Sign communication in Cri du chat syndrome

Available online at www.sciencedirect.com

Journal of Communication Disorders 43 (2010) 225–251

Sign communication in Cri du chat syndrome Sonja Erlenkamp a,*, Kristian Emil Kristoffersen b,1 b

a Sør-Trømdelag University College, Department of Teacher and Interpreter Education, 7004 Trondheim, Norway University of Oslo, Department of Linguistic and Scandinavian Studies. P.O. Box 0137, Blindern, 0317 Oslo, Norway

Received 29 May 2009; received in revised form 3 February 2010; accepted 20 March 2010

Abstract This paper presents findings from a study on the use of sign supported Norwegian (SSN) in two individuals with Cri du chat syndrome (CCS). The study gives a first account of some selected aspects of production and intelligibility of SSN in CCS. Possible deviance in manual parameters, in particular inter- and/or intra-subject variation in the use of handshape is investigated. Second, the question is addressed to what extent the isolated signs and isolated speech are intelligible and to what extent the combination of signs and speech in SSN contributes to a better intelligibility compared to each part in isolation. Results showed inter-subject variation, as well as individual consistency of deviancy in phonetic handshape parameters. Both participants were slightly more intelligible in their sign articulation when signs and speech production were analyzed separately. Importantly, intelligibility was greatly increased when signs and speech were combined. This emphasizes the importance of SSN for facilitating communication in children with CCS. Learning outcomes: The reader will be able to identify Signed Supported Communication as an artificial communication form, which can be used as an aid for language development in different groups of children, including children suffering from Cri du chat syndrome. The paper shows the reader to recognize that although children with Cri du chat do not produce words or signs accurately, their intelligibility can improve when they use simultaneous combinations of words and signs. # 2010 Elsevier Inc. All rights reserved.

1. Introduction This paper examines some aspects of the use of Sign Supported Communication (SSC) in two Norwegian individuals with Cri du chat syndrome (CCS). The main objective is to describe and analyze some characteristics of their use of SSC, mainly variation in handshape, including inter- and intra-subject variation. Other important aims are to investigate the extent of consistency in the patterns of variation and the intelligibility of speech and signing in isolation as well as combined speech and signing. While the description of patterns of variation in sign production has been described for other groups of non-verbal children using sign communication, like autistic children (e.g. Seal & Bonvillian, 1997), there are no studies available on the use of signs in CCS or the effects of SSC on the intelligibility of the overall communication in CCS. The paper is organized as follows: in the present section we provide general background information on CCS as well as on SSC and the variety of SSC used in Norway; sign supported Norwegian (SSN). We also review relevant literature on language skills in CCS. This is followed by a brief outline of the

* Corresponding author. Tel.: +47 99294784; fax: +47 73 55 98 51. E-mail addresses: [email protected] (S. Erlenkamp), [email protected] (K.E. Kristoffersen). 1 Tel.: +47 22857634. 0021-9924/$ – see front matter # 2010 Elsevier Inc. All rights reserved. doi:10.1016/j.jcomdis.2010.03.002

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phonological structure of signs and some background information on the typical development of formal aspects of signs in sign acquisition. Section 2 presents the method employed in the study, and Section 3 presents the results. In Section 4 we discuss the results and suggest some topics for future research. Section 5 concludes the paper. 1.1. Cri du chat syndrome Cri du chat syndrome (CCS) is a rare genetic disorder with an estimated incidence between 1 in 15,000 births (Higurashi et al., 1990; Medina, Mariescu, Overhauser, & Kosik, 2000) and 1 in 50,000 births (Niebuhr, 1978; Wu, Niebuhr, Yang, & Hansen, 2005). The syndrome was first described by Lejeune et al. (1963), and is associated with a deletion on the short arm of chromosome 5 (hence also known as 5p syndrome). The size of the deletion ranges from region 5p15.3 to the entire short arm of the chromosome (Overhauser et al., 1994; Simmons, Goodart, Gallardo, Overhauser, & Lovett, 1995). In about 90% of the cases the deletion is de novo, i.e. not hereditary; in remaining cases it results from parental balanced translocations (Laczmanska, Stembalska, Gil, Czemarmazowicz, & Sasiadek, 2006). Clinical features vary considerably from patient to patient, but typically include a high-pitched cry in infancy and childhood (Sohner & Mitchell, 1991; Sparks & Hutchinson, 1980) and distinct facial dysmorphism. Malocclusion, hyper- and hypotonia, and delayed motor development are also common (Carlin, 1990), as well as microcephaly (Niebuhr, 1978). Patients with CCS show various degrees of intellectual disability. Cornish, Bramble, Munir, and Pigram (1999) reported in a study of 26 UK children with CCS that full-scale IQ, as measured by the Wechsler Intelligence Scale for Children (WISC-III) (Wechsler, 1992), varied from below 40 (four children) to between 40 and 57 (mean 47.81) (the remaining children). Individuals with CCS often have short attention span, hyperactivity, and show behaviour characterized by sterotypy, self-injury and aggression (Collins & Cornish, 2002). 1.2. Earlier studies on language skills in CCS All aspects of speech and spoken language development are delayed in individuals with CCS (see Kristoffersen, 2008b, for a review). A substantial number of individuals with CCS (reports vary from 23% to 50%) do not develop spoken language at all (Baird et al., 2001; Carlin, 1990; Cornish & Pigram, 1996; Wilkins, Brown, & Wolf, 1980). When those affected by CCS do develop spoken language, however, receptive language has been found to be significantly better than expressive language, but still language age was significantly below chronological age (Cornish et al., 1999; Cornish & Munir, 1998). In a study on comprehension of grammatical categories in one subject (who also participated in the present study, referred to as S1 below) Kristoffersen (2003d) reported comprehension of number and definiteness for nouns; number, definiteness and gender for adjectives; and tense and aspect for verbs. Wium (2006) attested knowledge of various inflectional patterns in the target language for three Norwegian individuals with CCS (see Wium & Kristoffersen, 2008, for a summary). A small number of studies have addressed the specifics of language production including phonetic and phonological development in Norwegian children with CCS. These children were found to have reduced speech sound inventories and variable and distorted consonant productions (Kristoffersen, 2003a, 2003c, 2004, 2008a). Furthermore, they have problems with phonation and have variable and overlapping vowel productions (Kristoffersen, 2003a, 2003d, 2005). Within the domain of inflectional morphology, Norwegian individuals with CCS have been shown to inflect verbs in the past tense (Wium, 2006; Wium & Kristoffersen, 2008). However, the performance of the individuals participating (three females aged 11, 14 and 22), which was based on an elicitation procedure, was also characterized by a number of errors: over-generalizations, imitation of input, lack of response, and substitution by semantically related verbs, errors which are also found among children with specific language impairment (SLI) (Bjerkan, 2000) as well as among typically developing children and adults (Ragnarsdo´ttir, Simonsen, & Plunkett, 1999). 1.3. Sign supported Norwegian and CCS in Norway As part of the educational support for different groups of children with special needs in Norway a communication system has been developed that combines speech and sign (henceforth Sign Supported Norwegian, SSN).2 The variety 2

The Norwegian term is ‘‘tegn til tale’’ (sign to speech) (Braadland, 1993).

