| 1. |
- Henricson, Cecilia
(författare)
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Cognitive capacities and composite cognitive skills in individuals with Usher syndrome type 1 and 2
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The present thesis belongs to the research area disability research and deal with specific aspects of cognition in individuals with Usher syndrome type 1 and 2. The subject has been investigated and is discussed within an interdisciplinary framework, though the theories applied and described are derived from the area of cognitive psychology. Usher syndrome is a rare genetic condition causing a combination of visual and hearing impairment: deafblindness. There is a congenital hearing loss that is profound in type 1 and moderate to severe in type 2. During mid-childhood symptoms of visual impairment, e.g. light sensitivity, emerge and a progressive loss of visual field follows as a result of the genetically caused eye disease Retinitis Pigmentosa. The syndrome has previously been well described with respect to the genetical and medical aspects, but there has been very little research with a cognitive perspective on the population. Studies 1 and 2 in the present thesis focused on children with Usher syndrome type 1 with cochlear implants and investigated phonological skills, lexical access, working memory and reading skill in the group. Studies 3 & 4 investigated the same cognitive abilities and theory of mind in adults with Usher syndrome type 2. In study 4 the performance on theory of mind in the adults with Usher syndrome type 2 was also compared to that of another group with genetically caused deafblindness: individuals with Alström syndrome.The results were that both the children and adults with Usher syndrome had significantly poorer phonological processing than the control groups with normal hearing. There was a large variation on performance on lexical access, especially in the group of children, however several individuals performed at the same level as the control group. Reading skill was found to be at level with the control groups’. There was also great variation in performance on ToM, however the majority of individuals performed similar to the control group with normal hearing and vision. The present project has resulted in some new knowledge on cognitive performance in individuals with Usher syndrome type 1 and type 2. Performance in the participants with Usher syndrome can to a large extent can be understood by application of the models developed in previous research on populations with hearing impairment or deafness for understanding the impact of hearing with a hearing aid or cochlear implant. However, individuals with Usher syndrome experience additional difficulties in accessing information due to the progressive visual loss and the impact this has on performance is still largely unknown. Hence, the present project would recommend that interventions and support would be designed specifically to each individuals’ needs, with consideration of both the visual impairment and the hearing impairment.
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| 2. |
- Thorslund, Birgitta, 1976-
(författare)
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Effects of hearing loss on traffic safety and mobility
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aim of this PhD thesis was to investigate traffic safety and mobility for individuals with hearing loss (HL). Three studies were conducted: 1. a questionnaire survey aimed to evaluate differences in choice of transportation that might be related to HL, 2. a driving simulator study that looked into compensatory strategies and evaluated the efficiency of a tactile signal to alert the driver, and 3. a field study to evaluate these effects in real traffic and to evaluate a navigation system with a supportive tactile signal. The effects of HL discovered in this thesis add to the knowledge and understanding of the influence of HL on traffic safety and mobility. Differences found consistently point to a generally more cautious behavior. Compensatory and coping strategies associated with HL are bound to driving complexity and appear when complexity increases. These strategies include driving at lower speeds, using a more comprehensive visual search behavior and being less engaged in distracting activities. Evaluation of a tactile signal showed that by adding a tactile modality, some driver assistance systems can also be made accessible to drivers with HL. At the same time, the systems might be more effective for all users, since the driver can be more focused on the road. Based on the results in this thesis, drivers with HL cannot be considered an increased traffic safety risk, and there should be no need for adjustments of the requirements of hearing for a license to drive a car.
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| 3. |
- Frölander, Hans-Erik, 1966-
(författare)
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Deafblindness : Theory-of-mind, cognitive functioning and social network in Alström syndrome
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis addresses young adults with Alström syndrome (AS). AS causes acquired deafblindness, a severe, progressive, combined auditory and visual impairment affecting daily life and self-reliance to a degree that full participation depends on help from others and society. AS is an autosomal, recessively inherited single-gene disorder that affects the ALMS1 gene. AS has a multi-systemic pathology including a high incidence of additional multiple endocrine abnormalities, cardiomyopathy, pulmonary fibrosis, restrictive lung disease and progressive hepatic and renal failure leading to reduced life expectancy. The focus in the present thesis is on the development of Theory-of-mind (ToM) and on how ToM relates to the development of certain cognitive skills and the characteristics of the individual social network. ToM refers to the ability to understand the thoughts and feelings of others.The results reveal that individuals with AS displayed a significantly higher degree of heterogeneity in the performance of ToM tasks, and some individuals with AS performed on an equal level with nondisabled individuals. ToM performance was predicted by verbal ability and executive functioning (EF), whereas working memory capacity (WM) proved to be an indirect predictor. Later onset of visual loss further characterized AS individuals with better ToM. The sizes of the social networks of individuals with AS were smaller relative to those of nondisabled individuals, and many of the acquaintances were professionals working with individuals with AS. The number of friends correlated with ToM performance.Methods to improve verbal ability and EF, and interventions to enhance social participation in childhood of individuals with AS might prove to be fruitful. In addition assistive technology to establish and maintain friendships in adulthood is required.
