Pauli P, Schleichert H, Bourne L E, Birbaumer N
University of Tübingen, Institute of Medical Psychology and Behavioral Neurobiology, Tübingen, Germany
Brain Res Cogn Brain Res. 1998 Jul;7(1):49-56. doi: 10.1016/s0926-6410(98)00010-x.
A biofeedback procedure was used to influence participants' cortical polarity before the presentation of single digit multiplication problems. To ensure that participants could solve the problems by direct memory retrieval of arithmetic facts, only nine different multiplication problems were used, and participants received extensive pre-experimental practice on these problems. After biofeedback training, cortical positivity before problem presentation was associated with faster response initiation times, a measure of mental calculation time, for correctly solved problems and with more multiplication errors than cortical negativity. Response execution time, a measure of motor speed, was not affected by cortical polarity. The shift in positivity from the amplitude of the slow cortical potential (SCP) before problem presentation to the amplitude of the positive slow wave (pSW) after problem presentation was less in positivity-required compared to negativity-required trials, mainly because of the manipulation of SCP starting points by biofeedback. We assume that cortical positivity is associated with direct retrieval of arithmetic facts, more precisely with the inhibition of incorrect answers. Cortical positivity before task presentation results in a reduced positive shift, a sign of less inhibition before answer production. The effect of less inhibition during positivity-required trials is to produce faster responses and more errors. The opposite might to be true of cortical negativity.
在呈现一位数乘法问题之前，采用生物反馈程序来影响参与者的皮质极性。为确保参与者能够通过直接记忆算术事实来解决问题，仅使用了九个不同的乘法问题，并且参与者在实验前对这些问题进行了大量练习。生物反馈训练后，对于正确解决的问题，问题呈现前的皮质正性与更快的反应启动时间（一种心理计算时间的度量）相关，且与更多的乘法错误相关，而皮质负性则不然。反应执行时间（一种运动速度的度量）不受皮质极性的影响。与需要皮质负性的试验相比，在需要皮质正性的试验中，从问题呈现前慢皮质电位（SCP）的幅度到问题呈现后正慢波（pSW）的幅度的正性变化较小，这主要是由于生物反馈对SCP起始点的操纵。我们假设皮质正性与算术事实的直接检索相关，更确切地说与错误答案的抑制相关。任务呈现前的皮质正性导致正性变化减小，这是答案产生前抑制较少的一个迹象。在需要皮质正性的试验中抑制较少的效果是产生更快的反应和更多的错误。皮质负性可能情况相反。