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of SSC used in Norway was according to Suhr and Rognlid (2009) first developed in Denmark3 in 1969 by speech therapist Marianne Bjerrega˚rd and was implemented in Norway in a Norwegian version in the end of the 1980s. The main basis for SSN or SSD (Sign Supported Danish) is a combination of spoken language, gestures and borrowed signs from the national signed languages, often so called ‘‘natural signs’’ because of their transparent iconicity as used by native signers. In addition some signs were specifically developed for SSN. Other types of SSC have been developed in other countries, like the Amer-Ind Gestural Code developed by Skelly (1979) based on signs used by native American tribes. Sign supported communication (SSC) is in any case not to be confused with a natural signed language. While the latter has a grammar of its own that is independent of the surrounding spoken language, sign supported communication is dependent on the grammar of the surrounding spoken language. SSN in Norway is typically performed as a version of spoken Norwegian where the spoken words are accompanied by isolated, often nonmodified signs, though not every word is accompanied by a sign. Thus SSN is not the same as a signed form of spoken Norwegian, as for example found in ‘‘tegnspra˚knorsk’’,4 since typically only content words are accompanied by a correspondent sign in SSN. Many of the signs used in SSN are borrowed from Norwegian Sign Language (Norsk Tegnspra˚k; NTS), but signs designed specifically for use in SSN are used as well (Braadland, 1993). Some Norwegian children with CCS receive instruction in SSN. However, there has been no investigation of the outcome of SSN as educational method for these children. Our study thus aims at giving first insights in how SSN is used by children with CCS. SSC as an educational method has been investigated for children with Down syndrome (Launonen, 1996; Prevost, 1995) and results indicate that these children both produce and perceive signs and gestures better than speech. The outcome of the use of sign communication (not necessarily SSC, but also single signs without speech) has been investigated for autistic children in a number of studies (see Seal & Bonvillian, 1997, for a review). These studies show overall positive effects of the use of signs with these children, both regarding communication as such, but also concerning attention, motivation, and social behavior. There has, however, been great variation between subjects leading, amongst other things, to the suggestion that those children who failed to imitate signs might suffer from lowfunctioning motor skills. There is, however no valid evidence for this suggestion yet, since ‘‘little systematic information has been reported on either the fine motor development or on the incidence of motor disorders in children diagnosed with autism’’ (Seal & Bonvillian, 1997, p. 438), Thus, the present study might shed some more light on this question. Since motor issues are a main concern in CCS, error patterns in production of handshapes, movement and place of articulation similar to those reported in studies on sign communication in autistic children might also give some support to this claim concerning autistic children. Bonvillian (1999, p. 301) claims that ‘‘many of the findings from studies of sign language acquisition in mute, autistic children hold also for other groups of non-speaking, mentally retarded children’’. The results of the present study support this claim. The study will, moreover, add a new perspective to the investigation of positive effects of SSC to CCS and probably other groups of mentally retarded children struggling with the production of speech, concerning the degree of intelligibility of their communication. If motor control is an issue in children using SSC, it is important not only to investigate the sign production in SSC, but also how this impacts intelligibility of the subjects. The fact that SSN in Norway is to a high degree based on the manual parts of signs borrowed from NTS makes it possible to compare the parameters of signs of NTS to the parameters of signs produced by CCS children. 1.4. The phonological structure of signs As with the analysis of spoken words, signed language signs can be described as entities of meaning and form consisting of smaller parts which in themselves are not independent carriers of meaning (first described by Stokoe, 1960). These parts have been analyzed as comparable to the phonemes of spoken languages and thus have been called ‘phonemes’ in signed language research, even though the term is associated with sounds in view of its derivation from Greek wvnZ ‘pho¯ne¯’, meaning ‘voice’ or ‘sound’. The term is used in the description and analysis of parts of signed language signs to indicate that these phenomena are of the same linguistic level as the phonemes of spoken language. 3

Norwegian and Danish are closely related languages belonging to the northern branch of Germanic. Tegnspra˚knorsk is a signed form of Norwegian which can be used in combination with speech. Tegnspra˚knorsk was originally developed to help deaf children learning Norwegian and one of its features is the inclusion of articfical signs to visualize inflection patterns of spoken Norwegian. 4

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Table 1 Parameters in signed languages (following Battison, 1978; Stokoe, 1960). Manual parameters

Non-manual parameters

Handshape Hand orientation Place of articulation Movement and manner of articulation

Mouthing Eyebrow movement Eyegaze Cheek configuration Head/upper body orientation

Nevertheless, the types and uses of signed phonemes are not entirely comparable to sound phonemes because, due to the visual mode, there are different types of phonemes than in spoken languages. The different articulators in a signed language serve at the same time as part of the visible language signal leading to different kind of phonemes based on the different articulators. Thus we find handshape phonemes, place of articulation phonemes etc. These types of phonemes have been identified in signed language linguistics. They are classified with regard to a number of parameters; a central distinction is made between manual and non-manual parameters, and these again can be subdivided (see Table 1). Furthermore a larger extent of iconicity is found in signed language data, and this influences the structure of the language at all levels including the phonological level. The parameters in Table 1 provide a starting point for the analysis of sign production at the phonetic or phonological levels. In SSN, however, non-manual parameters are not part of sign production since only the manual parts of isolated signs are used in the educational programs introducing SSN to the users. Mouthing occurs as a meaningful communication unit in SSN, although not as part of the sign, but as part of spoken language production. For the signs analyzed in the present study, mouthing is identical to the articulated version of the respective Norwegian target words, including use of voice. Non-manual parameters were not included in the analysis. In addition to the parameters listed in Table 1, manual parameters can be further subdivided into those which define a class of forms which are finite in number and thus fully accountable and those parameters which appear to define a class with an infinite number of entities. Parameters like handshape and hand orientation have been identified as distinct phonemes in several different signed languages, and hand shape inventories have been proposed (see for example Greftegreff, 1991, for Norwegian Sign Language; Becker, 1997; Papaspyrou, 1990, for German Sign Language; Stokoe, 1960; Battison, 1974, for American Sign Language). Parameters like movement and manner of articulation on the other hand do not seem to fit into a phonemic matrix (Becker, 1997; Fuchs, 2004). In particular the parameter of movement seems to include an infinite number of different forms which are not distinguishable as phoneme categories through minimal pair analysis (Fuchs, 2004). Thus, the task of describing the whole phoneme system of at least one single signed language has not yet been successful. This shortcoming is probably due to the extensive use of iconicity in signed language grammar and phonology; the iconic use of parameters like movement and manner of articulation complicate the segmentation and identification of phonemes (Becker, 1997). The present study therefore concentrates first and foremost on the only manual parameter in NTS that has been accounted for in a phonemic manner – handshape (Greftegreff, 1991).5 Greftegreff described the handshape inventory of the NTS with 38 distinct handshapes; these are depicted in Fig. 1. This is so far the only analysis on handshapes in NTS and thus we have used this list as a basis for evaluating the handshape component of sign production by our subjects. There is also another reason why the handshape parameter is a good choice for investigation: in a study of the development of formal aspects in signed language acquisition Siedlecki and Bonvillian (1993) show that the handshape parameter is not used as correct and consistent in young children of deaf parents as for example the place of articulation (referred to as location in Siedlecki and Bonvillian study) or movement parameters.

5 Greftegreff (1991) points out, that though her description of the handshape inventory is done based on a phonemic description of NTS, it is – due to the visual channel of the language – difficult to determine whether the different features of the handshapes can be classified as phonemic or iconic features.

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Fig. 1. Handshape inventory in the NTS (Norwegian Sign Language, Norsk Tegnspra˚k) developed by Greftegreff and quoted by Thordason (2000, p. 41), printed with permission by the author.

