The articulatory basis of positional asymmetries in phonological acquisition

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Linguistics and Philosophy, 2009.Cataloged from PDF version of thesis.Includes bibliographical references (p. 250-276).Child phonological processes that lack counterparts in adult phonological typology have long posed a problem for formal modeling of phonological acquisition. This dissertation investigates child-specific processes with a focus on the phenomenon of neutralization in strong position, whereby children preferentially neutralize phonemic contrast in precisely those contexts seen to support maximal contrast in adult systems. These processes are difficult to model without making incorrect predictions for adult typology. Here, it is argued that all genuinely child-specific processes are driven by constraints rooted in child-specific phonetic factors. In a phonetically-based approach to phonology, if there are areas of divergence in phonetic pressures across immature and mature systems, differences across child and adult phonologies are predicted rather than problematic. The phonetically-based approach also explains the developmental elimination of child-specific processes, since in the course of typical maturation, the phonetic pressures driving these effects will cease to apply. Because children's speech-motor control capabilities are known to diverge from those of the skilled adult speaker, it is posited that articulatory factors play the dominant role in shaping child-specific phonological processes. Here it is argued that children have difficulty executing discrete movements of individual articulators, notably the tongue. By moving the tongue-jaw complex as a single unit, the child speaker can reduce the number of degrees of movement freedom and also rely on the action of the motorically simpler mandible to achieve articulatory targets.(cont.) The effects of mandibular dominance have previously been argued to play a role in shaping sound patterns in babbling and early words (MacNeilage & Davis, 1990). The preference for jaw-dominated movement can be seen to recede over time as the child establishes more reliable articulatory control. However, here evidence from the productions of older children is presented indicating that these effects continue to have an influence in later stages of development than has been previously documented. The pressure to use simultaneous movements of the tongue-jaw complex, formalized in a constraint MOVE-AS-UNIT, is argued to play a role in shaping child-specific processes including positional velar fronting, prevocalic fricative gliding, and consonant harmony. In the present approach, children's tendency to neutralize contrast in strong positions arises as MOVE-AS-UNIT interacts with asymmetries in the force and duration of articulatory gestures across different prosodic contexts. The incorporation of child-specific phonetic factors makes it possible to account for complex patterns of conditioning in child speech processes that would under other assumptions be extremely challenging to model.by Tara K. McAllister.Ph.D

Covert contrast in child phonology is not necessarily extragrammatical

Covert contrast in child phonology is not necessarily extragrammatica

The Pakaru ‘Pipeline’: Māori and Pasifika Pathways within the Academy

We examine the academic ‘pipeline’ for Māori and Pasifika graduates and illustrate the chronic under-representation of Māori and Pasifika in permanent academic positions in New Zealand universities. We identify areas within higher education where significant opportunities are being lost for the recruitment and retention of Māori and Pasifika. The narratives of Māori and Pasifika post-doctoral researchers, research associates and professional teaching fellows provide further insight into the advantages and disadvantages of these positions. Lastly, we propose a Pacific alternative metaphor ‘Pacific Navigation of Academic Pathways’ based on Pacific navigation, as opposed to the more commonly used term ‘pipeline’, in order to capture the nuances of Pasifika and Māori experiences

Classifying Rhoticity of /r/ in Speech Sound Disorder using Age-and-Sex Normalized Formants

Mispronunciation detection tools could increase treatment access for speech sound disorders impacting, e.g., /r/. We show age-and-sex normalized formant estimation outperforms cepstral representation for detection of fully rhotic vs. derhotic /r/ in the PERCEPT-R Corpus. Gated recurrent neural networks trained on this feature set achieve a mean test participant-specific F1-score =.81 ({\sigma}x=.10, med = .83, n = 48), with post hoc modeling showing no significant effect of child age or sex.Comment: To appear in Proceedings of the Annual Conference of the International Speech Communication Association, INTERSPEECH 202

