Event-related brain potential markers of high-language proficiency in adults.

The central issue addressed is whether there are electrophysiological markers for high-language proficiency in adults. Event-related brain potentials (ERPs) were recorded in 19 young adults who demonstrated either "normal" or "high" language proficiency. ERPs were obtained during a sentence-processing task and analyzed for specific response components elicited by different word types. The ERPs in the normal and high-language proficiency groups were similar for early sensory related processing but differed in the later components thought to be more closely related to lexical access and post-lexical processing. The findings for the ERP waveforms suggest that adults with high-language proficiency show slightly faster lexical access over left anterior brain regions for closed class items, and a reduced reliance on contextual information contained in sentences.