Ideally, the present study would compare the production of handshape in our subjects with the production of handshapes in native signers of the same age. Unfortunately, to date there is no description of the course of children’s acquisition of formational aspects of location, handshape, and movement in Norwegian Sign Language.6 It is thus not possible for us to compare the sign production of our subjects to the production of these formational aspects with children of the same age using a signed language. Although there are some studies on the acquisition of these formal aspects in young children learning ASL (American Sign Language) (Morgan, Barrett-Jones, & Stoneham, 2007; Siedlecki & Bonvillian, 1993, 1997), and for one child acquiring Norwegian Sign Languages (von Tetzchner, 1994) these studies investigate children of a different age group, namely 5–18 months of age (Bonvillian). Additionally, handshapes differ between Norwegian Sign Language and American Sign Language. There are however some general results which can serve as important background information when examining how production of signs in our participants with CCS differs from other non-verbal children: – Subjects acquiring a signed language tended to make significantly more handshape and movements errors than location errors (Siedlecki & Bonvillian, 1993, for ASL) (von Tetzchner, 1994, for one child learning NTS). – The tendency to accurately produce the location aspect emerges early in sign language development. (Bonvillian, 1999). – Increased control of the parameters handshape and movement were reported between 13 and 18 months of age (Siedlecki & Bonvillian, 1997). – Handshape variation in sign language learners occurred between subjects, but there was a tendency towards substituting so called marked handshapes with unmarked handshape (Morgan et al., 2007).

6

There is one study (von Tetzchner, 1994) focusing on how the first signs are acquired by a Norwegian deaf child with hearing parents. This study, however, focuses on one deaf child and thus cannot be used as general description of the course of children’s acquisition of aspects of NTS.

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– Morgan et al. (2007) reported errors in movement produced by one deaf child in sign acquisition in the following ways: movement deletion, sign reduplication, movement and location enlargement, and movement insertion. – Motor development is suggested as one of the several factors influencing the development of the formal aspects of signing (Boyes Braem, 1990a, Boyes Braem, 1990b). 1.5. Research questions The use of SSN with children suffering from CCS is assumed to have positive effects on the children’s overall communication, in particular intelligibility of the children’s utterances. The Norwegian website foreldrehjelpen.net, a site which aims at helping parents to obtain information about different handicaps including CSS, is a proponent of this assumption, with the following statement: Tidlig introduksjon og opplæring i tegnspra˚k (tegn til tale) er et svært viktig hjelpemiddel.’’ (‘‘Early introduction to sign language (sign supported Norwegian) is extremely helpful.’’) (Our translation.) Although this assumption is based on experience in the field, it has not yet been tested as part of a scientific investigation what the effects of the use of signs with children suffering from CSS are. Seal and Bonvillian (1997) refer to a number of studies that have been conducted on the use of SSC with autistic children who had failed to acquire even a limited amount of spoken language. Results indicate positive effects of sign training with lowfunctioning autistic children. A natural starting point for an investigation on SSC in CCS would thus be to examine the production of SSN in subjects with this syndrome in order to see if and how their use of SSN deviates from correctly produced SSN and how it compares to the use of SSC in other groups of children with special needs, viz. autistic children. The latter is particularly interesting, because it has been suggested by Seal and Bonvillian (1997) that autistic children might suffer from apraxia leading to deviancy in the production of the formal parameters of sign. Since this study provides a first time analysis of the use of SSN in CCS we have first and foremost focused on variation in one single sign parameter, namely handshape, but we have also to some extent looked at two other parameters, viz. movement and place of articulation. Our primary objective was to compare handshapes in signs used in SSN produced by individuals with CCS with the expected handshapes in correctly produced signs used in SSN. The results of this analysis can be compared to results of similar studies conducted with groups of autistic children using SSC. To reach this objective we have addressed the following research questions:  Do the handshapes (and movement and place of articulation) produced by the participants deviate from the handshapes (movement, or place of articulation) of the target SSN signs?  If yes, to what extent is there inter- and/or intra-subject consistency in the patterns of deviancy?  Can these patterns be compared with patterns of deviancy found in other non-verbal children using sign communication? Additionally, we were interested in how the use of SSN in children suffering from CSS would effect the overall intelligibility of the children’s communication, leading to the following research question:  To what extent does SSN contribute to intelligibility in our participants as compared to the intelligibility of their produced signs or speech in isolation. Since this study is based on the analysis of data from only two individuals with CCS we have focused on the individual production of handshapes and the effect on sign intelligibility rather than on an overall outcome measurement for SSN. Based on the assumption that deviancy in sign and speech production is caused by – among others – motor difficulties, there can, however, be generated a hypothesis that:  Children suffering from CSS will be more similar regarding the use of the formal signs parameters: handshape, movement and place articulation to autistic children than to native signers the same age.

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Table 2 Consonant phonemes of Urban East Norwegian. Word initial Lab p b m f [

Ap

Q ? Q

Word medial Lam t d n s

Do k g

Glo

c¸ j

h

Lab p b m f [

Ap S * F Q ? Q O

Word final Lam t d n s l

Do k g E c¸ j

Glo

h

Lab p b m f [

Ap S * F Q ? Q O

Lam t d n s l

Do k g E

Glo

j

Table 3 Inventory of phones produced by S1.

Stop Nasal Fricative Approximant Trill

Labial

Coronal

Dorsal

p m f [

t n s, l

k E ,Q

Glottal

h j

B

2. Method 2.1. Participants Two girls raised in Norwegian-speaking environments participated in the study. Data were collected during two sessions, the first in June and the second in October 2005. Subject 1 (henceforth S1) was aged 11;7 and 11;11 at the 2 recording sessions.7 She had some spoken language, mostly one-word utterances, but also some multiword utterances at the time of recording. Her speech was characterized by frequent omissions and distortions of segments which made it difficult to understand what she was trying to say. S1 had received instruction in SSN from when she was 4 months old, and had used it daily for communication in kindergarden, at school, and at home. At the time of recording she had attended a special class for 6 years. Subject 2 (henceforth S2) was aged 14;3 and 14;7 at the two recording sessions. She had very little spoken language, expressing herself in one-word utterances. Her speech was heavily distorted, making it extremely difficult to understand her spoken utterances. S2 had received instruction in SSN both in kindergarden and at school. She also used it regularly to communicate. At the time of recording she had attended a special class for 8 years. Unfortunately, no systematic information on IQ and motor skills exist for these children. However, our observations during the recording sessions, together with information supplied by the parents, indicate that S1 functioned better than S2 both motorically and intellectually. The target language of both subjects was Norwegian, more specifically the variety known as Urban East Norwegian (UEN; see G. Kristoffersen, 2000, for an overview). The system of consonant phonemes in UEN is rendered in Table 2. An analysis of the two participants’ phonology in terms of contrastive phones has not been conducted, but the sheer number of phones in their phone inventories, given in Tables 3 and 4, shows that they have very few consonants as compared to the target language. However, there was also a clear difference between the two participants in terms of the size of their consonant inventories: S1 has a considerably larger inventory than S2.

7

Information in this and the following paragraph has been supplied by the subjects’ parents. Any errors are ours.

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Table 4 Inventory of phones produced by S2.

