Using Virtual Reality to investigate multitasking ability in individuals with frontal lobe lesions.

Individuals with lesions in the prefrontal cortex often show impairments with the organisation of their behaviour in everyday life. These difficulties can be hard to detect using structured formal tests. The objective of this study was to use Virtual Reality (VR) to explore the multitasking performance of individuals with focal frontal lobe lesions, specifically using the Jansari assessment of Executive Functions (JEF©). Nineteen individuals with frontal lobe lesions were compared with 19 matched controls on the test and a group of commonly used clinical measures of neuropsychological functioning, as well as questionnaire measures of everyday activity, anxiety and depression. There was a significant difference between groups on the overall JEF© score and on five of the eight individual constructs, namely the planning, creative thinking, adaptive thinking, event-based Prospective Memory (PM) and time-based PM constructs. There were no differences between groups on the non-VR EF individual measures apart from on one EF control measure, Trail Making A. These results demonstrate the potential clinical utility of the JEF© and highlight the value of ecologically valid VR measures in detecting impairments in EF in individuals with frontal lobe lesions.

Signing with the Face: Emotional Expression in Narrative Production in Deaf Children with Autism Spectrum Disorder.

This study examined facial expressions produced during a British Sign Language (BSL) narrative task (Herman et al., International Journal of Language and Communication Disorders 49(3):343-353, 2014) by typically developing deaf children and deaf children with autism spectrum disorder. The children produced BSL versions of a video story in which two children are seen to enact a language-free scenario where one tricks the other. This task encourages elicitation of facial acts signalling intention and emotion, since the protagonists showed a range of such expressions during the events portrayed. Results showed that typically developing deaf children produced facial expressions which closely aligned with native adult signers' BSL narrative versions of the task. Children with ASD produced fewer targeted expressions and showed qualitative differences in the facial actions that they produced.

Nonverbal Executive Function is Mediated by Language: A Study of Deaf and Hearing Children.

Studies have suggested that language and executive function (EF) are strongly associated. Indeed, the two are difficult to separate, and it is particularly difficult to determine whether one skill is more dependent on the other. Deafness provides a unique opportunity to disentangle these skills because in this case, language difficulties have a sensory not cognitive basis. In this study, deaf (n = 108) and hearing (n = 125) children (age 8 years) were assessed on language and a wide range of nonverbal EF tasks. Deaf children performed significantly less well on EF tasks, even controlling for nonverbal intelligence and speed of processing. Language mediated EF skill, but the reverse pattern was not evident. Findings suggest that language is key to EF performance rather than vice versa.

Detecting Memory Impairment in Deaf People: A New Test of Verbal Learning and Memory in British Sign Language.

OBJECTIVE: Most existing tests of memory and verbal learning in adults were created for spoken languages, and are unsuitable for assessing deaf people who rely on signed languages. In response to this need for sign language measures, the British Sign Language Verbal Learning and Memory Test (BSL-VLMT) was developed. It follows the format of the English language Hopkins Verbal Learning Test Revised, using standardized video-presentation with novel stimuli and instructions wholly in British Sign Language, and no English language requirement. METHOD: Data were collected from 223 cognitively healthy deaf signers aged 50-89 and 12 deaf patients diagnosed with dementia. Normative data percentiles were derived for clinical use, and receiver-operating characteristic curves computed to explore the clinical potential and diagnostic sensitivity and specificity. RESULTS: The test showed good discrimination between the normative and clinical samples, providing preliminary evidence of clinical utility for identifying learning and memory impairment in older deaf signers with neurodegeneration. CONCLUSIONS: This innovative video testing approach transforms the ability to accurately detect memory impairments in deaf people and avoids the problems of using interpreters, with international potential for adapting similar tests into other signed languages.

Detecting Cognitive Impairment and Dementia in Deaf People: The British Sign Language Cognitive Screening Test.

