Examining Featural Underspecification of "TONGUE HEIGHT" in German Mid Vowels : an EEG Study

Abstract

The present study was originally designed as a crosslinguistic investigation of asymmetries in phonological feature representations. The theoretical background of the hypotheses was the Featurally Underspecified Lexicon Model by Lahiri and Reetz (2002). This model assumes that words are stored in an abstract way, in terms of phonological features. Features that can be extracted from the speech signal, but are redundant or prone to variation within the language are not stored, resulting in underspecified lexical entries. Based on this model it was hypothesised that the vowel [e] differs in its phonological representation of TONGUE HEIGHT between Turkish and German in that it is represented as [LOW] in Turkish and underspecified for this feature in German. This hypothesis was set to test in a cross modal fragment priming study, in which subjects listen to spoken word onset fragments and are asked to decide whether an immediately following visually presented letter string is a word or not. Three conditions were included: Identical (prime fragment is first syllable of target item), related (prime fragment differs from target in nucleus of first syllable) and unrelated (prime fragment does not share segments with first syllable of target). The crucial condition was the related one. Fragments with an [e] as nucleus were expected to prime target words with an [i] at the respective position in both languages. Contrary, a prime fragment with [i] was expected to prime a corresponding target word with [e] in German but not in Turkish because the feature [HIGH] extracted from the [i] in the signal should mismatch with the feature [LOW] in the Turkish representation of [e]. The data presented here are restricted to German. Reaction times and error rates did not confirm the predictions. Only identical prime fragments eased lexical decisions to target words whereas the related condition did not differ from the unrelated control condition. An event related brain potential component known as the P350 was used as a neurophysiological index of lexical activation of target words. Mean amplitudes did not differ between the identical and related conditions whereas they both differed from the unrelated control condition. No difference in the P350 effect has been found for target words with [e] as compared to [i]. These results are in line with the predictions. The identical as well as the related condition lead to priming.