Stop Nasal Fricative Approximant

Labial

Coronal

Dorsal

p

t n s, l

k

2.2. Materials and methods The data are based on two video recording sessions for each subject. The first recording session was conducted with visual stimuli from everyday life based on a folder with pictures of objects. Pictures were selected which had previously been used in the classroom and were thus familiar to the participants. Appendix A presents a sequential list of the signs produced in response to picture stimuli. The first author, who conducted the analysis of the data afterwards, was not present during the recording sessions in order to avoid influences from a fluent signer. To trigger use of SSN both subjects interacted in the first session with a familiar teacher who had previously used SSN with them at school; video recording took place in a familiar school room. Previous studies (e.g. Seal & Bonvillian, 1997) have used the same method, i.e. videotaping interactions between a classroom instructor and the child in a room familiar to her/him. In our study, the teacher presented the subject with the folder containing pictures of everyday life items, such as clothes, fruit, bicycles etc.,8 and asked the subject to name the items in the pictures. If the subject replied without using a sign the teacher asked her if she also knew the sign and could produce it in SSN. Video recordings were made both of the teacher and the subject in order to control for the teacher’s input. To obtain more detailed data on specific handshapes and types of movement, and to increase the number of times the same sign was used, a second group of test data was collected by asking each subject to produce single SSN utterances matching specific Norwegian words for the months and colors. The second recording was with auditive stimuli given by a familiar person (a teacher or a parent) and focused on:  Repeated exposure to the same stimulus to get the same SSN signs several times.  Detailed recording of specific handshapes in combination with specific types of movement.  SSN signs familiar to both subjects. Examples: colors, names of month. The stimuli used in both sessions (based on pictures of objects in the first session and on names for colors and months in the second session) were not designed to trigger production of verbs. Verbs in signed production are often highly iconic (Liddell, 2003) and/or polymorphemic (Wallin, 1990), and are expressed by highly complex movement and up to several handshape shifts in one sign. Both aspects were regarded as disadvantageous for an initial study into SSN in CCS. Our study was therefore restricted to signs referring to objects or to abstract concepts. 2.3. Data analysis Data were analyzed in several steps in accordance with the research questions. All analyses were performed by the first author, a fluent, non-native signer with over 15 years experience in signed languages and over 10 years experience in signed language research. The researcher performing the analysis was hearing and trained in phonetic analysis of spoken languages as well as signed language analysis. The choice of a non-native signer trained in analysis of NTS signs was based on several premises. Firstly, there are very few native NTS signers trained to perform sign analysis, all 8

The pictures did not contain the Norwegian words for the items depicted. S2 was, however, presented by the teacher with some simple written sentences at the end of session 1. She was asked to go through the sentences together with the teacher, producing the signs accordingly.

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of them deaf and none of them having finished their Ph.D. yet. Secondly and even more importantly, since SSN is a mode of communication that is dependent on the combination of speech and signs it was crucial that the researcher could perceive both the speech part and the signed part to secure that the targets were identified properly. Since our subjects had been trained in using SSN by non-signers familiar only with the manual part of signs in SSN and not NTS, it was crucial that the researcher could identify consistent use of handshapes, movements and places of articulation in SSN signs produced by the teachers and not as signs produced by a native NTS signer. A native signer would evaluate these signs as being incorrect even though they might be correctly produced by our subjects in the manner they had been taught. The teacher’s sign production on the tape was used as an anchor point for how signs were expected to be produced. Using the teacher’s sign performance as anchor point for identifying the target has also been used by earlier studies (Seal & Bonvillian, 1997), because signs may have been produced differently by individual teachers functioning as language models for the subjects. Thirdly, it was also considered to be an advantage for the researcher to be able to perform a phonetic evaluation of both the signed part and the speech part of the SSN. As the first step in our analysis, each handshape produced by our subjects was transcribed phonetically and described with respect to any deviance from target handshape formations as expected in SSN. The target handshape was the handshape that would have occurred in the manual part of the sign if produced correctly. For handshapes known from NTS the target was identified by using Fig. 1 and deviance noted, i.e. individual finger bend, finger movement, closeness, palm orientation, overall tenseness and bend in the wrist. Since most of the SSN signs are borrowed from NTS, for most produced manual sign in the SSN there was a handshape target identified by the use of Fig. 1. However, two target handshapes occurred in the data for S1 that were not described in the NTS handshape inventory as presented in Fig. 1. These were handshapes from the International Hand Alphabet (a handshape system for spelling out individual letters of the spoken language). These were nevertheless included in our analysis. For twohanded signs, and for signs involving a handshape shift, both handshapes were included in the analysis. Correctly produced handshapes were thus described with reference to the corresponding NTS handshape according to categories presented in Fig. 19 and numbered sequentially (left to right, top to bottom). Note that Gretfegreff has arranged the handshapes in Fig. 1 according to similarity in form when possible, see for example handshapes 1–4 and 5–7. Following the identification of the target handshapes in the SSN signs produced by the two subjects, an evaluation was made based on comparison between the target handshape and the actual handshape produced. The degree of similarity between the produced handshape and the target was evaluated. If a handshape was found deviant, its phonetic quality was evaluated with reference to a four-point scale. The different values attributed were as follows: 4: The handshape was correctly produced or produced with only minor, non-phonemic and ineffectual deviance from the target. 3: The produced handshape showed clear similarity to the target, but there was still noticeable deviance. 2: The produced handshape differed from the target to an extent that correspondence with the target could not be recognized in the absence of additional contextual cues, such as other parameters in the sign. 1: The produced handshape was so deviant from the target, that it was perceived as belonging to a different target. The second step in our analysis was to evaluate the intelligibility of the signed part of the SSN signs produced by S1 and S2 as compared to the intelligibility of the spoken part alone and the intelligibility of the signed and spoken part in combination. These comparisons focused on the signed parts as unanalyzed wholes as they occurred in the utterances in isolated form, and was performed on the basis of visual input from the videos only. The purpose of this evaluation was to document intelligibility of the signed part independently of the spoken part and in turn their respective contributions to the intelligibility of the combined use of sign and speech. In this part of the analysis each signed part was given a value between 2 and 0 as follows: 2: The sign was correctly perceived in isolated form. 9

There was sometimes a consistent deviance which could also be identified in the teacher’s production. In these cases the teacher’s production was regarded as input for the child and thus the teacher’s handshape was set as target handshape.

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1: The sign could be perceived correctly if provided with context information as for example the sign before and after. 0: The signs in isolation provided no cues as to its meaning. Next, the speech component of the speech-sign-combination was evaluated in the same way as the sign component. Each speech component of the speech-sign combination was evaluated as unanalyzed whole with regard to its intelligibility in isolation. Again, the same scale only for speech with the values 0, 1 and 2 was used. Speech that were not accompanied by signing was excluded from this part of the analysis. Finally, the intelligibility of the speech-sign combination was evaluated. This evaluation relied both on the visual and the auditive information from the video, but without the additional contextual information such as the content of the folders (the folders and pictures were not recorded on the videos). A value between 0 and 2 was allocated to each speech-sign combination, with 0 referring to non-intelligible combinations, 1 referring to combinations that could be perceived correctly if the textual context was provided and/or the perceiver was familiar with the subject’s individual deviances, and 2 referring to fully intelligible combinations as before. Although the main focus in this study was on evaluating the correct production of handshapes, the expected production of hand orientation, movement and place of articulation of the target sign were compared to actual productions. Although it is possible to analyze the different manual parameters of a sign individually, they are perceived simultaneously and as a whole. Thus, deviances in any of these parameters will influence the intelligibility of the sign as a whole; accordingly, any major deviance in any of the manual parameters of a sign was recorded in the transcript. This information was used for an overall assessment of deviancy in sign production in the two subjects. Sign production and speech were separately assessed for intelligibility before addressing the intelligibility of the signspeech combination. 3. Results 3.1. The signed data The primary data used in this study comprised 64.5 min of video recording, 32 min for S1 and 32.5 min for S2. 119 different signs were produced by subject 1 and 78 by subject 2. In total 177 different sign occurrences were produced by subject 1 and 117 by subject 2. S1 produced 273 handshape tokens and S2 produced 157 handshape tokens. The difference in number between sign tokens and handshape tokens is due to the occurrence of two-handed signs and signs with handshape shift. The data consisted primarily of combined sign and speech. However, some isolated speech occurred in the data, but this was not included in the study. In contrast, incidences of isolated signing were part of the analysis. Not all possible handshapes of NTS occurred as possible targets in the stimulus material. Out of the 38 handshapes in Fig. 1, only 32 were expected in the data for subject 1 and 26 for subject 2. 3.2. General observations on variation in manual parameters of sign production Both subjects produced combinations of sign and speech, although this sometimes required prompting. S2 in particular had to be encouraged to use combinations of signs and speech. She had a tendency to employ either speech or signs when not explicitly asked to produce a combination. The data clearly show that both subjects had problems in producing signs accurately in accordance with the target. Non-accordance included errors or deviances in handshape, hand orientation, and also in movement and place of articulation. The inaccuracy in place of articulation led in some cases to misinterpretation of the signs due to minimal pairs based on place of articulation, e.g. S2’s production of the sign APRIL which (due to deviant place of articulation) was perceived instead as the sign TELEPHONE. Seal and Bonvillian (1997) report some of the same errors for autistic children, while this seems to be more uncommon for children acquiring a signed language at early age (e.g. Siedlecki & Bonvillian, 1993). Movement, although sometimes in its overall form correct, often corresponded less accurately to the target. In general there were larger movements in signs, and in particular where movement was unrelated to other body parts such as the other hand or the head. Additionally, movements where often reduplicated, an observation also made by Morgan et al. (2007) in their description of reduplication in sign language acquisition.