The Pakaru ‘Pipeline’: Māori and Pasifika Pathways within the Academy

We examine the academic ‘pipeline’ for Māori and Pasifika graduates and illustrate the chronic under-representation of Māori and Pasifika in permanent academic positions in New Zealand universities. We identify areas within higher education where significant opportunities are being lost for the recruitment and retention of Māori and Pasifika. The narratives of Māori and Pasifika post-doctoral researchers, research associates and professional teaching fellows provide further insight into the advantages and disadvantages of these positions. Lastly, we propose a Pacific alternative metaphor ‘Pacific Navigation of Academic Pathways’ based on Pacific navigation, as opposed to the more commonly used term ‘pipeline’, in order to capture the nuances of Pasifika and Māori experiences

Applying an Established Exposure Response Prevention Protocol for Young People With Tourette Syndrome in an Intensive, Group Format: A Feasibility Study

Background: The motor and vocal tics that characterise Tourette syndrome are stigmatizing and impact on quality of life. Behavioural interventions such as Exposure Response Prevention or Comprehensive Behavioural Interventions for Tics are first line treatment for Tourette syndrome, but availability is limited. This study is the first to explore the impact of an established manualised Exposure Response Prevention treatment protocol, developed for individual therapy, but here uniquely delivered intensively, to a group. // Methods: A naturalistic study comprised of a consecutive series of children (N = 20), aged 8–16 years (M = 12, SD = 2.17) were offered Exposure Response Prevention in one of two groups, delivered in series within a specialist clinic. Young people received the equivalent of 12 sessions (matching the manualised individual protocol). // Results: The YGTSS and Giles de la Tourette Syndrome Quality of Life Scale for Children and Adolescents (Satisfaction Scale) showed significant improvement following treatment with moderate to large effect sizes. Thirty-five percent of children demonstrated a reliable improvement on the YGTSS Global Tic Severity score. // Conclusions: These data suggest an established Exposure Response Prevention protocol can be delivered in an intensive, group setting with a positive clinical outcome. Replication in a randomized controlled trial is an important next step

Acoustic-to-Articulatory Speech Inversion Features for Mispronunciation Detection of /r/ in Child Speech Sound Disorders

Acoustic-to-articulatory speech inversion could enhance automated clinical mispronunciation detection to provide detailed articulatory feedback unattainable by formant-based mispronunciation detection algorithms; however, it is unclear the extent to which a speech inversion system trained on adult speech performs in the context of (1) child and (2) clinical speech. In the absence of an articulatory dataset in children with rhotic speech sound disorders, we show that classifiers trained on tract variables from acoustic-to-articulatory speech inversion meet or exceed the performance of state-of-the-art features when predicting clinician judgment of rhoticity. Index Terms: rhotic, speech sound disorder, mispronunciation detectionComment: *denotes equal contribution. To appear in Proceedings of the Annual Conference of the International Speech Communication Association, INTERSPEECH 202

The Interdependency and Co-Regulation of the Vitamin D and Cholesterol Metabolism

From MDPI via Jisc Publications RouterHistory: accepted 2021-07-28, pub-electronic 2021-08-06Publication status: PublishedFunder: Harold Hyam Wingate Foundation; Grant(s): 16412Vitamin D and cholesterol metabolism overlap significantly in the pathways that contribute to their biosynthesis. However, our understanding of their independent and co-regulation is limited. Cardiovascular disease is the leading cause of death globally and atherosclerosis, the pathology associated with elevated cholesterol, is the leading cause of cardiovascular disease. It is therefore important to understand vitamin D metabolism as a contributory factor. From the literature, we compile evidence of how these systems interact, relating the understanding of the molecular mechanisms involved to the results from observational studies. We also present the first systems biology pathway map of the joint cholesterol and vitamin D metabolisms made available using the Systems Biology Graphical Notation (SBGN) Markup Language (SBGNML). It is shown that the relationship between vitamin D supplementation, total cholesterol, and LDL-C status, and between latitude, vitamin D, and cholesterol status are consistent with our knowledge of molecular mechanisms. We also highlight the results that cannot be explained with our current knowledge of molecular mechanisms: (i) vitamin D supplementation mitigates the side-effects of statin therapy; (ii) statin therapy does not impact upon vitamin D status; and critically (iii) vitamin D supplementation does not improve cardiovascular outcomes, despite improving cardiovascular risk factors. For (iii), we present a hypothesis, based on observations in the literature, that describes how vitamin D regulates the balance between cellular and plasma cholesterol. Answering these questions will create significant opportunities for advancement in our understanding of cardiovascular health