Definition

The theory of localization in the brain states that specific parts of the brain control specific aspects of brain function.

Current Knowledge

Localization of function in the brain refers to the theory that specific parts of the brain control specific aspects of brain function. The idea of a localization of function in the brain has been considered for hundreds of years. The now-debunked pseudoscience of phrenology was based on the idea that brain function was localized to specific parts of the brain and a phrenologist could analyze a person’s specific brain function by examining the shape of the skull. Modern understanding of the brain is much more sophisticated, yet it is known that some brain functions are indeed localized.

The scientific community began accepting theories of localization when researchers Paul Broca, Carl Wernicke, and others discovered that damage to a specific part of the brain was associated with loss of specific functions. Paul Broca’s research showed that damage to a specific part of the brain (the left frontal lobe) was associated with speech impairment. In the 1870s, Carl Wernicke found that a specific part of the brain (upper posterior temporal lobe) was responsible for speech reception. In 1870, Gustav Fritsch and J. L. Hitzig discovered the motor cortex when they found stimulating different parts of the cortex resulted in movement in certain body parts.

Today, many brain locations have been identified to have specific functions. In addition to the speech and motor areas already outlined, Table 1 outlines some specific brain structures that have specific functions.

Localization, Table 1 Functions of specific brain structures
Full size table

While it is widely accepted that localization of function is present in the brain, the extent of interconnectivity of these areas is not completely understood.

Cross-References