SL disorders and atypical signers Flashcards
(24 cards)
List development conditions for hearing signers
Landau-Keffner syndrome, downs syndrome
List developmental conditions for deaf signers
SLI, Williams syndrome, Autism
Acquired conditions for signers
Stroke, schizoprhenia, parkinsons, cerebrella ataxia
Atkinson (2006)
Voice- hallucinations in scz; Insight into subvocal thought and sensory feedback loops; suggesting a failure in subvocal articulation processes- influenced by both auditory deprivation and language modality
- same reports of vividness in hearing
- feed forward models- expected sensory feedback underpins this subvocal motor acts (mirror neurones)
- few people are born profoundly deaf so may explain mixed perception of voices and auditory hallucinations
Frith 1992
subvocal thought hypothesis; failure in self monitoring subvocal thought and misinterpreting it as external
Williams syndrome study
Deaf case with WS (Heather); errors consistent with spoken lang deficits in WS (spatial relationships and classifier grammar); low IQ but much better at language than peers
Atkinson et al 2002
Woll 2012: subtle lang diffs in spoken, much more transparent in bsl
Woll and Grove 1996
Ruthie and Sallie 1996- hearing twins of deaf parents- verbal skills more advance than non verbal, bsl much better than english– motor skills? confounded by parents?
Showed evidence of a dissociation between lexical and morphosyntactic ability in both modalities. This indicates that, despite its early benefits, signing is not a solution for children with Down syndrome, and that the particular difficulties in the areas of morphology and syntax may have a deeper basis.
Down syndrome
severe delay in language acquisition, onto adulthood with morphology and syntax, sign language has been shown to facilitate language earlier as an AAC
Kouri (1989)
Children who have failed to develop spoken language will learn extensive sign vocabularies,
- case-study of a young child over 8m period of sign and speech intervention, developed a vocabulary of 1,643 signed and/or spoken words.
Sieratski 2001
Landau-kleffner syndrome (auditory agnosia developmental disorder- lose hearing from epilepsy-
case study, glbal aphasia in english - learnt BSL at 13; able to speak but low reading and grammar
– impairment did not affect acq of sign
Deona 2011
LKS- SL as an alternative to oral communication is increasingly accepted, need to maintain communication improves outcomes for affected children. Some fear learning SL may delay or impoverish relearning english but this is not supported- may FACILITATE recovery by stimulating cortical language networks
Mason 2010
SLI found in 13 deaf children; proves it is not a deficit with auditory processing. in English affects multi-syllabic words/phonology, in deaf children affects specific complex morphological markings instead of phonology
SLI research
Recent area of study- not enough tests or clinicians to adequately investigate, often overlooked in deaf children. need more studies and tests to be able to intervene for these children as hearing children are.
Autism characteristics that make sign different?
impaired social interaction, stereotyped behaviour/movement, lack eye contact (Swettenham 98), difficulty reading emotion, ToM (Baren-cohen 93/03), face processing (Langdell 78)
The prevalence of ASD is higher in deaf people than in hearing people. However, conditions that mimic ASD associated with language deprivation are even higher (Wright and Oakes, 2012).
Shield and Meyer 2012
ASD deaf signers make erorrs in palm orientation, movement and location– failure of self-other mapping. Indicates mirror orientation, not thinking of how others would perceive the sign
Rogers and Pennington 1991
Support mirroring hypothesis- should sign outwards but dont
Denmark PHD (2011)
deaf & hearing children with ASD; no general face processing deficit for communication in deaf- SL reduces/protects from this impairment.
- Hearing impairments in facial expression for adverbials inferring mental state, but no general deficit in SL; need to change diagnostic criteria or interventions for them!
Morgan 2006 / smith 2010
ASD language savant christopher- struggled to learn BSL; esp. classifiers and space/location– shows comparison of acquisition mechanisms for L1/L2 and modality
aphasia
interesting to see commonalities of damage to language processing for modailties – generally shows consistent deficits for area damage
Hickock 1996/98
96: paraphasic errors in LHD signers, not RHD
98: anomia is very common in sign as in spoken- show same organisation of brain
Poizner 1987
congenitally deaf sgners after stroke: consistent deficits in perception for wernickes aphasia for sp and sign; differece in temporal signers though
poizner and Kegl 1992
gestures not impaired where signs were with aphasia– separate modality (ASL)
Tyrone 2009
Cerebellar ataxia: speech and sign requires coordination of multiple articulators simultaneously.
Notably, sign production deficits broadly resembled ataxic dysarthria, while non-linguistic movement deficits were similar to those previously reported for ataxic limb movement. (case study)
- so same articulators affected differenty (better for non-lingusitic)
Tyrone 1999
Parkinsons have deficits in motor control; assessed free conversation compared to controls: frequent error patters from attempts to reduce motor demands and difficulty coordinating movements of independent articulators
1) Segmentation (hold unit in sequence for longer)
2) blending (adjacent segments)
3) featural unravelling (broke down to component features)