To provide accurate diagnostic screening of deaf people who use signed communication, cognitive tests must be devised in signed languages with normative deaf samples. This article describes the development of the first screening test for the detection of cognitive impairment and dementia in deaf signers. The British Sign Language Cognitive Screening Test uses standardized video administration to screen cognition using signed, rather than spoken or written, instructions and a large norm-referenced sample of 226 deaf older people. Percentiles are provided for clinical comparison. The tests showed good reliability, content validity, and correlation with age, intellectual ability, and education. Clinical discrimination was shown between the normative sample and 14 deaf patients with dementia. This innovative testing approach transforms the ability to detect dementia in deaf people, avoids the difficulties of using an interpreter, and enables culturally and linguistically sensitive assessment of deaf signers, with international potential for adaptation into other signed languages.

Deaf children's non-verbal working memory is impacted by their language experience.

Several recent studies have suggested that deaf children perform more poorly on working memory tasks compared to hearing children, but these studies have not been able to determine whether this poorer performance arises directly from deafness itself or from deaf children's reduced language exposure. The issue remains unresolved because findings come mostly from (1) tasks that are verbal as opposed to non-verbal, and (2) involve deaf children who use spoken communication and therefore may have experienced impoverished input and delayed language acquisition. This is in contrast to deaf children who have been exposed to a sign language since birth from Deaf parents (and who therefore have native language-learning opportunities within a normal developmental timeframe for language acquisition). A more direct, and therefore stronger, test of the hypothesis that the type and quality of language exposure impact working memory is to use measures of non-verbal working memory (NVWM) and to compare hearing children with two groups of deaf signing children: those who have had native exposure to a sign language, and those who have experienced delayed acquisition and reduced quality of language input compared to their native-signing peers. In this study we investigated the relationship between NVWM and language in three groups aged 6-11 years: hearing children (n = 28), deaf children who were native users of British Sign Language (BSL; n = 8), and deaf children who used BSL but who were not native signers (n = 19). We administered a battery of non-verbal reasoning, NVWM, and language tasks. We examined whether the groups differed on NVWM scores, and whether scores on language tasks predicted scores on NVWM tasks. For the two executive-loaded NVWM tasks included in our battery, the non-native signers performed less accurately than the native signer and hearing groups (who did not differ from one another). Multiple regression analysis revealed that scores on the vocabulary measure predicted scores on those two executive-loaded NVWM tasks (with age and non-verbal reasoning partialled out). Our results suggest that whatever the language modality-spoken or signed-rich language experience from birth, and the good language skills that result from this early age of acquisition, play a critical role in the development of NVWM and in performance on NVWM tasks.

How do typically developing deaf children and deaf children with autism spectrum disorder use the face when comprehending emotional facial expressions in British sign language?

Facial expressions in sign language carry a variety of communicative features. While emotion can modulate a spoken utterance through changes in intonation, duration and intensity, in sign language specific facial expressions presented concurrently with a manual sign perform this function. When deaf adult signers cannot see facial features, their ability to judge emotion in a signed utterance is impaired (Reilly et al. in Sign Lang Stud 75:113-118, 1992). We examined the role of the face in the comprehension of emotion in sign language in a group of typically developing (TD) deaf children and in a group of deaf children with autism spectrum disorder (ASD). We replicated Reilly et al.'s (Sign Lang Stud 75:113-118, 1992) adult results in the TD deaf signing children, confirming the importance of the face in understanding emotion in sign language. The ASD group performed more poorly on the emotion recognition task than the TD children. The deaf children with ASD showed a deficit in emotion recognition during sign language processing analogous to the deficit in vocal emotion recognition that has been observed in hearing children with ASD.

The British Sign Language (BSL) norms for age of acquisition, familiarity, and iconicity.

Research on signed languages offers the opportunity to address many important questions about language that it may not be possible to address via studies of spoken languages alone. Many such studies, however, are inherently limited, because there exist hardly any norms for lexical variables that have appeared to play important roles in spoken language processing. Here, we present a set of norms for age of acquisition, familiarity, and iconicity for 300 British Sign Language (BSL) signs, as rated by deaf signers, in the hope that they may prove useful to other researchers studying BSL and other signed languages. These norms may be downloaded from www.psychonomic.org/archive.