These in turn are integrated to form a complex, multimodal awareness of the entire environment. At still higher levels of cortical organization, in the association cortex, complex patterns of thought and language are possible. Lateralization Most sensory information crosses over from one side of the body to the opposite side of the brain. Likewise the entire right visual and somatosensory fields, and most of our right-sided auditory information cross over to the left side of the brain. Only the very short branches of some of the cranial nerves do not cross to the opposite hemisphere.
Lateralization is also apparent on the cellular and chemical level.
The right hemisphere tends to be more globally organized, with fewer discrete areas of functioning, and it differentially uses certain types of neurochemistry. These differences have also allowed the brain to lateralize certain cognitive and perceptual functions to the side that can best handle the task. It is important to note that essentially NO cognitive task occurs only on one side of the brain. This is a crucial piece of information, when considering how to approach the rehabilitation or compensation of a skill after brain injury. The hierarchical layering of cortical neurons is an example of localization on a cellular level, and the lateralization of brain functions is an example of localization on a larger scale.