Published online by Cambridge University Press: 28 September 2017
Pierce, Genesee, Delcenserie, and Morgan have provided an innovative and thought-provoking juxtaposition of the putative role played by phonological working memory (PWM) in explaining individual and group differences among early internationally adopted (IA) children, deaf children with cochlear implants, simultaneous and sequential bilinguals, children who are learning sign languages, and children with otitis media. This novel comparison suggests that adequate exposure to phonology before 12 months of age is key in the development of improved PWM. Consequently, long-term linguistic advantages in vocabulary and learning of morphosyntax arise, but not advantages in other areas of higher cognition. One significant implication of the review is that although many intriguing links exist between language development and PWM, irrefutable conclusions elude the field as to the directionality of a causal relationship between phonological development, other linguistic development, and PWM. In this commentary, I should like to make the somewhat controversial proposal (Gathercole, 2006, and commentaries) that the evidence presented points to PWM being an epiphenomenon arising out of individual differences in the robustness and richness of phonological representations themselves. The authors hinted several times at the tantalizing relationship between phonology and PWM, but they do not articulate explicitly that PWM could be a redundant construct. I also offer some proposals as to how one might test this suggestion experimentally or in a corpus of child language.