Post-critical-period language learning

Optimizing post-critical-period language learning
Catherine J. Doughty
University of Maryland Center for Advanced Study of Language
In: Granena, Gisela and Mike Long (eds.), Sensitive periods, language aptitude, and ultimate L2 attainment . 2013. xv, 295 pp. (pp. 153–176)

This chapter reports on a new language aptitude test, the High-level Language Aptitude Battery (Hi-LAB), whose development was motivated by the need for an aptitude measure for more advanced L2 speakers.
Since many language learners begin as adults, critical-period constraints work against the desired outcome.
All may not be lost, however, given that some individuals attain high-level, if not native, proficiency, despite a late start.
We hypothesize that they possess language aptitude comprising inherent cognitive and perceptual abilities that compensate, at least in part, for the typical post-critical-period degradation in language-learning capacity.
While tests currently in use were designed to predict early rate of learning in instructed settings, Hi-LAB is conceptualized to predict successful ultimate attainment.
Aptitude is a measurable ceiling on language learning, holding equal all other factors.

We discuss constructs and measures, reliability and validity evidence, and uses of Hi-LAB for selecting learners for language training and in aptitude-by-treatment interaction studies.