Linguistics Fridays Colloquium Talk - Wedel & Ussishkin
Signal evolution within the word
Andy Wedel, University of Arizona
Languages have been shown to optimize their lexicons over time with respect to amount of signal allocated to words: words that are on average less predictable in context tend to have more segments. But not all segments are equally informative: listeners identify words from the speech stream incrementally, continually updating their lexical search as the phonetic signal unfolds. As a consequence, segments earlier in words contribute more information to lexical identification than later segments. As a consequence, languages should not only optimize the total number of segments allocated to different words, but optimize the distribution of segments across the word relative to existing competitors in the lexicon. Here I'll show data from a range of languages that this is the case: words that are on average less predictable in context have more informative early segments, while tending to preserve a 'long tail' of more redundant later segments later.
Second, I'll briefly review work suggesting that this asymmetry in segment information at the word level may influence the evolution of phonological rules which impact lexical identification. In a typologically-balanced sample of 50 languages, we find that phonological rules which neutralize lexical distinctions (e.g., word-final obstruent devoicing in German) are common at word-ends, but very rare at word-beginnings.
Both of these patterns are consistent with the hypothesis that language change is influenced by a tendency for speakers to reduce redundant phonetic material while preserving more informative material.
When morphology is more than mere form: Evidence from Maltese
Adam Ussishkin, University of Arizona
Words consist of a phoneme or letter sequence that maps onto meaning. Most prominent theories of both auditory and visual word recognition portray the recognition process as a connection between these units of form and a semantic level. However, there is a growing body of evidence in the priming literature suggesting that there is an additional, morphological level that mediates the recognition process. To what extent does this level represent more than just form and meaning overlap between related words? And can a relatively abstract relationship at the morphological level nonetheless provide a pathway for word recognition? In this talk, I report on two experiments on the Semitic language Maltese investigating the extent to which root morphemes facilitate visual and auditory word recognition, and to what extent potential priming effects are independent of the form overlap typically inherent in morphological relationships. These experiments make use of the visual masked (Forster and Davis, 1984) and auditory masked (Kouider and Dupoux, 2005) priming techniques. The results of the experiments show that not only do roots facilitate visual and auditory word recognition in Maltese, but that these morphological effects are independent of form overlap effects.