Rethinking bilingual language assessment: Considering implicit language acquisition mechanisms by means of pupillometry

Abstract

In this methodological paper, a tool is introduced to the field of bilingual language assessment that has been used widely in other research domains, but has never been applied to the practice of language assessment: The investigation of pupillometric reactions to grammatical violations. The pupillometry approach presented here intends to identify bilingual children at risk for developmental language disorders (DLD) as early as their onset of acquisition of their second language (L2), namely within the first few months of their kindergarten attendance. It focuses the implicit language acquisition mechanisms and the ability to derive linguistic patterns out of a string of input, an ability that is said to be impaired in children with DLD. The approach combines concepts of dynamic and static assessment, and the target structure is an early clinical marker (subject verb agreement, SVA). A SVA-structure is repeatedly presented auditorily within grammatical stimuli in a familiarization phase, followed by a test phase including grammatical and ungrammatical stimuli. During this task, the children's changes in pupil diameters are monitored. It is hypothesized that children whose language processing mechanisms are intact may react to ungrammatical stimuli encountered in their input with surprise – a sign of a violation of their expectations. Therefore, different pupil reactions to grammatical and ungrammatical stimuli after only short exposure are supposed to represent intact language processing mechanisms, whereas similar pupil reactions to grammatical and ungrammatical stimuli are supposed to indicate a risk for DLD. By means of pupillometric observations, an identification of children at risk would be possible at the beginning of L2 acquisition.