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This effect appeared to be larger for S2 than for S1. S2 had considerable variation in place of articulation while S1 performed consistently better on handshape targets. Both subjects often showed consistent deviancy of handshape in different occurrences of the same sign, while movement in signing varied more often also for occurrences of the same sign in both subjects. 3.3. Handshape variation in sign production Tables 5 and 6 present the expected target handshape numbers for each sign produced by S2 and S1, and the actual produced handshapes for each occurrence.

Table 5 Number of target handshapes and tokens produced by S2. Handshape

No. expected targets

No. tokens

Handshape

No. expected targets

No. tokens

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Table 5 (Continued ) Handshape

No. expected targets

No. tokens

Handshape

No. expected targets

No. tokens

Left hand column: the reference numbers for the handshape targets as laid out in Fig. 1 (left to right, top to bottom). Middle column: how often the target handshape was expected to occur in the data. The number on the left is the expected number of target handshapes in the dominant hand, the number following the slash indicates the expected number of occurrences of the target handshape in the non-dominant hand. When the sign was single-handed only the expected number for the dominant hand is given. Right column: the number of handshape tokens produced overall in the data that matched the target handshape; the figures are dominant/non-dominant as in the middle column.

3.3.1. Handshape variation in S2 The analysis showed a target handshape inventory for S2 consisting of 26 distinct handshapes. The actual produced handshape types in response to pictorial stimuli identified 25 different handshapes. All together S2 produced 157 handshape tokens. Four of the different handshapes occurred with a high frequency (see Table 5), viz. handshapes 3, 6, 22, and 33. The other handshapes occurred less frequently. These 4 handshape types represented 96 token handshapes out of a total of 157. Similar findings for handshape frequency were documented by Seal and Bonvillian (1997, p. 494) for autistic children. They report that ‘‘six handshapes – the 5-hand, B-hand, A-hand, G-hand, O-hand, and C-hand – constituted 83% of the total number of handshapes produced by the subjects’’. The 5-hand correspond to handshape 3 in our Fig. 1, the B-hand to handshape 8, the A-hand to handshape 33, the G-hand is similar to handshape 22, the O-hand to handshape 11, and the C-hand to handshape 10. Although there was only a small difference between the number of target handshapes and actual produced handshape types, there was no clear agreement between the occurrence of targets and types. The correct handshape type did not always appear when required by the target. Regarding the high frequency of four specific handshapes, these did not only occur in accordance with the target, but they also occurred as replacements for other target handshapes. This is usually also found in early sign language development (e.g. Morgan et al., 2007). For example, some handshape types appeared to be used as replacements for target handshapes which were not produced by S2. In other cases replacements were for targets which were within the repertoire of signs produced by the subject. As an example consider the use of handshape 14 by S2. In the sign SPISE ‘eat’ the required target was handshape 14. Instead S2 produced handshape 7. In the sign BANAN ‘banana’ the required target was a movement between handshapes 25–27. Here S2 produced a movement from 13 to 14. In a third sign AND ‘duck’ the appropriate handshape was a switch between target handshapes 13 and 14, and S2 correctly produced these handshapes. Thus the failure to produce the correct target handshape in one sign does not demonstrate that the subject is unable to produce the target handshape. 3.3.2. Handshape variation in S1 S1, like S2, showed a tendency towards target replacement. Of 34 expected target handshapes, 32 were actually produced by S1. Again the small difference in number between target handshapes and handshape types does not reflect

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˚ ‘blue’ where target a correlation between target handshape and type. S1 used for example handshape 3 in the sign BLA handshape 12 was expected. Later she produced handshape 12 in the sign SMØR ‘butter’, where target 8 was expected, while in the sign DØR ‘door’ she produced the target handshape 12 correctly. Of the 32 distinct handshapes produced by S1, handshapes 3, 8, 9, 12 and 22 occurred most frequently, together representing 178 out of a total of 273 tokens. In addition, some handshapes occurred at an intermediate frequency. These included 7, 27 and 33, representing a total of 33 tokens. The remaining 62 tokens were distributed over the remaining 24 handshape types. 3.3.3. Comparison of handshape production of both subjects As reported above, neither subject produced all 38 handshapes as described in the NTS handshape inventory. This was partly due to the stimulus material. However, both subjects showed replacement of target handshapes with another handshape from the handshape inventory. Table 6 Number of target handshapes and tokens produced by S1. Handshape

No. expected targets

No. tokens

Handshape

No. expected targets

No. tokens

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Table 6 (Continued ) Handshape

No. expected targets

No. tokens

Handshape

No. expected targets

No. tokens

Left: handshape targets. Middle: expected target numbers (dominant/non-dominant). Right: Number of target matches (dominant/nondominant). For further explanation see Table 5 legend.

Fig. 2. Degree of deviancy in handshapes for S1 and S2. The vertical axis presents the number of occurrences as a percentage of total signings, the horizontal categories are arranged according to deviancy score between target handshape and token handshape (from 1, no match; to 4; clear match to target).

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The evaluation of the degree of similarity between target handshape and token handshape revealed another difference between the subjects. Overall, S1 was better than S2 at producing a handshape similar to the target handshape (Fig. 2). Individual variation in sign performance has also been reported for autistic children (Seal & Bonvillian, 1997) 3.4. Intelligibility of signs, speech and a combination of both Although the analysis of intelligibility was based only on a qualitative evaluation, there were clear differences between subjects S1 and S2 (see Table 7). Compared to S2, a significantly greater number of signs were produced by S1 that were considered intelligible based on visual input only. The same can be observed for the evaluation of intelligibility of speech only (see Table 8). In contrast to the purely visual or purely auditive assessment, the intelligibility scores for combined sign and speech were markedly higher (Table 9). Again S1 showed an overall better intelligibility than S2. Comparison of intelligibility evaluation results for visual input of the signs only, versus speech only, versus combined sign and speech reinforced the conclusion that the intelligibility of the sign-speech combination is far greater for both subjects than sign or speech only or even the sum of both (Fig. 3). These findings demonstrate that, for both subjects, intelligibility was overall markedly increased when visual and auditive input were considered together, in other words, when they used SSN. Nevertheless, the analysis revealed a number of instances where poorly produced signs distracted from the intelligibility of speech and vice versa. In addition, Fig. 3 shows that both subjects score better on isolated sign intelligibility than on isolated speech intelligibility. Another important observation was the consistency of sign production in both subjects. Though both subjects showed some deviance from target in both the handshape parameter and others parameters of the sign, they nevertheless tended to be consistent in their production of signs. This may have led to partial familiarization of the

Table 7 Intelligibility of signings based on visual input only.

