Blog Archives

Morphometric Differences in the Heschl’s Gyrus of Hearing Impaired and Normal Hearing Infants

This study investigates the morphometry of Heschl’s gyrus and its included primary auditory cortex (PAC) in hearing impaired (HI) and normal hearing (NH) infants. Fourty-two infants, age 8–19 months, with NH (n = 26) or hearing impairment (n = 16) were studied using high-resolution 3D magnetic resonance imaging. Gray matter (GM) and white matter (WM) volumes were obtained using software for automatic brain imaging segmentation to estimate the volume of each tissue within manually defined regions for the anterior portion of Heschl’s gyrus (aHG) in each individual subject, transformed to an infant brain template space. Interactions among group (HI, NH), tissue type (GM, WM), and hemisphere (left, right) were examined using analysis of variance. Whole-brain voxel-based morphometry was utilized to explore volume differences between groups across the entire brain. The HI group showed increased GM and decreased WM in aHG compared with the NH group; likely effects of auditory deprivation. The HI group did not exhibit their typical L > R asymmetry pattern that the NH group showed. Increased GM in aHG in HI infants may represent abnormal cortical development in PAC as seen in animal models of sensory deprivation. Lower WM volume is consistent with studies with deaf adults.

from Cerebral Cortex

Advertisements

Executive functioning and the impact of a hearing loss: Performance-based measures and the Behavior Rating Inventory of Executive Function (BRIEF)

The impact of deafness on a child’s rated executive functioning behaviors and performance capabilities on neurological, cognitive, and achievement domains were examined in a sample of 22 deaf students (ages 5 to 18). The parent and teacher ratings on the Behavior Rating Inventory of Executive Function (BRIEF) showed significant positive correlations (p < .01) on six of the eight clinical scales. There were significant correlations between the BRIEF reports and the students' scores on the Wisconsin Card Sorting Test, the (Children's) Color Trails Test, and the Woodcock-Johnson: Writing Fluency subtest. The Wisconsin Card Sorting Test: Total Errors scale and the Writing Fluency subtest accounted for 70% variance of the parent BRIEF Global Executive Composite and 65% of the variance for the teacher report on this same composite scale. Students with genetic deafness were rated with significantly less challenges with executive functioning (p < .05) on BRIEF scales and performed significantly better on select student measures than students with other causes of deafness.

from Child Neuropsychology

Spatial and numerical abilities without a complete natural language

We studied the cognitive abilities of a 13-year-old deaf child, deprived of most linguistic input from late infancy, in a battery of tests designed to reveal the nature of numerical and geometrical abilities in the absence of a full linguistic system. Tests revealed widespread proficiency in basic symbolic and non-symbolic numerical computations involving the use of both exact and approximate numbers. Tests of spatial and geometrical abilities revealed an interesting patchwork of age-typical strengths and localized deficits. In particular, the child performed extremely well on navigation tasks involving geometrical or landmark information presented in isolation, but very poorly on otherwise similar tasks that required the combination of the two types of spatial information. Tests of number- and space-specific language revealed proficiency in the use of number words and deficits in the use of spatial terms. This case suggests that a full linguistic system is not necessary to reap the benefits of linguistic vocabulary on basic numerical tasks. Furthermore, it suggests that language plays an important role in the combination of mental representations of space.

from Neuropsychologia

When deaf signers read English: Do written words activate their sign translations?

Deaf bilinguals for whom American Sign Language (ASL) is the first language and English is the second language judged the semantic relatedness of word pairs in English. Critically, a subset of both the semantically related and unrelated word pairs were selected such that the translations of the two English words also had related forms in ASL. Word pairs that were semantically related were judged more quickly when the form of the ASL translation was also similar whereas word pairs that were semantically unrelated were judged more slowly when the form of the ASL translation was similar. A control group of hearing bilinguals without any knowledge of ASL produced an entirely different pattern of results. Taken together, these results constitute the first demonstration that deaf readers activate the ASL translations of written words under conditions in which the translation is neither present perceptually nor required to perform the task.

from Cognition

Genetic predisposition and sensory experience in language development: Evidence from cochlear-implanted children

