Neuroimaging of Language
Neuroimaging and electrophysiology let researchers observe the brain at work during language, mapping the networks and time course of comprehension and production.
Definition
The use of electrophysiological and hemodynamic imaging methods to study the neural correlates and time course of language processing.
Scope
This topic covers event-related potentials such as the N400 and P600, hemodynamic methods such as PET and fMRI, and what they reveal about the cortical networks and temporal dynamics of language processing. It describes the methods and their findings, including their interpretive limits, rather than clinical applications.
Core questions
- Which brain networks are recruited during comprehension and production?
- What do ERP components such as the N400 and P600 index in real-time processing?
- How do spatial and temporal imaging methods complement one another?
Key concepts
- N400
- P600
- event-related potential
- fMRI
- temporal versus spatial resolution
Key theories
- ERP components and processing stages
- The use of the N400 (semantic integration) and P600 (syntactic processing and repair) to dissociate the timing of meaning- and structure-related operations.
- Network mapping from hemodynamic imaging
- Price's synthesis of two decades of PET and fMRI showing a distributed, partly bilateral network for speech, language, and reading beyond the classical regions.
History
The discovery of the N400 in 1980 and the P600 in the 1990s gave electrophysiological markers of language processing, while PET and fMRI from the 1990s onward, synthesized by Price in 2012, mapped distributed language networks.
Debates
- Localization and reverse inference
- How firmly activation in a region can be tied to a specific linguistic process, given that regions participate in many functions, and the limits of inferring function from imaging.
Key figures
- Marta Kutas
- Steven Hillyard
- Angela Friederici
- Cathy Price
Related topics
Seminal works
- kutashillyard1980
- friederici2002
- price2012
Frequently asked questions
- What does the N400 measure?
- The N400 is an event-related potential that grows larger when a word is semantically unexpected or hard to integrate, providing a sensitive index of meaning processing in real time.