Dans le cadre des séminaires de Professeurs Invités organisées par le LabEx Empirical Foundations of Linguistics, nous avons le plaisir de recevoir le Professeur Adamantios Gafos pour un cycle de quatre conférences
Adamantios Gafos – Excellence area of Cognitive Science at University of Potsdam (Germany) and Senior Scientist at Haskins Laboratories (USA)
Programme de la série des 4 conférences :
Lecture 1 : Adamantios Gafos I : Phonetic nomograms for abstract phonological units (joint work with Jason Shaw, Philip Hoole, Chakir Zeroual and Simon Charlow) – date : Friday 25th March 2016 / 14h-16h
We pursue an analysis of the relation between qualitative syllable parses and their quantitative phonetic consequences. To do this, we express the statistics of a symbolic organization corresponding to a syllable parse in terms of continuous phonetic parameters consonantal plateau durations, vowel durations, and their variances. These parameters can be estimated from continuous phonetic data. This enables analysis of the link between symbolic phonological form and the continuous phonetics in which this form is manifest. We illustrate the predictions of different syllabic organizations and derive a number of previously experimentally observed and simulation results. Specifically, we derive the canonical phonetic manifestations of different syllabic organizations but also the result that, under certain conditions we can make precise, the phonetic indices of one organization can change to a range of values characteristic of the other, phonologically distinct organization. Finally, we explore the behavior of phonetic indices for syllabic organization by progressively increasing the size of the lexical sample and concomitantly diversifying the phonetic context over which these indices are taken.
Suggested readings :
2015, Shaw, J. and A. Gafos. Stochastic time models of syllable structure. PLoS ONE 10(5), DOI : 10.1371/journal.pone.0124714.
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0124714
2011, Shaw, J., Gafos, A., Hoole, P., Zeroual, C. Dynamic invariance in the phonetic expression of syllable structure. Phonology 28, 455-490.
Lecture 2 : Adamantios Gafos II : Kinematics and dynamics of gesture (joint work with Tanner Sorensen) date : Friday 1st April 2016 / 14h-16h
We propose a theory of gestural timing. It is a theory of how a gesture determines change in vocal tract state (e.g., change in constriction degree) based on the vocal tract state. A core postulate of the theory is that no executive time-keeper determines change in vocal tract state. That is, it is a theory of intrinsic timing. We compare the theory against others in which an executive time-keeper determines change in vocal tract state. Theories which employ an executive time-keeper have been proposed to correct for disparities between theoretically predicted and experimentally observed velocity profiles. Such theories of extrinsic timing make the gesture a nonautonomous dynamical system. For a nonautonomous dynamical system, the change in state depends not just on the state, but also on time. We show that this nonautonomous extension makes surprisingly weak kinematic predictions both qualitatively and quantitatively. We propose instead that the gesture is a theoretically simpler nonlinear autonomous dynamical system. For the proposed nonlinear autonomous dynamical system, the change in state depends nonlinearly on the state (and does not depend on time). This new theory provides formal expression to the notion of intrinsic timing. Furthermore, it predicts experimentally specific relations among kinematic variables which we can verify in datasets we have examined.
Suggested readings :
Mottet, D., & Bootsma, R. J. (1999). The dynamics of goal-directed rhythmical aiming. Biological cybernetics 80(4), 235-245.
http://diabeto.enseeiht.fr/download/handwriting/Mottet_Bootsma.pdf
1980, C A Fowler. Coarticulation and theories of extrinsic timing. Journal of Phonetics 8, 113–33.
Lecture 3 : Adamantios Gafos III : Linking perception and production in a cue-distractor paradigm (joint work with Kevin Roon and Chris Kirov) – date : Friday 8th April 2016 / 14h-16h
When speaking words, a person must retrieve the phonological representation of a target lexical item by assembling a set of parameter values that specify the required vocal tract action. We present a computationally explicit model of the process by which phonological production parameters are set. The model focuses on a specific task that requires the concurrent use of both speech perception and production, which in turn allows us to shed light on the nature of the representations involved in the perception-production link. Specifically, the proposed model formalizes how ongoing response planning is affected by perception and accounts for a range of results reported across previous studies. The key unit of the model is that of the dynamic field, a distribution of activation over the entire range of values associated with each representational parameter. The setting of parameter values takes place by the attainment of a stable distribution of activation over the entire field, stable in the sense that it persists even after the response cue in the above experiments has been removed. This and other properties of representations which have been taken as axiomatic in previous work are derived by the dynamics of the proposed model.
Suggested readings :
Roon and Gafos, in press, Perceiving while producing. Journal of Memory and Language. http://www.sciencedirect.com/science/article/pii/S0749596X16000073
Schoner et Erlhagen 2002 Dynamic field theory of movement preparation. Psychol Rev. 2002 Jul ;109(3):545-72
Lecture 4 : Adamantios Gafos IV : Issues in the morphology and phonology of Arabic – date : Thursday 14th April 2016 / 15h-17h
How different is the phonology and morphology of nontemplatic (concatenative) word formation from that of templatic (nonconcatenative) word formation ? We will focus on the Arabic verbal system, the prototypical example of templatic morphology, with the aim of deriving some of its distinctly special traits from basic principles. The key novel aspect of the approach is its focus on paradigms. The main result is that the paradigm coupled with general phonotactic constraints sets limits on the theoretically possible diversity of stems within that paradigm. The core analysis will be on Classical Arabic. However, we will bring in data from dialects which justify the approach and/or permit further theory development.
Suggested readings :
Gafos, A. 2003, Greenberg’s asymmetry in Arabic : a consequence of stems in paradigms. Language 79:2, pp. 317-357 (distributed earlier as Gafos, A. 2001. Deriving Greenberg’s asymmetry in Arabic. In Marcel den Dikken, Ed., CUNY/NYU Working Papers in Linguistics, pp. 1–47. http://www.gc.cuny.edu/CUNY_GC/media/CUNY-Graduate-Center/PDF/Programs/Linguistics/LIBA/Gafos2001.pdf)
McCarthy, J. J. 2001. Optimal paradigms. Rutgers Optimality Archive 485. Available at : http://roa.rutgers.edu/files/485-1201/485-1201-MCCARTHY-0-2.PDF, subsequently published as
McCarthy, J. J. 2005. Optimal paradigms. In Paradigms in phonological theory, ed. Laura Downing, T.A. Hall, and Renate Raffelsiefen, 295–371. Oxford : Oxford University Press.