Information processing for motor control under non-coscious perception using ERP

本研究采用后向掩蔽范式，使用简单反应时(RT)任务进行了几个实验，考察了无知觉和运动反应的知觉潜在信息加工的本质。为了考察行为方面，我们测量了(1)在两个强迫选择任务中对首要刺激的知觉，(2)作为对命令性刺激集(首要刺激和掩蔽)的运动反应的反应时，以及(3)事件相关电位，即根据平均脑电波计算的偏侧就绪电位。实验结果表明，简单反应时与S-LRP的潜伏期(即从刺激开始到运动过程开始的时间)相关，而R-LRPs的潜伏期(即，从刺激开始到运动过程开始的时间)与R-LRPs的潜伏期(即，R-LRPs)相关。运动准备过程的处理时间)与简单的反应时间无关。这表明，主刺激比没有主刺激的条件更早地促进运动信息的加工。在掩蔽刺激被掩蔽的后向掩蔽条件下，缺乏对主要刺激知觉的觉察。除R-LRP外，S-LRP在初级掩蔽条件下的潜伏期与简单反应时相关，提示潜意识知觉初级刺激促进了运动反应，导致反应时缩短。ERPs还显示，在初级掩蔽条件下，P100出现明显，而P300没有出现，表明初级刺激在视觉信息加工的早期阶段被加工，而不是在认知阶段。这种来自屏蔽主刺激的感觉输入可能直接促进运动信息的各个阶段，绕过主刺激的显性认知信息处理阶段。

This study examined the nature of information processing underlying perception without awareness and motor responses, conducting several experiments using simple reaction time (RT) tasks with a backward masking paradigm, in which a prime and mask stimuli were presented with a short SOA. To examine behavioral aspects we measured (1) the awareness of perception of the prime stimulus in a two-forced-choice task, (2) reaction times as motor responses to the imperative stimulus set (prime and mask), and (3) Event-related potentials (ERP), lateralized readiness potentials (LRPs), which were calculated on the basis of averaged EEG waves.Results of experiments showed that simple reaction times were correlated with the latency of S-LRPs (i. e., the time from the stimulus onset to the initiation of motor processes), whereas the latency of R-LRPs (i. e., the processing time for motor preparation processes) was not correlated with simple reaction times. This suggested that the prime stimulus facilitated the stages of motor information processing earlier than conditions without prime stimulus. Awareness of perception of the prime stimulus was absent for backward masking conditions in which the prime stimulus was masked by the mask stimulus. The results that the latency of S-LRPs other than R-LRPs for the prime-masked conditions was correlated with simple reaction times suggested that non-consciously perceived prime stimulus facilitated motor responses, resulting in short reaction times. ERPs also showed that P100 appeared clearly whereas P300 did not appear for the prime-masked conditions, indicating that the prime stimulus was processed at early stages of visual information processing but not at cognitive stages. Such sensory inputs from the masked prime stimulus may facilitate directly the stages of motor information, bypassing the stages of explicit, cognitive information processing of the prime stimulus.