Paes Flávia, Machado Sergio, Arias-Carrión Oscar, Domingues Clayton Amaral, Teixeira Silmar, Velasques Bruna, Cunha Marlo, Minc Daniel, Basile Luis Fh, Budde Henning, Cagy Mauricio, Piedade Roberto, Kerick Scott, Menéndez-González Manuel, Skaper Stephen D, Norwood Braxton A, Ribeiro Pedro, Nardi Antonio Egídio
Panic and Respiration Laboratory, Institute of Psychiatry, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
Int Arch Med. 2011 Feb 4;4(1):6. doi: 10.1186/1755-7682-4-6.
The present study examined absolute alpha power using quantitative electroencephalogram (qEEG) in bilateral temporal and parietal cortices in novice soldiers under the influence of methylphenidate (MPH) during the preparatory aiming period in a practical pistol-shooting task. We anticipated higher bi-hemispheric cortical activation in the preparatory period relative to pre-shot baseline in the methylphenidate group when compared with the control group because methylphenidate has been shown to enhance task-related cognitive functions.
Twenty healthy, novice soldiers were equally distributed in control (CG; n = 10) and MPH groups 10 mg (MG; n = 10) using a randomized, double blind design. Subjects performed a pistol-shooting task while electroencephalographic activity was acquired.
We found main effects for group and practice blocks on behavioral measures, and interactions between group and phases on electroencephalographic measures for the electrodes T3, T4, P3 and P4. Regarding the behavioral measures, the MPH group demonstrated significantly poorer in shooting performance when compared with the control and, in addition, significant increases in the scores over practice blocks were found on both groups. In addition, regarding the electroencephalographic data, we observed a significant increase in alpha power over practice blocks, but alpha power was significantly lower for the MPH group when compared with the placebo group. Moreover, we observed a significant decrease in alpha power in electrodes T4 and P4 during PTM.
Although we found no correlation between behavioral and EEG data, our findings show that MPH did not prevent the learning of the task in healthy subjects. However, during the practice blocks (PBs) it also did not favor the performance when compared with control group performance. It seems that the CNS effects of MPH demanded an initial readjustment period of integrated operations relative to the sensorimotor system. In other words, MPH seems to provoke a period of initial instability due to a possible modulation in neural activity, which can be explained by lower levels of alpha power (i.e., higher cortical activity). However, after the end of the PB1 a new stabilization was established in neural circuits, due to repetition of the task, resulting higher cortical activity during the task. In conclusion, MPH group performance was not initially superior to that of the control group, but eventually exceeded it, albeit without achieving statistical significance.
本研究使用定量脑电图（qEEG）检测了新手士兵在实弹手枪射击任务准备瞄准阶段受哌甲酯（MPH）影响时双侧颞叶和顶叶皮质的绝对α波功率。我们预计，与对照组相比，哌甲酯组在准备阶段相对于射击前基线的双侧半球皮质激活会更高，因为哌甲酯已被证明可增强与任务相关的认知功能。
采用随机双盲设计，将20名健康新手士兵平均分为对照组（CG；n = 10）和10毫克MPH组（MG；n = 10）。受试者在进行手枪射击任务时记录脑电图活动。
我们发现组和练习块对行为指标有主效应，电极T3、T4、P3和P4的脑电图指标在组和阶段之间存在交互作用。关于行为指标，与对照组相比，MPH组的射击表现明显较差，此外，两组在练习块中的得分均显著增加。此外，关于脑电图数据，我们观察到练习块期间α波功率显著增加，但与安慰剂组相比，MPH组的α波功率显著较低。此外，我们观察到在预触发运动（PTM）期间电极T4和P4的α波功率显著降低。
虽然我们未发现行为数据与脑电图数据之间存在相关性，但我们的研究结果表明，MPH并未妨碍健康受试者学习任务。然而，在练习块（PBs）期间，与对照组表现相比，它也未对表现产生促进作用。似乎MPH对中枢神经系统的影响需要相对于感觉运动系统的综合操作有一个初始调整期。换句话说，MPH似乎由于神经活动的可能调节而引发了一段初始不稳定期，这可以通过较低水平的α波功率（即较高的皮质活动）来解释。然而，在PB1结束后，由于任务的重复，神经回路建立了新的稳定性，导致任务期间皮质活动更高。总之，MPH组的表现最初并不优于对照组，但最终超过了对照组，尽管未达到统计学显著性。
