According to psychological research, attention switching and interference effects will occur when human beings are multitasking. When we do two tasks that need attention at the same time, our attention will switch back and forth between the two tasks, which will lead to lower efficiency. This kind of interference will make it difficult for us to concentrate on poetry recitation, thus affecting memory and understanding.
In addition, different brain regions are required for different tasks. Poetry recitation mainly involves language and memory processing, while grasping a ruler involves motion control. The brain regions required by the two tasks do not completely overlap, and there may be resource competition when the two tasks are carried out at the same time, which may lead to the inhibition of the execution of one of the tasks.
To sum up, grasping a ruler while reciting poems may lead to distraction, impaired memory and reduced efficiency in task execution. Therefore, in order to better concentrate and improve the learning effect, it is suggested to carry out each task separately and concentrate on it.