S1 S2

Total number of occurrences

Value 2

Value 1

Value 0

177 117

57 16

85 51

35 50

Intelligibility scores were: fully intelligible (value 2); intelligible but only when contextual information was provided (value 1); not intelligible based on visual input only (value 0).

Table 8 Intelligibility of speech based on auditive input only.

S1 S2

Total number of occurrences

Value 2

Value 1

Value 0

151 99

37 8

77 52

37 39

Intelligibility scores were: fully intelligible (value 2); intelligible but only when contextual information was provided (value 1); not intelligible based on auditive input only (value 0).

Table 9 Intelligibility of speech-sign combinations. Total number of occurrences S1 S2

151 99

a

Value 2

Value 1

Value 0

103 42

36 39

12 18

Intelligibility scores were: fully intelligible (value 2); intelligible but only when contextual information was provided (value 1); not intelligible based on visual input only (value 0). a Several of the signs in the recording sessions were not accompanied by speech.

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Fig. 3. Comparison of intelligibility of sign, speech, and combination of both in S1 and S2. The vertical axis represents how often (as a percentage of total) a sign, a spoken utterance or the combination was given value 2 (i.e. was considered to be intelligible).

analyzer who may have become accustomed to particular patterns of signing and speech in a given subject, thus gaining a better understanding of their communication over time. As in all face-to-face communication, context was found to be important. This included the intelligibility of combined speech-sign communication. When values 2 (clearly intelligible with no contextual information) and 1 (intelligible in context) were combined, overall intelligibility for combined speech and sign in subject S1 was as high as 92% while S2 scored 81%. 3.5. Relationship between phone inventory size and sign accuracy From Tables 3 and 4 we see that S1 has more than twice as many consonant phones than S2. S1 also used a greater repertoire of handshapes than S2 and showed less deviancy in handshape production, movement and place of articulation than S2 (Tables 5 and 6). S1 also scored better on intelligibility for both speech and sign when analyzed separately and for the speech-sign combination. The subject with the larger inventory of phones had more correctly produced signs. 3.6. Other observations In addition to analyzing handshape repertoires and intelligibility, several other general observations were made during the analysis. Firstly, these concerned movement production during signing:  S1 seemed to produce more accurate movements when these were produced in relation to a surface (e.g. her body, a table).  S1 had a tendency to repeat a movement several times after the first production of the sign.10  At times, S1 dispensed with movement during signing.  S2 often supported her hands on the table, reducing her capacity for movements. Secondly, the following observations were made regarding speech-sign combinations:  For S2, on several instances the spoken word and the sign were not produced simultaneously. In general this was as a sequence: first the spoken word, then the sign.  S2 showed more sign and speech combinations at the beginning than towards the end of the recording session. 10

Although reduplication is a common construction in Norwegian Sign Language it occurs only on verbs. Since the data for the present study excluded verbs the repetition of movement in the signs produced by S1 in the data could not be due to reduplication.

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Fig. 4. Handshape clusters for S1. Handshapes from Fig. 1 are arranged using closeness to mark frequency of replacement in relation to another handshape. The size of a handshape reflects he frequency of its production, the bigger in size the more frequent produced in our data. Handshapes which functioned most often as replacements for other handshapes are circled.

Finally, we made the following observations regarding two-handed signs:    

Both subjects showed a tendency in two-handed signs towards a simpler handshape on the non-dominant hand. Both subjects switched dominant and non-dominant hand throughout the recording. Both subjects produced two-handed signs as one-handed signs. One difference in the use of signing between the subjects was that S1 produced two-handed signs far more frequently than S2, resulting in a much higher number of handshape tokens for S1.

4. Discussion We have studied two Norwegian subjects with Cri du chat syndrome (CCS), an inherited condition affecting speech and communication. Both subjects are speech impaired and employ a combination of manual signs and speech (SSN) to communicate. We investigated their accuracy of handshape in the signed part, and compared intelligibility when signing and speech were assessed separately and when speech and signing were combined. Subjects were prompted to communicate the content of pictures of common objects and concepts. The outcome was recorded on video and assessed by an independent observer. Accuracy of handshapes in signing was measured by comparison with recognized targets from the sign supported Norwegian (SSN) encompassing signs adopted from the standard Norwegian Sign Language (NTS), and included established subject-specific signs. Our analysis revealed that both subjects produced handshapes deviant from the target handshapes, which is in accordance with findings from studies on autistic children (Seal & Bonvillian, 1997). Deviancy from target occurred also in several other signing parameters including movement, place of articulation and hand orientation, but this was not investigated systematically. However, we made several observations similar to findings from studies on autistic children (Seal & Bonvillian, 1997), e.g. simplification of two-hand sign in both movements and handshapes, larger movement in general, and tendency to produce movements with contact, as well as studies in early sign language acquisition (Morgan et al., 2007), e.g. reduplication of movement. Subject S1 showed less deviancy than S2 in both handshape and overall sign production. S1 also has a larger phone inventory than S2. Since delayed motor development is a known issue in CCS (Carlin, 1990) we propose that deficient motor control underlies the deviance of in signing in both subjects; this proposal is developed further below. The overall repertoire of handshape production by both S1 and S2 can be described as clusters of handshapes, where lesser-used handshapes group around a core of 4–5 frequently produced handshapes. These most frequent handshapes correlate with the so called basic handshapes in signed languages (Battison, 1978); this may support our contention

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Fig. 5. Handshape clusters for S2. See legend for Fig. 4.

Fig. 6. Basic handshapes in signed languages.

that impaired motor control underlies articulatory deviancy in CCS. We also noted that one target handshape was often replaced by another handshape token, even though the target token was correctly produced by the subject on other occasions. This is illustrated in Figs. 4 and 5 where (a) handshapes are arranged so that they are placed close to the handshape(s) that commonly replaces them, and (b) the sizes of the different handshapes reflect the frequency of their production. The more frequently a handshape occurred in the data the larger its representation in the figure. The most frequently produced handshapes are therefore represented as the largest handshapes while being surrounded by less frequently produced handshapes which they often replaced. In both figures, handshapes which functioned most often as replacements for other handshapes are circled. The clustering of handshapes depicted in Fig. 4 can be explained by similarity of handshape features. We suggest that if motor control is a factor in handshape deviancy for the subjects, then similar handshapes will have a higher probability of replacing each other. Our data provide another important indication that impaired motor control is a factor underlying handshape deviancy in these subjects. In both S1 and in S2, the most frequently produced handshapes, including those which also most frequently functioned as replacement handshapes, coincided with the 6 basic handshapes for signed languages as proposed by Battison (1978) and Boyes Braem (1990a, 1990b) (see Fig. 6) based on research on American Sign Language and other western signed languages. The criteria for according special status to these handshapes are as follows (Battison, 1978):  They are the most frequent handshapes in a given signed language.  They are usually acquired earlier by children than the other handshapes.  They are found in all described signed languages.

