Periodic Reporting for period 4 - MOR-PHON (Resolving Morpho-Phonological Alternation: Historical, Neurolinguistic, and Computational Approaches)
Berichtszeitraum: 2021-04-01 bis 2022-09-30
In morpho-phonological alternations, the shapes of morphemes can differ between morphologically related word forms. For example, the morpho-phonologically related words revére – réverence differ with respect to where the main prominence falls on the word and how the stressed vowels differ. The second vowel in the verb 'revere' has a stressed [iː] (cf. 'bee') while the stressed vowel in the noun 'reverence' has [ɛ] (cf. 'bell'). The opaque phonological relationship between morphologically related forms has been a longstanding challenge in theoretical, historical, psycho- and neuro-linguistics, and computational linguistics alike. Morpho-phonological alternations of all kinds have been analysed across the languages of the world; but fundamental questions have remained controversial or indeed unasked:
▪ Why do they exist in the first place and why are they so widespread?
▪ How do they come about and what is their diachronic time-course?
▪ How are they represented in mental lexicons and how are they processed?
The position we advocated was that morpho-phonological variants are not listed and stored independently in the mental lexicon, but rather are mapped onto single abstract representations. This is a controversial position, and its defence required the systematic study of types of alternations and their histories, and precise hypotheses about the nature of mental representations. We examined different types of alternations throughout history across many languages (including Bengali, Dutch, English, German, Mandarin, Swedish) and focused on the internal structure of words under three broad areas:
A) Structure of affixation, morphological complexity and processing.
B) Morphophonological alternations (including metrical patterns) and role of affixation in loans in Germanic, keeping track of the abstract phonological representations
C) Compounding: conflicts between phonological and lexical word formation.
Address (URL) of the project's public website
http://brainlab.clp.ox.ac.uk/
For (B), we considered the notions about the way in which analogical extensions and prosodic constraints interact even with loanwords. By focusing on medieval stages of English, Dutch and German, we found that metrical patterns in Germanic have consistently remained on the first syllable regardless of phonological alternations. Romance loans, however, caused havoc in the individual metrical systems, particularly due to affixed words. We have shown that, despite the large number of loans and substantial increase in complex words in the lexicons, the basic foot structure has remained trochaic. The critical difference is that English maintains its preference not to stress final syllables, making the main stress fall away from the right edge. In contrast, German and Dutch do allow final stressed syllables if they have the relevant weight. This suggests that all three languages have maintained their basic foot structure and presence or absence of heavy syllables at the right edge of words, despite the onslaught of loans.
For (C), our results supported the idea that compounding in English and Bengali carry similar lexical and morphological properties, but prosodically, the outputs can be very different. We also found evidence through naming tasks that visual concatenation (e.g. time zone vs. timeline) is not a reliable indicator of compounding in English: prosodic output can be very different from the visual input.
In developing our speech recognition model, we identified an approach that results in an Automatic Speech Recognition (ASR) system that requires relatively little training, can be adapted flexibly to new languages (even those where training data in the form of annotated speech recordings may be sparse), and employs theoretical insights from the study of how the human brain processes speech to emulate this process on an app. Importantly, it aims to target those features that are essential to human understanding of speech and ignores or tolerates those that can vary across speakers or utterances.In all, the PI as well as the members of the team have given 21 talks (invited as well as at conferences where we submitted abstracts). Presentations were made at various linguistic conferences across the world including Toronto (Canada), Canberra (Australia), Amsterdam (The Netherlands), Berkeley (USA), New Delhi (India), Zurich (Switzerland) as well as at several universities across the UK.