Rapid automatized naming and lexical decision in children from an electrophysiological perspective.

摘要

Rapid Automatized Naming (RAN) deficits have been associated with less developed orthographic abilities that may affect lexical decisions. The effects of Spanish-speaking children's RAN performance on lexical decisions were evaluated by analyzing ERP and behavioral measures. Based upon their naming speed in four RAN tasks, 28 normal IQ, right-handed, 7-year-old children were selected and divided uniformly into two groups: average-naming (AN), and slow-naming (SN). ERPs were obtained during a lexical decision task consisting of 100 strings of four sequentially-presented letters that completed words (50 trials) or pseudowords (also 50 trials). The SN group showed major reading difficulties when compared to the AN group, as well as a significantly lower number of correct responses and slower reaction times in the lexical task. Two main ERP components were observed: parietal N320, interpreted as analogous to N170/N200; and a subsequent P3-like component (P500) with a higher amplitude for pseudowords, which probably reflects higher cognitive demands. Better reading comprehension and fewer misread pseudowords correlated with minor N320 latencies, while lower N320 amplitudes for words correlated with faster reading speeds, lower naming times and fewer errors while reading a text. The present results suggest that naming speed and ERP seem to be valuable in distinguishing early orthographic stored code retrieval abilities through a lexical decision task. Moreover, RAN and ERP emerge as accurate tools for evaluating reading processes in the early stages of reading acquisition.