Fundamentals of formal properties of nonmanuals: A quantitative approach

Introduction

Sign languages, in addition to using the hands, also use positions and movements of other articulators: the body, the head, the mouth, the eyebrows, the eyes, and the eyelids, to convey lexical, grammatical, and prosodic information. This linguistic use of the nonmanual articulators is known as nonmanuals.

Hypothesis

Contrary to current assumptions in the field of sign linguistics, this project proposes the hypothesis that all sign languages use the same basic universal building blocks (nonmanual movements). However, each language is different in how it combines these building blocks both sequentially and simultaneously.

Differences Among Languages

Languages also differ in the following aspects of nonmanuals:

1. Regularity
2. Frequency
3. Alignment properties

Methodology

In order to test this hypothesis, the project will investigate formal properties of nonmanuals in five geographically, historically, and socially diverse sign languages. The methodology includes:

• Using data from published naturalistic corpora of the sign languages
• Employing Computer Vision for extracting measurements of the movement of nonmanual articulators
• Applying a statistical technique of Functional Data Analysis for a quantitative comparison of dynamic nonmanual contours

This will result in the first quantitative formal typology of nonmanuals grounded in naturalistic corpus data.

Methodological Development

The novel methodology proposed in this project requires testing, adjustment, and development, which constitutes an important component of the project. The developed methodological pipeline will be a secondary output enabling large-scale reliable quantitative research on nonmanuals in the future.

Cross-Modal Comparison

Finally, the established typology of formal properties of nonmanuals in the five sign languages will serve as a basis for a cross-modal comparison between nonmanuals and prosody/intonation in spoken languages. This comparison aims to separate truly universal features of the human linguistic capacity from the effects of the visual versus auditory modalities.