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| 4. |
- Hua, Håkan
(författare)
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Employees with Aided Hearing Impairment : An Interdisciplinary Perspective
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In Sweden 13% of the general adult population (16-84 years), with or without hearing aids (HAs), report that they have difficulties following a conversation when more than two people are involved. This means that more than one million people in Sweden (9 500 000 inhabitants in total) report subjective hearing difficulties. Observations further indicate that that people with hearing impairment (HI) have an unfavorable position in the labor market. Individuals with HI report poorer health more frequently and estimate their own health to be worse than their normally-hearing peers. Increased unemployment, early health-related retirement and sick leaves are also more common for people with hearing loss compared to the population at large.The focus of the present thesis is employees with mild-moderate aided HI in the labor market. The research project had three general aims: 1) to develop knowledge about how HI interacts with cognitive abilities, and different types of work-related sound environments and workrelated tasks, 2) develop tests and assessment methods that allow for the analysis and assessment of perceived problems in clinical settings and 3) to develop knowledge that enables the possibility to provide recommendations of room acoustics and work-related tasks for employees with HI. Four studies were carried out. The studies presented in papers I-III are quantitative laboratory studies focusing on health related quality of life, cognition and effort and disturbance perceived in different types of occupational noise (daycare, office and traffic). Paper IV is a qualitative interview study aiming at exploring the conceptions of working life among employees with mild-moderate aided HI.The results from papers I-IV clearly demonstrate that noise has negative effects on employees with mild-moderate aided HI. In addition to generating significantly greater effort and disturbance, it is further reported from the participants that noise at work in combination with a HI has an impact on daily life. This includes a sense of exposure during work hours, physical and mental fatigue after work, and withdrawal from social situations in the work environment and leisure activities. None of the participants with HI performed significantly worse on the visual working tasks employed in this project compared to their normallyhearing peers. This thesis shows that employees with HI objectively perform the employed working tasks at a level similar to a well-matched normally-hearing control group. Instead, the findings of this thesis indicates that working in a noisy environment with a HI occurs at the expense of this group reporting significantly worse results on subjective measurements, including greater effort and disturbance, and lower physical health status. Interviews with these participants further confirm that these effects are indeed mostly due to noise at the workplace which could have a negative impact both physically, mentally and socially during and after work hours.The main findings of this thesis demonstrate that there is a need for extensive services for employees with HI even after a HA fitting. This thesis therefore emphasizes the importance of identifying the need for assistive listening devices, examining the room acoustics of the individual’s work setting and providing the workplace with information about the consequences of having a HI in order to facilitate communication at work. The latter is especially important as colleagues showing support and employers making adjustments at the workplace (technically or acoustically) are facilitating factors that would benefit both employees with HI and those with normal hearing. Additional research should focus on including and comparing other types of cognitive tests, work-related noises and working tasks. More research is also needed to unravel the complex area of research between factors such as cognitive processes, hearing and effort.
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| 5. |
- Socher, Michaela, 1989-
(författare)
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Reasons for Language : Language and Analogical Reasoning Ability in Children with Cochlear Implants and Children with Typical Hearing
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The usage-based model of language acquisition assumes that language is learned by its usage. General cognitive processes, especially analogical reasoning ability, are assumed to lead to the understanding of words and grammatical structures. It has been argued that the time of language or auditory deprivation children with cochlear implants (CIs) often experience early in life, might affect both their language and their cognitive abilities. Children with CIs have disadvantages in terms of language acquisition as they start receiving language input later than peers with typical hearing (TH), and the perceptual quality of the input is reduced. However, they might have additional difficulties in language acquisition if their analogical reasoning ability is negatively influenced by the language or auditory deprivation early in life. The results found in this thesis show that the language delays often seen in children with CIs are not explained by differences in analogical reasoning ability. Results indicate that analogical reasoning ability has a limited influence on language acquisition for the tested age-group. However, language abilities affect the performance on analogical reasoning tasks which are either verbal or can be supported by verbal strategies. This needs to be taken into consideration when comparing analogical reasoning ability of children with CI sand children with TH. In addition, the results from this thesis indicate that the structure of the mental lexicon is associated with the communication skills of children with CIs. The structure of the mental lexicon is most likely influenced by the amount of language input a child receives. The main implication of the results is that emphasis should be put on reducing the duration of language deprivation and to improve the quality of the language input for children with CIs.