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 In two-handed signs the handshape on non-dominant hand is conventionally the same handshape as the dominant hand, otherwise it is required to be one of the basic handshapes. These findings have been confirmed by other researchers working on non-western signed languages (Zeshan, 2000). Because basic handshapes by definition occur more frequently in signs than non-basic handshapes, the higher frequency of these handshapes in our data is not surprising while supporting the notion that these basic handshapes are an integral component of Norwegian Sign Language and thus the manual parts of SSN. There is, however, another outcome of our study that requires an explanation, which might point in the direction of motor control as a factor: the tendency for both subjects to replace non-basic target handshapes with basic handshapes or handshapes close to basic handshapes in form. This suggestion is supported by findings from a study in early sign language acquisition (Morgan et al., 2007). To account for this we suggest that basic handshapes are motorically relatively easy to produce and also visually distinct from each other. This is also suggested by other studies. For example, Boyes Braem (1990a, 1990b) proposes that across signed languages, patterns of handshape development could be predicted by phonological complexity of the sign leading to higher motor control demands in the production of the sign, as well as the availability of visual and tactile feedback during production. Morgan et al. (2007, p. 4) draw a distinction between marked and unmarked segments, where the term unmarked refers to segments being ‘‘phonetically and phonologically simple, and are the most frequently occurring in the language’’. Thus, in a sign different handshapes will contain different numbers of features determining the markedness of particular handshapes. As a consequence Morgan et al. (2007, p. 4) argue that ‘‘marked handshapes are more phonologically complex than unmarked [. . .], as well as being motorically more difficult’’. Furthermore, the most unmarked handshapes seem be most frequent in the lexicons of the world’s different sign languages. Six of these unmarked handshapes have been identified as basic handshapes. As a consequence basic handshapes can be expected to occur with higher frequency in many signed languages. It has in fact been proposed that there is a correlation between frequency of occurrence and ease of articulation, as revealed by analysis of Taiwan Sign Language and American Sign Language (Ann, 1996). The relatively frequent use of basic handshapes and ease of production may explain the appearance of basic handshapes in signed language in general and their appearance as the most frequent replacement handshapes in our data. If motor problems influences sign production in S1 and S2 one might expect that handshapes that are easy to articulate will tend to replace target handshapes which are more difficult to produce. This is supported by observations from studies on small children acquiring a signed language, who also tend to replace marked handshapes with unmarked handshapes, in particular basic handshapes, in their signing (e.g. Morgan et al., 2007; Siedlecki & Bonvillian, 1993). Siedlecki and Bonvillian (1993) found that five of the basic handshapes accounted for nearly all of the children’s handshape substitutions for marked handshapes. Another important observation is that both subjects show a relatively high degree of handshape consistency in response to a particular stimulus. The deviancy from the target handshape, however, was not the same for all signs. A handshape target produced with deviancy in one sign was sometimes produced correctly in a different sign. Thus the consistency in handshape deviancy regards the production of handshapes in tokens for the same sign, but not necessarily in tokens for a different sign. To explain this phenomenon it is likely that other factors, including the movement complexity of the target sign and two-handedness, must be taken into account. The present analysis does not address this possibility; further research will be needed to investigate the influence of different signing parameters on deviancy in sign production in children with CSS. There is, however, additional support for the hypothesis that motor control difficulties might play a role in sign deviancy in CSS. Since place of articulation was reported as being produced correctly already at an early age by children acquiring a signed language, the errors in place of articulation produced by our subjects, who both were significantly older at the time of recording and who had been learning SSN for several years, can be interpreted as deviancy from typical sign production as well as early sign acquisition in children aged 13–18 months. This deviancy could be interpreted as being caused by amongst other things motor control difficulties. Other factors, like the reduplication of movements by our subjects, support this interpretation (see Morgan et al., 2007, for a discussion on the relation between reduplication of movements in signing and motor control development). However, without any further information on the level of apraxia and other motor issues a direct conclusion cannot be drawn, as also Seal and Bonvillian (1997) point out in their study regarding the use of signs in autistic children. It

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seems, however, that SSC in CCS and autistic children share some of the same qualities in deviance from signing produced by native signers. Future comparative studies of SSC in children suffering from CCS and autistic children might be useful to shed more light on this issue and on the question on apraxia and motor issues. We also found that, in both subjects, the combination of speech and sign significantly improved intelligibility compared with the isolated production of either, including the sum of scores for both isolated productions. This result indicates that the intuitive understanding of the positive effect of sign supported Norwegian (SSN) for individuals with CCS by the teachers of S1 and S2 might be correct. In informal discussions with 3 of the teachers using SSN with the subjects they mentioned their feeling that the separate communication channels, visual and auditive, complement each other with regard to intelligibility. There are two potential explanations for this synergy between speech and sign. One, the consistency in deviancy of single signs/words is likely to lead to familiarization in communication partners, increasing intelligibility. Even so, intelligibility was significantly reduced when sign and speech were separately presented, probably reflecting deviancy from the target. Secondly, when sign and speech are produced together the interaction between word and sign narrows down the range of possible targets of reference. This occurs even if production of each is impaired and there is a high degree of deviancy from the target. This is amply illustrated by an example where the combination of sign and speech failed to be intelligible. In recording session 1 subject S1 spoke about her cat sleeping in a particular place. The word she tried to produce was SEKK ‘backpack’, which auditively is close to the word SENG ‘bed’. The sign SENG has a high degree of visual similarity to the sign SEKK thus, in view of word similarity, the teacher had difficulties understanding whether S1 was referring to her bed or her backpack. This is an unusual case where both visual and auditive similarity, combined with deviancy of production, constrained intelligibility. In the great majority of cases, however, words and signs will differ significantly in either visual or auditive modes, thus allowing the sign-speech combination to become intelligible even if the production of both parts is poor. To our knowledge this is the first study of deviancy of handshape and intelligibility of signs (in isolation and in combination) in subjects with Cri du chat Syndrome. However, our analysis has been solely based on qualitative methods of assessment and, for this reason, methodological concerns need to be addressed. First, our conclusions concerning intelligibility are restricted to two individual subjects in a specific methodological setting. Further research will be needed to confirm our observations using a larger corpus and with independent subjects. We also suggest that the methods used for the evaluation of intelligibility warrant further refinement. In addition, we stress that the evaluation of intelligibility was performed by a single investigator. This was due to the relative rarity of trained sign researchers with experience of phonetic analysis. Finally, target handshapes were unevenly distributed in the stimuli material. This may affect the outcome in terms of production frequency, and in turn may weaken the argument that replacement handshapes correlate with basic handshapes due to ease of production. We recommend that future studies should employ a test battery with evenly distributed handshapes and with different degrees of movement. 5. Conclusion The present study has revealed that the different components of the sign supported Norwegian used for communication by 2 subjects with Cri du chat Syndrome (CCS) can markedly affect overall intelligibility. We report that the combination of sign and speech is significantly more intelligible than either part alone. Increased intelligibility may be partly ascribed to a high degree of consistency in the deviance of manual parameter production in a sign, like the handshape, and speech, leading to familiarization by the communication partner and facilitating interpretation. We also report that basic handshapes occur more often as replacements for target handshapes than non-basic handshapes. This may be explained by a lower degree of production difficulty for these basic shapes as compared to non-basic handshapes. If further studies should confirm this tendency we would recommend that the sign inventory of the SSN is reevaluated to take into account the different levels of difficulty of each handshapes, in both one-handed and two-handed signs, a recommendation also made by Seal and Bonvillian (1997) for autistic children. This study provides a starting point for descriptions of how sign supported communication such as sign supported Norwegian can be used to facilitate communication in individuals with CCS, and further outlines methods for the evaluation of communication skills in such speech-impaired subjects.

