Competition between brain hemispheres during sleep

Human beings are bilaterally symmetrical. As such, our brains are made of two halves called hemispheres, that communicate with each other with specialized fiber tracts running across the midline. While each hemisphere tends to deal with the senses (vision, hearing, touch) and motor control of the opposite side of the body, we are generally not aware of this partitioning of function, thanks to constant inter-hemispheric communication. In humans, the two hemispheres are also specialized for certain functions: language areas, for example, are typically in the left hemisphere.

Quelle: IDW Informationsdienst Wissenschaft