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| 6. |
- Nakeva von Mentzer, Cecilia
(författare)
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Rethinking Sound : Computer-assisted reading intervention with a phonics approach for deaf and hard of hearing children using cochlear implants or hearing aids
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In the present thesis, computer-assisted reading intervention with a phonics approach was examined in deaf and hard of hearing children (DHH) aged 5, 6 or 7 years old using cochlear implants, hearing aids or a combination of both. Children with normal hearing (NH), matched for non-verbal intelligence and age, served as a reference group. Deaf and hard of hearing children constitute a heterogenetic population regarding cognitive and academic achievement. Many of them do not reach age appropriate levels in language and reading ability during their school years, with negative consequences for later training facilities and job opportunities. Finding relevant intervention methods to promote early language learning and literacy development that are easy to implement is therefore of great importance. In this thesis three aspects of cognitive ability (phonological processing skills, lexical access and working memory capacity), and reading ability was examined at three points in time; baseline 1, pre intervention and post intervention. Additionally, computer-assisted training delivered by means of the Internet in the children’s homes was explored in order to determine whether it would be a useful and efficient method for the DHH population. Overall, the results from the present thesis support the notion that offering a computer-assisted intervention program delivered at home, is an alternative way to support not only NH children with reading difficulties but also to support DHH children’s phonological development and decoding proficiency.
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| 7. |
- Stenbäck, Victoria
(författare)
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Speech masking speech in everyday communication : The role of inhibitory control and working memory capacity
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Age affects hearing and cognitive abilities. Older people, with and without hearing impairment (HI), exhibit difficulties in hearing speech in noise. Elderly individuals show greater difficulty in segregating target speech from distracting background noise, especially if the noise is competing speech with meaningful contents, so called informational maskers. Working memory capacity (WMC) has proven to be a crucial factor in comprehending speech in noise, especially for people with hearing loss. In auditory scenes where speech is disrupted by competing speech, high WMC has proven to facilitate the ability to segregate target speech and inhibit responses to irrelevant information. People with low WMC are more prone to be disrupted by competing speech and exhibit more difficulties in hearing target speech in complex listening environments. Furthermore, elderly individuals with a HI experience more difficulties in switching attention between wanted and irrelevant stimuli, and they employ more resources and time to attend to the stimuli than do normally - hearing (NH) younger adults.This thesis investigated the importance of inhibitory control and WMC for speech recognition in noise, and perceived listening effort. Four studies were conducted. In the first study, the aim was to develop a test of inhibitory control for verbal content, and to investigate the relation between inhibitory control and WMC, and how these two abilities related to speech recognition in noise, in young normally – hearing (YNH) individuals.In the second study we aimed to investigate the same relationship as in the first study to further strengthen the validity of the inhibitory test developed, as well as the importance of lexical access. It was also an aim to investigate the influence of age and hearing status on lexical access and WMC, and their respective roles for speech recognition in noise in both YNH and elderly HI (EHI) individuals.Study one and two showed that, for YNH, inhibitory control was related to speech recognition in noise, indicating that inhibitory control can help to predict speech recognition in noise performance. The relationship between WMC and speech recognition in noise in YNH shifted in the studies, suggesting that this relationship is multifaceted and varying. Lexical access was of little importance for YNH, although for EHI individuals, both WMC and lexical access was of importance for speech recognition in noise, suggesting that different cognitive abilities were of importance for the YNH and EHI individuals Study three investigated the relationship between inhibitory control, WMC, speech recognition in noise, and perceived listening effort, in YNH and elderly, for their age, NH, individuals (ENH). In study four the same relationships as in study three were investigated, albeit in EHI individuals. Two speech materials with different characteristics, masked with four background noises were used. The results in study three showed that less favourable SNRs were needed for informational maskers than for maskers without semantic content. ENH individuals were more susceptible to informational maskers than YNH individuals. In contrast, in study four, more favourable SNRs were needed for informational maskers. In both studies, results showed that speech recognition in noise performance differed depending on the characteristics of the speech material.The studies showed that high WMC, compared to low WMC, was beneficial for speech recognition in noise, especially for informational maskers, and resulted in lower ratings of perceived effort. Varying results were found in study three and four regarding perceived effort and inhibitory control. In study three good inhibitory control was associated with lower effort rating, while in study four, individuals with a HI and good inhibitory control rated effort as higher.The results suggest that hearing status, age, and cognitive abilities, contribute to the differences in performance between YNH, ENH, and EHI individuals in speech – recognition – in – noise - and cognitive tasks.This thesis has, for the first time, demonstrated that a measure of inhibitory control of verbal content, is related to speech recognition in noise performance in YNH, ENH and EHI individuals. Results presented in this thesis also show that both WMC and inhibitory control are related to an individuals’ perception of how effortful a listening task is. It also adds to the literature that WMC is related to speech recognition in noise performance for ENH and EHI individuals, but that this relationship is not as robust in YNH individuals.
