Acoustic measures of vigilance

Aberrant auditory processing can complicate using or acquiring a second language and, in some cases, even a first language. Determining the aberrations remains intractable. This study limits the scope of inquiries with evidence that the prolonged perceptual changes that accompany impaired vigilance need not alter an intact auditory system. A three-generation kinship with narcolepsy was tested using sets of synthetic ge-ye and i-I-e sounds. In all affected individuals, vigilance-dependent perceptual changes were pervasive, persistent, and preferentially affected sounds processed in cortex. With the youngest generation, these appeared before language acquisition was complete. The medicine methylphenidate restored vigilance and stable auditory perception. All individuals in generations II and III became proficient in at least two languages.