Language is a broad term that is used to describe our system of communicating with each other by symbols. This system has specific rules that govern the ways we use sounds, letters, and words to express ourselves. Language is a unique capability that many consider intrinsically linked to thought itself. It is often seen as a significant component of our intelligence and one of the major things that separate us from other animals.

Frequently the terms language and speech are used interchangeably, but this is incorrect. Speech is the physical process we use to express ourselves orally, but language also encompasses the whole scope of our comprehension, grammar, and written communication. Of course anything as complex as language is likely to be affected by epilepsy and other neurological disorders.

What part of my brain is responsible for language?

For nearly all right-handed people, language and verbal skills are associated with the functions of the left cerebral hemisphere. This is also primarily true for most left-handers, although a significant minority of them have language originating from the right hemisphere or from both cerebral hemispheres.

Within the cerebral hemispheres, the specific "language zones" are found in certain regions of the frontal lobe and temporal lobe, around the sylvian fissure, which forms the top border of the temporal lobe. These zones were first identified in the 19th century. In 1861, a French surgeon, Paul Broca, described a patient who was unable to express himself verbally, but could understand spoken and written speech without difficulty. After death, this patient was found to have a lesion in the lower posterior portion of his left frontal lobe, a region that continues to be labeled as Broca's area. In 1874, Karl Wernicke followed this observation with a description of a patient who was able to speak, but could not understand language. This patient's brain abnormality was found in what is now called Wernicke's area, a portion of the left posterior temporal lobe.

Are these areas the same for everybody?

We've already mentioned that some left-handed people have language centered in the right hemisphere or both hemispheres of their brain. Other exceptions to language dominance by these areas of the left frontal and temporal lobes may occur if some disorder affects them early in a child's life, while the patterns are developing. Nearby undisturbed areas of the left hemisphere may take over, or language may be transferred completely to the unaffected right hemisphere. If this happens, the child's language development may be normal, even into adulthood. In some cases, however, disorders in the development of language skills may become apparent as early as the toddler years or as late as adulthood.