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| 8. |
- Söderfjell, Stefan, 1970-
(författare)
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Musculoskeletal pain, memory, and aging : Cross-sectional and longitudinal findings
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The general aim of the thesis was to investigate potential differences in memory performance between participants across the adult life span with and without self-reported musculoskeletal pain. Chronic musculoskeletal pain is a major health related problem in our society. A common complaint related to chronic pain is about cognitive difficulties in attention, memory, and decision making. A number of studies have demonstrated that people with pain also perform wors on tasks measuring, for example episodic memory, semantic memory, and working memory. The present thesis aimed at replying these findings, by using a non-clinical population based sample. the potential differences in memory performance between people with and without pain were examined across the adult life span, in order to disentangle potential pain by age interactions. This was made by using both cross-sectional and longitudinal data. Study I aimed at studying differences in episodic memory performance, semantic memory performance, and implicit memory performance, between people with and without musculoskeletal pain. Differences were found for all three memory systems, but disappeared after controlling for years of formal education. In Study II an extension of the first study was made, in which performance on a range of cognitive tests were analysed. General differences were demonstrated , but yet again, years of education together with depression ruled out the effects. The most robust effects were found for word comprehension and construction ability. Finally, Study III used 5- and 10 year follow up studies to examine change over time in cognitive performance as a function of pain. The main finding from this study was that semantic memory for the oldest is impaired over time as a function of pain. An additional analysis showed similar patterns, regardless of age, for construction ability.
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| 9. |
- Vestergren, Peter, 1974-
(författare)
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On the subjective–objective distinction for measures of memory and cognition : Theoretical and methodological issues in questionnaire development and validation
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aim of this thesis was to develop a questionnaire for cognitive functioning, which could possibly be used as a screening instrument for early signs of dementia in the future. The introduction discusses the often made distinction between subjective and objective measures. A background to the four articles is provided, focussing on findings of weak relationships between self-report- and laboratory measures of memory/cognition. Studies I and II provided results and conclusions that guided instrument development and validation in Studies III and IV. All studies were based on data from participants in the Betula Prospective Cohort Study. Study I investigated predictors of scores on an established self-report instrument for memory failures (PRMQ). Candidate predictors were memory performance on laboratory tests, age, depressive symptoms, and personality traits. There was no relation to age, and test performance did not predict self-reported memory, but depressive symptoms and personality did. Given the finding of a lack of a relation to age, and a bulk of research articles claiming that memory complaints are common in the elderly or increase with age, Study II used a global rating of problems with memory, and reports of perceived causes. In contrast to Study I, problems ratings were related to age, such that increasing age meant higher severity of problems. Furthermore, perceived causes of memory problems differed across age. The elderly reported aging while the young reported stress and multitasking as primary causes. With these results as a background, the purpose of Study III was to develop a new instrument (the Cognitive Dysfunction Questionnaire - CDQ) with the explicit aim that scores should be related to laboratory test performance. A global construct of cognitive functioning with an emphasis on memory systems was adopted, and an item pool was generated. Based on exploratory principal components analysis and correlations with criterion measures (laboratory test performance), twenty items in six domains were selected. Preliminary psychometric evidence showed that the CDQ was reliable, and related to age and objective measures, but not to depressive symptoms. In Study IV, twenty additional items were constructed, and the CDQ was responded to by participants in independent samples. Confirmatory factor analysis was used to test the factor structure derived from Study III, and refinement was undertaken by collapse of two domains and exclusion of items. The final factor structure was cross-validated. Competing models and measurement invariance across age and sex was tested. Psychometric properties were investigated for the final 20-item version.