Recent neurobiological studies have advanced the hypothesis that language development is not continuously plastic but is governed by biological constraints that may be modified by experience within a particular time window. This hypothesis is tested based on spontaneous speech data from deaf cochlear-implanted (CI) children with access to linguistic stimuli at different developmental times. Language samples of nine children who received a CI between 5 and 19 months are analysed for linguistic measures representing different stages of language development. These include canonical babbling ratios, vocabulary diversity, and functional elements such as determiners. The results show that language development is positively related to the age at which children get first access to linguistic input and that later access to language is associated with a slower-than-normal language-learning rate. As such, the positive effect of early experience on the functional organisation of the brain in language processes is confirmed by behavioural performance.

from Language and Cognitive Processes

Perceptual invariance or orientation specificity in American Sign Language? Evidence from repetition priming for signs and gestures

Repetition priming has been successfully employed to examine stages of processing in a wide variety of cognitive domains including language, object recognition, and memory. This study uses a novel repetition priming paradigm in the context of a categorisation task to explore early stages in the processing of American Sign Language signs and self-grooming gestures. Specifically, we investigated the degree to which deaf signers’ and hearing nonsigners’ perception of these linguistic or nonlinguistic actions might be differentially robust to changes in perceptual viewpoint. We conjectured that to the extent that signers were accessing language-specific representations in their performance of the task, they might show more similar priming effects under different viewing conditions than hearing subjects. In essence, this would provide evidence for a visually based “lack of invariance” phenomenon. However, if the early stages of visual-action processing are similar for deaf and hearing subjects, then no such difference should be found.

from Language and Cognitive Processes

The lived experience of depression among culturally Deaf adults

Culturally Deaf adults lost hearing at early ages, communicate primarily in American Sign Language (ASL), and self-identify as culturally Deaf. Communication barriers lead to isolation, low self-esteem, abuse, and inadequate health care. Screening Deaf patients for depressive symptoms poses challenge. Nurses are rarely familiar with ASL, and depression screening tools aren’t easily translated from English to ASL. Consequently, Deaf adults are not adequately screened for depression. Qualitative interviews were conducted with culturally Deaf adults, and certified interpreters helped to enhance understanding. Text was generated from interview transcriptions and researcher observations. No novel depressive symptoms were described. Various ASL signs were used to represent depression; two participants used a unique gesture that had no meaning to others. Childhood experiences leading to depression included sexual or physical abuse, feeling ostracized from family and like a burden. Suicidal gestures communicated severity of depression. Adults felt interpreters were unwelcome during mental health encounters. No participants were asked about depressive symptoms despite frank manifestations of depression. Study describes antecedents and consequences of depressive symptoms among Deaf adults. Understanding symptom manifestations and challenges experienced by Deaf patients helps identify those at risk for depression, thereby reducing morbidity and mortality.

from the Journal of Psychiatric and Mental Health Nursing

Communicating With Australian Deaf People About Communication Technology

The paper examines deaf people’s knowledge of modern Internet communication technologies and the possible benefits they could obtain from them. We found that organisations for deaf people were active in informing their members but a very large number of people deafened by ageing were not so aware of possible benefits. Signing deaf people benefit from video communication by telephone and the Internet. Signing avatars are also of considerable benefit in making available text and voice sites on the Internet. Methods of promoting awareness for better access and suggestions for their implementation are examined.

from the Australian and New Zealand Journal of Audiology

Ocular morbidity in hearing impaired schoolchildren

Hearing impaired children are at an increased risk of having ocular morbidity. Hence, periodic eye examinations are important in deaf children.

from Child: Care, Health and Development

Cochlear implantation in children with enlarged vestibular aqueduct

Children with EVA undergoing cochlear implantation are at greater risk for CSF gushers, but they do well audiometrically and functionally. Laryngoscope, 2010

from The Laryngoscope

The role of the Nurse Specialist in the highly specialized field of Mental Health and Deafness

This opinion paper considers the need for enhanced clinical skills and knowledge to fulfil the role of a Specialist Nurse in the field of Mental Health & Deafness and informs professionals of a new group called the Mental Health & Deafness National Nurse Specialist Forum. Their knowledge and skills enable therapeutic interventions to be accessible and meaningful for Deaf people. A case study illustrates the complex nature of assessment and treatment in Mental Health & Deafness and highlights the potential devastating consequences that may occur if a Deaf person is misdiagnosed and does not access appropriate services. An increased awareness of the field and forum aims to increase the interest of nurses outside of the field and support a developing evidence base for Deaf sensitive interventions and opportunities for further pioneering work.

