Maturational Constraints on Language Development

Abstract

This article reviews the second language research on age-related differences, as well as first language work needed to disambiguate some of the findings. Five conclusions are drawn, (a) Both the initial rate of acquisition and the ultimate level of attainment depend in part on the age at which learning begins, (b) There are sensitive periods governing language development, first or second, during which the acquisition of different linguistic abilities is successful and after which it is irregular and incomplete, (c) The age-related loss in ability is cumulative (not a catastrophic one-time event), affecting first one linguistic domain and then another, and is not limited to phonology, (d) The deterioration in some individuals begins as early as age 6-not at puberty as is often claimed, (e) Affective, input, and current cognitive explanations for the reduced ability are inadequate. The capacity for language development is maturationally constrained, and its decline probably reflects a progressive loss of neural plasticity, itself possibly associated with increasing myelination.

Judgments of information structure in L2 French: Nativelike performance and the Critical Period Hypothesis

“…This violates Johnson & Newport's (1989) criterion that late-AoA learners should not exhibit native-like behavior, as well as Singleton & Ryan's (2004) criterion that learners cannot acquire a target behavior once a critical period has passed. In this experiment, the high degree of nativelikeness may not be suitable evidence for rejection as the judgment task may have been too easy for many of the respondents (see Long 1990). Relatedly, we must take into account the possibility of transfer between English as an L1 and French as an L2 as far as information structure is concerned.…”

The loss of first language phonetic perception in adopted Koreans

“…Flege et al, 1995;Weber-Fox & Neville, 1996;Pallier, Bosch & Sebastian, 1997). According to some authors, there is a progressive decline in the ability to learn a language which can be noticed when exposure starts after age six (Long 1990;Pinker, 1994;but see Birdsong, 1999). If cortical networks subserving language processing become progressively crystallized during the first ten years of life, then it is plausible that early exposure to a language should leave permanent traces in those networks.…”

A limit on behavioral plasticity in speech perception

“…For example, a 40-year-old immigrant who has spent the last 20 years in the US is more likely to speak with a strong accent than is an 8 year-old child who has lived in the US for 2 years. More precisely, most studies have shown that a non-native accent can be detected when the age of acquisition was above 6 years (for a comprehensive review, see Long, 1990). In a recent study, the foreign accent of 240 Italians immigrants was rated by native English listeners: the mean ratings decreased gradually with the age of arrival, and the most discerning listener could already detect an accent in the subgroup of Italians who had arrived before 4 years of age (Flege et al, 1995).…”