have found that the LRP is also unaffected by instructed changes in peak response force and time to peak force in cued, self-paced tasks, but that the LRP is sensitive to instructed changes in force gain rate in uncued, self-paced tasks. The present study examined the LRP in an uncued, speeded task as a function of response time and several measures of response kinetics. The magnitude of the LRP at the time of electromyographic onset was constant across spontaneous variations in all measures. The peak of the contingent negative variation did vary as a function of peak response force and integrated force to peak, but not response time. These findings support the idea that the LRP in speeded tasks is a selective, on-line index of the preparation associated with using a particular hand, and is not an index of the elements of motor programming that determine subsequent response kinetics.
以往研究发现，在有线索和无线索的快速任务中，反应启动时侧化准备电位（LRP）的幅值在反应时间的自发变化过程中保持恒定。其他研究发现，在有线索的自定步速任务中，LRP也不受指令性的峰值反应力和达到峰值力时间变化的影响，但在无线索的自定步速任务中，LRP对指令性的力增益率变化敏感。本研究在无线索的快速任务中，将LRP作为反应时间和几种反应动力学指标的函数进行了检验。在所有指标的自发变化过程中，肌电图开始时LRP的幅值保持恒定。伴随负变化的峰值确实随峰值反应力和达到峰值的积分力而变化，但不随反应时间而变化。这些发现支持了这样一种观点，即快速任务中的LRP是与使用特定手相关的准备的选择性在线指标，而不是决定后续反应动力学的运动编程要素指标。