from the Journal of Psychiatric and Mental Health Nursing

Clinical Evaluation of the Mini-Mental State Exam with Culturally Deaf Senior Citizens

The Mini-Mental State Exam (MMSE) is commonly used to screen cognitive function in a clinical setting. The measure has been published in over 50 languages; however, the validity and reliability of the MMSE has yet to be assessed with the culturally Deaf elderly population. Participants consisted of 117 Deaf senior citizens, aged 55–89 (M = 69.44, SD = 8.55). Demographic information, including state of residence, age, and history of depression, head injury, and dementia diagnoses, were collected. A standard form of the MMSE was used with modification of test administration and stimuli including translation of English test items into a sign-based form and alteration of two items in order to make them culturally and linguistically appropriate. Significant correlations were observed between overall test score and education level (r = .23, p = .01) as well as test score and age (r = –.33, p < .001). Patterns of responses were analyzed and revealed several items that were problematic and yielded a fewer correct responses. These results indicate that clinicians need to be aware of cultural and linguistic factors associated with the deaf population that may impact test performance and clinical interpretation of test results. On the basis of these data, there is an increased risk of false positives obtained when using this measure. Further research is needed to validate the use of this measure with the culturally Deaf population.

from Archives of Clinical Neuropsychology

Two cultures, one programme: Deaf Professors as subaltern?

Deaf instructors of American Sign Language have taught ASL in formal institutions of higher learning for several decades now, yet little is known of the challenges they face within those contexts. In this study, interviews with instructors of five ASL – English Interpreter Programs (AEIP) and four Deaf Studies Programs (DSP) in Canada identified a number of common themes in particular to the intersection of culture, power, and identity. Within a post-colonial framework differences were found in the discursive practices of the participants as Deaf or non-Deaf individuals. Evidence of systemic audism experienced by the Deaf staff was noted at a number of levels, perhaps due to the existence of a Grand Narrative of Hearing and a process of Worlding based on the ideology of the hearing majority. As a result perhaps some of the Deaf instructors were ascribed or adopted the role of subaltern, where they should have instead experienced substantial social capital. Copyright © 2009 John Wiley & Sons, Ltd.

from Deafness and Education International

Use of Picture Dictionaries to Promote Functional Communication in Students With Deafness and Intellectual Disabilities

A mismatch of communication modalities can occur between students who communicate using sign language and coworkers at community-based vocational sites who do not use sign language. This study investigated the use of picture dictionaries to facilitate note writing as a form of expressive communication for students who were deaf and had mild to moderate intellectual disabilities. Students were systematically taught to use their picture dictionaries to initiate requests using the system of least prompts and the environmental arrangement strategy. A multiple baseline probe design was used. All students were able to successfully use the picture dictionaries to promote communication initiations. Implications regarding using the picture dictionaries for communication and for improving spelling of target vocabulary are discussed.

from Neuropsychologia

Bilateral progressive hearing loss and vestibular dysfunction with inner ear antibodies

Autoimmune inner ear disease (AIED) is a clinical syndrome of uncertain etiology. We present the neuro-otological findings of 2 cases of bilateral hearing loss, dizziness and the antibody profiles of the inner ears. Case 1 had bilateral progressive hearing loss, vestibular dysfunction and abnormal eye movement as the disease progressed. She had inner ear antibodies against 42 and 58 kDa protein antigency on Western blot immune assay, and responded to glycocorticosteroid but not to immunosuppressant treatment. Intratympanic steroid injection temporally eliminated her symptoms. However, she developed idiopathic Cushing’s syndrome and underwent labyrinthectomy. Case 2 became deaf as a teenager and experienced dizziness 10 years after becoming deaf. He reacted strongly to 68 kDa protein and was a good responder to immunosuppressant with steroid. As we still lack a definitive diagnostic test for AIED, careful observation of the clinical course is critical for differential diagnosis regarding the bilateral progressive hearing loss.

from Auris Nasus Larynx