Glenn T. McCain
Brain Lateralization and Language Reflection
PSY/340


Brain Lateralization is a complex and ongoing process by which differing regions of the brain "take over" the functioning of specific behaviors and cognitive skills. Lateralization literally means that certain functions are located (in part or total) on one side of the brain.

Functions related to the right hemisphere include judging the position of objects in space, understanding of body position, comprehending and remembering things you do and see, putting pieces of information together to make an entire picture, and motor control of the left side of the body.

Functions related to the left side of the brain include understanding and use of language (listening, reading, speaking and writing), memory for spoken and written language, analysis of information in detail, and motor control of the right side of the body. These skills develop naturally over time in children and deficits in several related areas of functioning could suggest problems with this process.
Delays in lateralization can affect many cognitive and behavioral skills. Brain lateralization is critical to the development of appropriate language and social skills. Difficulties with left hemisphere development can include language deficits (including grammar, vocabulary, and literal meaning of language) or may present itself as difficulty with receptive, expressive language or articulation/fluency deficits.

Deficits in right hemisphere language development can lead to difficulties processing nonliteral language, sarcasm, metaphors and reading. Nonverbal social abilities also tend to be affected by brain lateralization. Specifically, the right hemisphere subsumes the processing of pragmatic language, prosody, and intonation as well as the ability to read facial cues, body language and to adapt behavior based on these cues. This could mean that children with difficulties secondary to lateralization of these inputs may present with difficulties reading social meaning in other children.
Individuals with Broca\'s aphasia have damage to the frontal lobe of the brain. These individuals frequently speak in short, meaningful phrases that are produced with great effort. Broca\'s aphasia is thus characterized as a nonfluent aphasia. Affected people often omit small words such as "is," "and," and "the." For example, a person with Broca\'s aphasia may say, "Walk dog" meaning, "I will take the dog for a walk." The same sentence could also mean "You take the dog for a walk," or "The dog walked out of the yard," depending on the circumstances. Individuals with Broca\'s aphasia are able to understand the speech of others to varying degrees. Because of this, they are often aware of their difficulties and can become easily frustrated by their speaking problems. Individuals with Broca\'s aphasia often have right-sided weakness or paralysis of the arm and leg because the frontal lobe is also important for body movement.