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| 10. |
- Andersson, Ulf, 1963-
(författare)
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Cognitive deafness : The deterioration of phonological representations in adults with an acquired severe hearing loss and its implications for speech understanding
- 2001
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aim of the present thesis was to examine possible cognitive consequences of acquired hearing loss and the possible impact of these cognitive consequences on the ability to process spoken language presented through visual speechreading or through a cochlear implant.The main findings of the present thesis can be summarised in the following conclusions: (a) The phonological processing capabilities of individuals who have acquired a severe hearing loss or deafness deteriorate progressively as a function of number of years with a complete or partial auditory deprivation. (b) The observed phonological deterioration is restricted to certain aspects of the phonological system. Specifically, the phonological representations of words in the mental lexicon are of less good quality, whereas the phonological system in verbal working memory is preserved. (c) The deterioration of the phonological representations has a negative effect on the individual's ability to process speech, either presented visually (i.e., speechreading) or through a cochlear implant, as it may impair word recognition processes which involve activation of and discrimination between the phonological representations in the lexicon. (d) Thus, the present research describes an acquired cognitive disability not previously documented in the literature, and contributes to the context of other populations with phonological disabilities by showing that a complete or partial deprivation of auditory speech stimulation in adulthood can give rise to a phonological disability. (e) From a clinical point of view, the results from the present thesis suggest that early cochlear implantation after the onset of an acquired severe hearing loss is an important objective in order to reach a high level of speech understanding with the implant.
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| 11. |
- Dahlström, Örjan, et al.
(författare)
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Cognitive training and effects on speech-in noise performance in normal hearing and hearing impaired individuals
- 2015
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Ingår i: CHSCOM2015. - : Linköping University Electronic Press. ; , s. 127-127
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Cognitive training might have potential to improve speech understanding under adverse listening conditions. Here, we have examined the effects of a 5-week computer-based cognitive training program on speech-in-noise-performance, in normal hearing (NH) participants and in participants with mild-to-moderate sensorineural hearing loss (HI).Two groups, matched on gender and age (45-65 years), of 20 participants each (HI and NH respectively) are recruited. Participants perform four test-sessions; inclusion (t0), five weeks (t1), ten weeks (t2) and six months (t3). Training is performed either between t0 and t1, or between t1 and t2 (using a cross-over design), using the computer-based Cogmed training program, approximately 30-40 minutes per day, five days per week, during five weeks. At each session participants are tested in three different ways: (a) cognitive testing (KIPS, SICSPAN, TRT); (b) auditory performance (pure tone-audiometry (air- and bone-conduction) and speech audiometry (HINT, Swedish SPIN-test (SNR +4dB))); (c) cortical activation (MR sessions where participants performed a speech-in-noise task using Hagerman-sentences with steady-state speech-spectrum noise (SSN) and with two competing talkers). MR imaging is performed on a Philips Achieva 1.5 Tesla scanner using a sparse imaging technique in which stimuli are presented during the silent period between successive scans. Participants listen to auditory stimuli under eight different conditions: clear speech, SSN or two competing talkers (each at 90%, 50% and 0% intelligibility), and silent rest. Pre- and post-training, hearing disability is assessed by the Speech-Spatial-Qualities-Questionnaire.The study is on-going and behavioral results as well as results from fMRI will be presented.