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Appendix A See Tables A1 and A2. Table A1 List of produced signs for S1 in order of appearance. Recording session 1

Recording session 2

SIGN

Translation

SIGN

Translation

BANAN BANAN GUL RØD BUKSE ˚ BLA ? VOGN GUL HEST MARIA JAKKE ROSA GRØNN GUL LILLA RØD GRØNN KNIV MAT LAMPE ˚ NE MA SOL OPPE TAK PEK BAMSE BRUN GRØNN SYKKEL DUKKE TV MELK PENGER FEMTI EGG FIRE Mandag TIRSDAG ONSDAG Torsdag FREDAG LØRDAG PÆRE APPELSIN EPLE GRØNN NØKKEL HJEMME Klokke HJEMME DØR KJØKKEN OPPE

Banana Banana Yellow Red Trousers Blue Wagon Yellow horse Maria (name) Jacket Pink Green Yellow Purple Red Green Knife Food Lamp Moon Sun Up on the ceiling Teddy bear Brown Green Bicycle Doll TV Milk Money Fifty Egg Four Monday Tuesday Wednesday Thursday Friday Saturday Pear Orange Apple Green Key Home Watch/clock (At) home Door Kitchen Up

JORD RUNDT ˚ NE MA SOL STJERNE JANUAR FEBRUAR MARS APRIL MAI JUNI JULI AUGUST SEPTEMBER OKTOBER November Desember RØD GRØNN GUL GUL RØD ˚ BLA ORANSJE SKO STØVEL SKO/Støvel SOKKER JORD RUNDT ˚ NE MA SOL SOL STJERNE JANUAR FEBRUAR MARS APRIL MAI JUNI JULI AUGUST SEPTEMBER OKTOBER NOVEMBER DESEMBER GRØNN GUL RØD ORANSJE ˚ BLA

Earth Round Moon Sun Star January February March April May June July (used the sign for hot) August September Oktober November December Red Green Yellow (not NSL sign) Yellow (not NSL sign) Red Blue Orange (same as yellow) Shoe Boot (same as shoe) Shoe/boot Socks (same as sko) Earth Round Moon Sun Sun Star January February March April May June July (used the sign for hot) August September October November December Green Yellow (not NTS sign) Red Orange (same as yellow) Blue

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Table A1 (Continued ) Recording session 1

Recording session 2

SIGN

Translation

SIGN

Translation

IKKE ? SVART USA BILDE SMØR BRØD STØVEL HJEMME GRØNN SKI HJEMME LEKE FOTBALL1 FOTBALL2 SOKKER PARAPLY ˚ BLA REGN BUKSE GITAR STRYKE(JERN) SAG SAFT HAMMER HAMMERLILLE B LILLEHAMMER B SAFT LITE TOM DUSJ KATT(er) M F F ˚ ND HA TI DAGER ˚ GRA HVIT SVART SEKK(EN) SKOLE SOVE SKOLE ˚ OPP PA ? F ? USA ONSDAG ˚R I GA M T ˚ NED(EN) MA ˚ R(ET) A

Not ?– Black USA Picture Butter Bread Boot (At) home Green Ski (At) home Play Soccer 1 Soccer 2 Socks Umbrella Blue Rain Trousers Guitar Iron Saw Juice Hammer Name of city B Name of city B Juice Little Empty Shower Cat M F F Hand (referring to a cat’s paw) Ten Days Grey White Black Backpack School Sleep School Up onto ? F ? USA Wednesday Yesterday M T Month Year

SKO STØVEL SOKKER

Shoe Boot (same as shoe) Socks (same as sko)

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Table A1 (Continued ) Recording session 1

Recording session 2

SIGN

Translation

TALL DATO FEMTEN JUNI TOTUSENSYV HELGA BY(EN) ? T-BANE FILM TELLE I DAG FEM NED

Number Date Fifteen June Two thousand and seven Weekend City ? Subway Movie Count Today Five Down

SIGN

Translation

Table A2 List of produced signs for S2 in order of appearance. Recording session 1

Recording session 2

SIGN

Translation

SIGN

Translation

STØVEL TO TO IKKE REGN(E) SOKKER MANGE ROSA BRILLER ˚ BLA ROSA SAFT DRUER BRØD BANANER PØLSE PØLSE FIRE IS MANGE FIRE GAFFEL KNIV MELK KLOKKE EN RØD

Boot Two Two Not (To) rain Socks Many Pink Glasses Blue Pink Juice Grapes Bread Bananas Sausage Sausage Four Ice Many Four Fork Knife Milk Watch/clock One Red

JANUAR FEBRUAR MARS APRIL MAI JUNI JULI AUGUST SEPTEMBER OKTOBER OKTOBER NOVEMBER DESEMBER JANUAR FEBRUAR MARS APRIL MAI MAI JUNI JULI AUGUST SEPTEMBER OKTOBER NOVEMBER DESEMBER 2006

January February March April May June July (sign for hot) August September October October November December January February March April May May June July (sign for hot) August September October November December 2006

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Table A2 (Continued ) Recording session 1

Recording session 2

SIGN

Translation

SIGN

Translation

HVIT SVART TRE BAMSE TO BIL RØD BOK HJELM SYKKEL SVART SYNGE MANGE VINDU NØKKEL DØR(A) TELEFON A AND FAR RØD VANN ˚T BA FIN SKJERF PYNT(E) VESKE VESKE RØD GUTT T ˚ BLA RØD FUGL BLOMST(ER) MANG FIN BLOMST FLAGG NORSKE FLAGG SPISE IS SEKK BØTTE TV SVØMME SKI IKKE VARM POLITI AND FUGL AND HUND SE JEG SE

White Black Three Teddy bear Two Car Red Book Helmet Bicycle Black Sing Many Window Key Door Telephone A Duck Father Red Water (not a NTS sign, but was used by the teacher as well) Boat Fine/nice Scarf Adjourn(ment) Handbag Handbag Red Boy T Blue Red Bird Flower Many Fine/nice Flower Flag Norwegian Flag Eat Ice Backpack Bucket TV Swim Ski Not Warm/hot Police (not a NTS sign) Duck Bird Duck Dog Look I Look

SOL MONTH ˚ NE MA STJERNE STJERNE

Sun Month Moon Star Star

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Table A2 (Continued ) Recording session 1

Recording session 2

SIGN

Translation

AND SPISE JEG SPISE KAKE SPISE BANAN JEG TE KAKAO

Duck Eat I Eat Cake Eat Bananas I Tea Cocoa

SIGN

Translation

Appendix B. Continuing education questions 1. What is NOT a difference between sign supported communication and a natural signed language? 1. Inflection 2. A grammar independent from the spoken language 3. Use of content words (=signs) 4. Use of functional words (=signs) 2. How are language skills in individuals with cri du chat affected by the syndrome? 1. No at all 2. All aspects of speech and spoken language development are delayed 3. Speech perception is delayed 4. Speech production is delayed 3. Which parameters of a sign are used in SSN? 1. Only the non-manual parameters 2. All of it 3. Only the manual parameters 4. The manual parameters and mouthing 4. Which sign parameter is best described through phonetic/phonological analysis of sign languages? 1. Handshape 2. Movement 3. Place articulation 4. Eye gaze 5. When did the highest intelligibility occur in the participants? 1. When only signs were used 2. When only speech was used 3. When a combination of signs and speech was used 4. There were no differences

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