We employed a visual rhyming priming paradigm to characterize the development of brain systems important for phonological processing in reading. We studied 109 righthanded, native English speakers within eight age groups: 7-8, 9-10, 11-12, 13-14, 15-16, 17-18, 19-20, and 21-23. Participants decided whether two written words (prime-target) rhymed (JUICE-MOOSE) or not (CHAIR-MOOSE). In similar studies of adults, two main event-related potential (ERP) effects have been described: a negative slow wave to primes, larger over anterior regions of the left hemisphere and hypothesized to index rehearsal of the primes, and a negative deflection to targets, peaking at 400-450 msec, maximal over right temporal-parietal regions, larger for nonrhyming than rhyming targets, and hypothesized index phonological matching. In this study, these two ERP effects were observed in all age groups; however, the two effects showed different developmental timecourses. On the one hand, the frontal asymmetry to primes increased with age; moreover, this asymmetry was correlated with reading and spelling scores, even after controlling for age. On the other hand, the distribution and onset of the more posterior rhyming effect (RE) were stable across age groups, suggesting that phonological matching relied on similar neural systems across these ages. Behaviorally, both reaction times and accuracy improved with age. These results suggest that different aspects of phonological processing rely on different neural systems that have different to developmental timecourses.

In a simple auditory rhyming paradigm requiring a button-press response (rhyme/nonrhyme) to the second word (target) of each spoken stimulus pair, both the early (P50, N120, P200, N240) and late (CNV, N400, P300) components of the ERP waveform evidenced considerable change from middle childhood to adulthood. In addition, behavioral accuracy and reaction time improved with increasing age. In contrast, the size, distribution and latency of each of several rhyming effects (including the posterior N400 rhyming effect, a left hemisphere anterior rhyming effect, and early rhyming effects on P50 latency, N120 latency and P200 amplitude) remained constant from age 7 to adulthood. These results indicate that the neurocognitive networks involved in processing auditory rhyme information, as indexed by the present task, are well established and have an adult-like organization at least by the age of 7.

Abstract& Awareness of change within a visual scene only occurs in the presence of focused attention. When two versions of a complex scene are presented in alternating sequence separated by a blank mask, unattended changes usually remain undetected, although they may be represented implicitly. To test whether awareness of change and focused attention had the same or separable neurophysiological substrates, and to search for the neural substrates of implicit representation of change, we recorded event-related brain potentials (ERPs) during a change blindness task. Relative to active search, focusing attention in the absence of a change enhanced an ERP component over

Studies of written and spoken language suggest that nonidentical brain networks support semantic and syntactic processing. Eventrelated brain potential (ERP) studies of spoken and written languages show that semantic anomalies elicit a posterior bilateral N400, whereas syntactic anomalies elicit a left anterior negativity, followed by a broadly distributed late positivity. The present study assessed whether these ERP indicators index the activity of language systems specific for the processing of aural-oral language or if they index neural systems underlying any natural language, including sign language. The syntax of a signed language is mediated through space. Thus the question arises of whether the comprehension of a signed language requires neural systems specific for this kind of code. Deaf native users of American Sign Language (ASL) were presented signed sentences that were either correct or that contained either a semantic or a syntactic error (1 of 2 types of verb agreement errors). ASL sentences were presented at the natural rate of signing, while the electroencephalogram was recorded. As predicted on the basis of earlier studies, an N400 was elicited by semantic violations. In addition, signed syntactic violations elicited an early frontal negativity and a later posterior positivity. Crucially, the distribution of the anterior negativity varied as a function of the type of syntactic violation, suggesting a unique involvement of spatial processing in signed syntax. Together, these findings suggest that biological constraints and experience shape the development of neural systems important for language.electrophysiology ͉ sign language ͉ syntax S igned languages, such as American Sign Language (ASL), are fully developed, natural languages containing all of the linguistic components of spoken languages, but they are conveyed and perceived in a completely different form than those used for aural-oral languages. (Aural-oral is used here to refer to both written and spoken language forms.) Thus, investigations of signed language processing provide a unique opportunity for determining the neural substrates of natural human language irrespective of language form. The present study used eventrelated brain potentials (ERPs) to examine semantic and syntactic processing of ASL sentences in deaf native signers of ASL and compared these findings to those from previous studies of aural-oral language.Lesion and neuroimaging studies suggest that remarkably similar neural systems underlie signed and spoken language comprehension and production. The studies illustrate the importance of a left frontotemporal network for language processing irrespective of the modality through which language is perceived. In particular, neuroimaging studies of sentence processing using written (e.g., refs. 1 and 2), spoken (e.g., refs. 3-5), and audiovisual (6, 7) stimuli have shown reliable left hemisphere-dominant activation in regions such as the inferior frontal gyrus and the posterior superior temporal cortex in hearing users of spok...

In a simple prime-target auditory rhyming event-related potential (ERP) paradigm with adults and 6-, 7-, and 8-year-old children, nonword stimuli (e.g., nin-rin, ked-voo) were used to investigate neurocognitive systems involved in rhyming and their development across the early school years. Even absent semantic content, the typical CNV to primes and late rhyming effect (RE) to targets were evident in all age groups. The RE consisted of a more negative response to nonrhyming targets as compared to rhyming targets over posterior sites, with a reversal of this pattern at lateral anterior sites. The hypothesis that the CNV indexes phonological memory processes was not well supported by correlation analyses conducted with the ERP measures and scores on standardized behavioral tests. However, the onset of the rhyming effect was later in those scoring lower on phonological awareness measures.