Casey Ferrara (University of Chicago), Susan Goldin-Meadow (Mercator Fellow), Thomas A. Finkbeiner, Nina-Kristin Meister, Markus Steinbach, Patrick C. Trettenbrein (Parts of Speech and Iconicity in German Sign Language (DGS)), Vanessa W. Y. Tsang (University of Göttingen)
General Background
Iconic Modification is a fundamental aspect of American Sign Language (ASL) and other sign languages, enabling signers to convey complex ideas and emotions with precision and nuance. This process involves altering the shape, orientation, or movement of a sign to create a modified sign that is related to the original but carries additional relevant information in a simultaneous manner. In general, deaf signers can use simultaneous and sequential expressions for describing the same scene. For example, a description of a person running fast could be signed either by using the appropriate classifier sign for “person” and moving it at high speed through the signing space—thereby simultaneously expressing relevant information about who is moving and in what manner—or by conveying the same information using a sequential strategy, first producing the lexical signs for “person”, “running”, and “fast”.
To date, signers’ preference for either type of expression has not yet been systematically studied in German Sign Language (DGS). Moreover, it is not known whether such constructions—which could be argued to contain a larger gestural component than purely lexical signs—are processed in the primarily left-hemispheric language network, which is known to respond to grammatical structure independent of the modality of language use (Friederici et al., 2017; Trettenbrein et al., under review).
Motivation for this Collaboration
Ferrara et al. (in press) explored the gradient modification of motion description in ASL by comparing the sequential use of lexical signs and the more simultaneous use of classifier or depicting constructions. Following this line of investigation, this project plans to adopt the same production paradigm to German Sign Language (DGS) for a cross-linguistic comparison of how these two types of signs can be modified in historically unrelated sign languages (Study 1). In addition, we intend to include a comprehension paradigm that includes both of these types of expressions (i.e., simultaneous vs. sequential) as an additional experiment in an already planned fMRI acquisition with deaf signers of DGS at the Max Planck Institute in Leipzig (Study 2). Video stimuli for this comprehension experiment will be recorded with the aid of a native deaf signer in the SignLab in Göttingen.
Study 1 (Production Paradigm, to be tested behaviourally):
The paradigm from Ferrara et al. (in press) will be adapted to DGS. This production task will then be run with a target sample size of 20 deaf participants who use DGS as their primary and preferred means of communication in the SignLab in Göttingen, and possibly also prior to MRI acquisitions at the MPI in Leipzig. The goal of this study is to determine which strategy naïve signers of DGS prefer in different contexts (i.e., whether they prefer simultaneous over sequential constructions or vice versa).
Study 2 (Comprehension Paradigm, to be tested in fMRI):
Drawing on the intuitions of one co-author who is a deaf native signer of DGS, we will record video stimuli showing both simultaneous and sequential productions in DGS. Participants will be asked to watch these videos while undergoing fMRI scanning and will indicate via button press after watching every video how grammatically acceptable they considered the particular sequential or simultaneous construction they had just watched. The data will be collected as part of a larger fMRI acquisition that is already planned as part of the ViCom project “Parts of Speech and Iconicity in German Sign Language (DGS)”. The goal of this study is to determine whether the primarily left-hemispheric language network (1) responds to classifier constructions—which arguably contain a larger gestural component—similarly to how it is known to respond to lexical signs, and (2) processes simultaneous and sequential constructions in DGS in the same manner.
When, Where, and How the Collaboration Will Take Place
The collaboration will happen remotely in the form of regular meetings of the entire project team over Zoom or another tool for video meetings. Data will be collected at the SignLab at the University of Göttingen for the production task (Study 1) and at the Max Planck Institute in Leipzig (Study 1 and Study 2). Signers of DGS will be recruited around April–May 2025 for an elicitation task, wherein the video stimuli of the task will be adapted from Ferrara et al.’s (in press) study. In Study 1, participants will be asked to describe the motion events using, first, the lexical signs and then the classifier constructions. As for the stimuli for the fMRI study, participants will be asked to comprehend pre-recorded videos of short motion events produced by a deaf DGS signer (i.e., the deaf researcher within the team). These videos will also be recorded based on the adaptation of Ferrara et al.’s (in press) paradigm to DGS in February–March 2025.
We expect data collection for Study 1 to be completed by autumn 2025; data collection for Study 2 should be complete before the end of the year. Analyses will be performed by team members in Germany as well as in the United States. The goal is to have a manuscript draft discussing the data from Study 1 ready by the end of 2025. Data from Study 2 should be analysed at the beginning of 2026, with a manuscript based on the data being written up and at least available as a preprint in the first half of the year 2026.
Goals
The adaptation of Ferrara’s study to DGS aims to further investigate whether the three dimensions of motion (in speed, direction, and path) are modified in similar ways as described in ASL, contributing to the broader discussion of gradience in linguistic systems in the signed modality. Since DGS and ASL are unrelated, the comparison of these lexical and depicting signs may suggest whether the limitations are language-specific. If the limitations are likely due to gestural constraints, we would expect to observe similar patterns as Ferrara’s findings. Moreover, it is not yet known whether such constructions, which could be argued to contain a larger gestural component than purely lexical signs, are processed in the primarily left-hemispheric language network, which is known to respond to grammatical structure, independent of the modality of language use (i.e., spoken, written, or signed).
Planned Steps
The lexical and depicting signs in DGS to be shown as prompts will be prepared based on Ferrara’s study on ASL, though some items will be omitted as they are phonologically restricted from modification (e.g., the lexical sign for RUN is body-anchored in DGS). Video pairs of altered events will be directly taken from the ASL paradigm. We intend to recruit a total of 20 Deaf participants from Germany for Study 1 (i.e., the Production Paradigm). Data for Study 1 should be collected around May to July 2025. Participants may also additionally take part in Study 2 in the MRI lab (i.e., the Comprehension Paradigm); however, the samples will not be identical due to safety regulations and restrictions regarding whether participants can participate in MRI experiments for research purposes (e.g., metal implants, particular medical conditions, etc.). Data collection for the fMRI experiment will take place as part of a larger fMRI data acquisition that will take place as part of the project “Parts of Speech and Iconicity in German Sign Language (DGS)” from February to December 2025.