Rethinking the neurological basis of language

stowe, haverkort, zwarts

The clasical view of neurolinguistics assumed that language was localized in the left hemisphere, Broca's and Wernicke's area were the main areas involved in language, and they were only involved in language. These are incorrect.

Peterson et al. performed the first neuroimaging study of normal individuals in 1989.

In the classical view, Broca's was involved in production and Wernicke's in comprehension. Neuroimaging studies have shown that linguistic centers cannot be split up this way.

They are both necessary for normal language functioning. Both light up for semantic and syntactic tasks. Broca's area might be responsible for general working memory and storage of information. This is why Broca's aphasics have trouble with syntax and leave out function words.

It is possible that there are two functionally seperate systems in one anatomical area. Broca's area can be divided into 3 sections. It sometimes lights up when a person hears music.

The anterior temporal lobe on both the right and left sides are somehow involved in the comprehension of syntactically, lexically, or semantically ambiguous sentences.

articulatory rehearsal and error detection are utilized when the sentence is difficult or ambiguous. This lights up motor areas and the right cerebellum, which may be involved in error detection.

The superior frontal gyrus is involved in semantic evaluation.

The anterior insula is used in articulation. The "left anterior insula is important for fine motor coordination in speech."

"The posterior inferior temporal and fusiform gyrus are important for various aspects of langauge processing.

These areas are not dedicated to language, but are part of the language system.

The right frontal lobe is important for understanding metaphors, for humor comprehension, and inferring topic shifts.

The right hemisphere figures out nonliteral meanings of sentences.

"when processing demands increase, activation in the right hemisphere increases."

"Language as a complete anatomical network is not modular, relative to other cognitive functions. Component functions within the language network may be specific to language."