Atypical signed language development: A case study of challenges with visual–spatial processing

Abstract

In signed languages, the articulatory space in front of the signer is used grammatically, topographically, and to depict a real or imagined space around a signer and thus is an important consideration in signed language acquisition. It has been suggested that children who acquire signed languages rely on concomitant visual–spatial development to support their linguistic development. We consider the case of a native-signing deaf adolescent female with average intelligence who had been reported to struggle with spatial aspects of American Sign Language (ASL) as a child. Results of a battery of linguistic and nonlinguistic tests suggest that she has relatively good ASL skills with the exception of some specific difficulties on spatial tasks that require attention to ASL and nonlinguistic topographic space or changes in visual perspective (e.g., classifiers and referential shift). This child has some difficulties with visual–spatial abilities, and we suggest that this has affected her acquisition of those aspects of ASL that are heavily dependent on visual–spatial processing.

• Sign language impairment
• Perspective taking
• Visual spatial
• Classifiers
• Referential shift
• Visual–spatial sketchpad.

This article has benefited from the insights and comments of three anonymous reviewers and an editor of Cognitive Neuropsychology, and we are grateful for their input. We thank the child who we worked with extensively, the family, and the school for their willingness to allow this work to be done. This project has benefited from the insights and time of many people along the way, and there are too many to name them personally here. Among those individuals are students, school professionals, and research colleagues. We are indebted to all of you for your time and interest in this project. And, we thank VL2 (the NSF Visual Language and Visual Learning Center) for its support of this work.

This research was supported by the National Science Foundation Science of Learning Center Program, under cooperative agreement number SBE-0541953. Any opinions, findings, and conclusions or recommendations expressed are those of the authors and do not necessarily reflect the views of the National Science Foundation.

Notes

¹ It is also the case that spoken language is acquired by deaf, hard of hearing, and hearing children who are exposed to a signed language from birth or very early in their childhood. Those children are particularly interesting because they acquire a visual language and an auditory language—often simultaneously. These interesting, albeit complex, cases of language acquisition should be considered in more detail—especially with respect to the topic of communication disorder.

² Penn, Commerford, and Ogilvy (2007) have also investigated signed language disorders in deaf adult signers of South African Sign Language (SASL).

³ Tests of significance were not reported by Bellugi and colleagues (1990) for the data that they reported.

⁴ The term classifier, in the context of signed languages, most commonly refers to handshapes that are used to depict entire classes of objects, such as an ASL 3-handshape to refer to most vehicles and a bent-V handshape to refer to most animals. However, there are additional types of classifiers. See Supalla (1982) for an early description of ASL classifiers, including developmental milestones for their acquisition. Emmorey and colleagues (1995) discuss distinctions between referential and topographical uses of space.

⁵ The term depictive is not common in the literature to refer to a category of the use of space, although there are limited writings about a device referred to as depiction in ASL (Dudis, 2007). The use of the term depictive in this manuscript is intended to simply provide a way to refer to bodily (e.g., torso/head/eyegaze) actions of the signer that depict how characters/objects interact. This has been described by some authors as “Viewer space” (Emmorey & Falgier, 1999). See Lillo-Martin, 1995 for a grammatical analyses of referential shift. Some authors combine functions II and III, label function I “abstract use of space”, and consider an additional category referred to as “shared space”, where the signer references objects/people in the actual signing environment (Emmorey et al., 1995; Emmorey, 2002).

⁶ This is a pseudonym chosen to protect the identity of the child.

⁷ The English is limited to a carrier phrase that is mostly the same throughout the 12 items, with the exception of changing with respect to the target items under consideration for each item.

⁸ We have collapsed two categories of errors from Hegarty and colleagues (2004)—namely, reflection errors and nonreflection errors—into a single category. For our purposes, both of those errors represent deviations from the correct response that lie within the same quadrant as the correct response. In other words, the errors can range from 1° to 89°, though they do not cross the horizontal (top–bottom) or vertical (midline) lines for the analysis.

⁹ Age reports are given in years and months (year;month) or simply years.

¹⁰ One factor that may have influenced Alice's retelling is that the researchers were also present when Alice viewed the cartoon stimulus video. Alice may have assumed that she didn't need to provide many details since the researcher had already seen the story, too. While this might account for a lack of detail in Alice's narrative, it doesn't explain why her referencing information was vague or unclear at times.

¹¹ Review of other examples of Rabbit and Tortoise narratives as told by a handful of similarly aged native-signing deaf adolescents (some of whose assessment data are reported for comparison purposes in the Results section) confirms that the starting line is generally depicted with a classifier that is produced parallel to the signer's torso—as opposed to at a diagonal, as produced by Alice. No other child within this set produced a diagonally oriented starting line.

¹² After the PTCT was administered to Alice it was determined that one of the items within Block 3 did not have a correct choice. For this reason, that item was removed from these analyses. Thus, all percentages for the results reported here were calculated based on 19 items rather than 20.