Rockstroh B, Elbert T, Birbaumer N, Lutzenberger W
Department of Clinical and Physiological Psychology, Eberhard-Karls-Universität, Tübingen, F.R.G.
Int J Psychophysiol. 1990 Sep;9(2):151-65. doi: 10.1016/0167-8760(90)90069-p.
Two studies served to examine behavioural effects of slow cortical potentials (SPs). SPs were manipulated by means of a biofeedback procedure. The ability of human subjects to alter SPs differentially between the two hemispheres--specifically over the lateral aspects of the central sulcus--was tested by providing feedback of the SP difference between C3 and C4. In Expt. I, 21 of the 45 subjects produced hemispheric asymmetries of more than 2 microV between C3 and C4 on an average after 80 trials of analogue, continuous and immediate feedback. In Expt. II, SP changes were fed back digitally at the end of each trial. Within 120 trials, 20 of the 48 subjects reached the criterion of a minimum 2-microV difference in SPs between C3 and C4 on the average. Average differentiation remained significantly below the SP differentiations achieved for continuous feedback. Trials with feedback were followed by 'task' trials without feedback, during which subjects were still requested to produce SP changes but also had to complete a task: Either sensorimotor tasks (Expt. I) or forced choice handedness tasks (Expt. II) were presented to evaluate behavioural consequences of hemispheric SP differences. In subjects achieving the required SP differentiation it affected the behavioural output in agreement with the known functions of the respective cortical area.
两项研究旨在检验慢皮层电位（SPs）的行为效应。通过生物反馈程序对SPs进行调控。通过提供C3和C4之间SP差异的反馈，测试人类受试者在两个半球之间——特别是中央沟外侧区域——差异性改变SPs的能力。在实验I中，45名受试者中有21名在进行80次模拟、连续且即时反馈的试验后，C3和C4之间平均产生了超过2微伏的半球不对称性。在实验II中，每次试验结束时以数字方式反馈SP变化。在120次试验内，48名受试者中有20名平均达到了C3和C4之间SP差异至少为2微伏的标准。平均分化程度仍显著低于连续反馈所达到的SP分化程度。有反馈的试验之后是无反馈的“任务”试验，在此期间，受试者仍被要求产生SP变化，但还必须完成一项任务：呈现感觉运动任务（实验I）或强制选择利手任务（实验II），以评估半球SP差异的行为后果。在实现所需SP分化的受试者中，这会影响行为输出，且与相应皮层区域的已知功能相符。
