研究:电流刺激大脑可增强学习能力

Electrically stimulating the brain can help to speed up the process of learning, scientists have shown。

Applying a small current to specific parts of the brain can increase its activity, making learning easier。

Researchers from the University of Oxford have studied the changing structure of the brain in stroke patients and in healthy adults。

Prof Heidi Johansen-Berg presented their findings at the British Science Festival in Bradford。

The team at Oxford has been conducting research into how the structure of the brain changes in adulthood, and in particular what changes occur after a stroke。

They have used an approach called functional MRI to monitor activity in the brain as stroke patients re-learn motor skills that were lost as a result of their illness。

One of the major findings is that the brain is very flexible and can restructure itself, growing new connections and reassigning tasks to different areas, when damage occurs or a specific task is practised。

As part of this research, they investigated the possibility of using non-invasive electric brain stimulation to improve the recovery of these motor skills; the short-term improvement in stroke patients had already been noted。

But an unexpected result was found when the same brain stimulation was applied to healthy adults: their speed of learning was also significantly increased。

To observe this effect, the team devised an experiment whereby volunteers memorised a sequence of buttons to press "like playing a tune on a piano"。

While they were doing this, they were fitted with a "trans-cranial current stimulation" device, in which two electrodes are placed in a specific position on the head。

A very small current was passed between the electrodes in an arc through the brain and, depending on the direction of that current, either increased or decreased the activity of that part of the brain。

Prof Johansen-Berg explained that "an increase in activity of the brain cells makes them more susceptible to the kinds of changes that occur during learning"。

The results of the button-pressing experiments showed the positive effects of just 10 minutes of the brain stimulation on learning。

"While the stimulation didn't improve the participant's best performance, the speed at which they reached their best was significantly increased." said Prof Johansen-Berg。

In the treatment of stroke patients, the technique could be used in parallel with current physiotherapy treatments to improve overall outcomes, which tend to vary widely。

据英国广播公司9月20日报道，近期科学家研究指出，电流刺激大脑能够加速认知学习的过程。

用较小的电流刺激大脑的特定部位，可使该部位更加活跃，学习更轻松。

来自牛津大学的研究者研究了中风病人与健康成人大脑结构的变化。

在布拉德福德举办的英国科学节上，海蒂·约翰森伯格教授介绍了他们这一研究结果。

牛津研究小组一直在研究成年后大脑的结构变化，特别是中风后又发生了怎样的变化。

中风患者因为疾病原因已经忘记了原有运动技能。研究者们使用功能性磁核共振成像的方法，监测了他们重新学习该技能时的大脑活动。

主要发现之一是，其大脑非常灵活并可以自行调整脑结构，在遇到损毁或特殊任务时能产生、新的连接，并重新分配了不同脑部位的任务。

作为这项研究的一部分，他们调查了使用非侵入性的电流对脑部刺激以改善其运动技能的恢复的可能性，中风患者中有短期改善已被标记。

一个意想不到的结果是，健康的成年人受到相同的大脑刺激时，他们的学习速度也显著增加。

为了观察这种效果，研究者们设计了一个实验，让志愿被试者像在钢琴上演奏曲子一样来按一串按钮。

当他们这样做，他们实际上按住了“跨颅电流刺激”的装置，它的两个电极放置在顶端的特定位置。

电极之间传递的小股电流呈弧状通过大脑，电流的方向即可增加或减少的那部分大脑的活动。

约翰森伯格教授解释说，“增加脑细胞的活动使大脑更易受学习过程发生的变化的影响”。

按钮实验结果显示，仅10分钟的脑刺激即可对学习产生的积极影响。

“虽然刺激没能使参与者的表现提高到最佳，但达到他们最佳表现的速度显著增加。”约翰森伯格教授说。

在对中风患者的治疗中，该技术可以与目前的物理疗法并行来明显提高整体疗效。