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| 12. |
- Levén, Anna, 1976-
(författare)
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Postponed Plans : Prospective Memory and Intellectual Disability
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Avhandlingen handlar om prospektivt minne (PM) hos personer med utvecklingsstörning. PM syftar på att formulera intentioner och genomföra dessa någon gång i framtiden, antingen inom en definierad tidsram eller i samband med en specifik händelse.Frågeställningar:1. Finns det en kvalitativ och kvantitativ skillnad mellan prospektivt minne hos personer med utvecklingsstörning och en kontrollgrupp? (Artikel I – II)2. Hur ser sambandet mellan prospektivt minne, arbetsminne och episodiskt minne ut hos personer med utvecklingsstörning och, skiljer sig detta åt jämfört med kontrollgruppen? (Artikel II)3. Vilka förutsättningar vid inkodning och hågkomst är kompatibla? (Artikel III)4. På vilket sätt kan svag association mellan olika delar av information bidra till prospektiva minnesfel? (Artikel IV)5. Går det att särskilja en hög- respektive lågpresterande grupp personer med utvecklingsstörning med avseende på prospektiv minnesprestation? (Artikel II)Personer med utvecklingsstörning begår fler prospektiva minnesfel än personer i kontrollgruppen. Motsvarande gruppskillnad finns inte för självskattat minne. Prospektiv minnesprestation är bättre med bilder jämfört med ord som prospektiva ledtrådar, mest tydligt för personer med utvecklingsstörning. Arbetsminneskapacitet visade ett samband med både prospektivt minne och antalet falska minnen i kognitivt krävande situationer, till exempel, situationer med flera parallella prospektiva minnesuppgifter. Falska minnen och prospektivt minne hade ett samband hos personer med utvecklingsstörning. Att felaktigt känna igen bilder med bara delvis bekanta delar och att känna igen prospektiva ledtrådar utan att komma ihåg själva intentionen hade ett samband hos personer med utvecklingsstörning. Personer med utvecklingsstörning var också sämre än kontrollgruppen på att upprepa tidsintervall. Detta kan till exempel bero på bristande episodiskt minne och begränsade strategier för att lösa den här typen av uppgifter. Resultaten diskuteras i relation till träning av prospektivt minne och val av hjälpmedel.
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| 13. |
- Rönnberg, Jerker, et al.
(författare)
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On the development of a working memory model for Ease-of Language Understanding (ELU)
- 2013
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Working memory is important for online language processing in a dialogue. We use it to store relevant information, to inhibit or ignore irrelevant information, and to attend to conversation selectively. Working memory helps us keep track of a dialogue while taking turns and following the gist. This paper examines the Ease-of Language Understanding model (i.e., the ELU model, Rönnberg, 2003; Rönnberg et al., 2008) in light of new behavioral and neural findings concerning the role of working memory capacity (WMC) in sound and speech processing. The new ELU model is a meaning prediction system that depends on phonological and semantic interactions in rapid implicit and slower explicit processing mechanisms that both depend on working memory, albeit in different ways. New predictions and clinical implications are outlined.
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| 14. |
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| 15. |
- Sundström, Simon, 1985-
(författare)
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Prosodic and Phonological Ability in Children with Developmental Language Disorder and Children with Hearing Impairment : In the Context of Word and Nonword Repetition
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Many children with developmental language disorder (DLD) exhibit difficulties with phonology, i.e. the sounds of language. Children with any degree of hearing impairment (HI) are at an increased risk of problems with spoken language, including phonology. The cause of these difficulties is unknown in children with DLD, and is often assumed to result from reduced hearing acuity in children with HI. Variability in terms of language outcomes is large in both groups, and determining if a child’s language ability is within normal limits or not is problematic. A task that has proven useful in differentiating typical from atypical language development is nonword repetition, in which the child listens to a word form without meaning and repeats it back immediately. Performance in nonword repetition tasks is a potential indicator of language ability in both children with DLD and children with HI. However, it has not been established exactly what the task measures.In the present thesis, the ability to repeat prosodic and segmental features of real words and nonwords was investigated in Swedish-speaking four- to six-year-old children with DLD and HI, as well as in children with normal hearing and typical language development (TLD) (papers I, II and III). Further, relations of word and nonword repetition ability to language and hearing were explored (papers II and III), along with comparisons of phonological and grammatical production between the groups (paper IV).The findings indicated that the prosodic features stress and tonal word accent affect repetition performance in children with DLD, HI, and TLD. In general, the children with DLD and HI achieved lower results than the children with TLD on repetition of segments (consonants and vowels) and prosodic features, but tonal word accent was repeated with relatively high accuracy. Tonal word accent 1 was more accurately repeated than tonal word accent 2 by the DLD and HI children. The children with TLD repeated tonal word accent with few errors, but segments in nonwords with tonal word accent 2 were easier to repeat than segments in nonwords with tonal word accent 1.The results further revealed that the ability of children with DLD to repeat stress in real words is related to expressive grammar, but repetition of prosodic features does not reflect general language knowledge. In contrast, repetition of both segmental and prosodic nonword features may be indicative of receptive vocabulary, phonological production during naming of familiar words, and expressive grammar in children with HI. Repetition performance might be related to the degree of HI before cochlear implantation or fitting of hearing aids.Children with DLD and children with HI demonstrate similar strengths and weaknesses in phonological and grammatical production, despite the fact that they develop language under different conditions—with and without normal hearing. Tonal word accent use and syntax are relatively unimpaired in DLD and HI children.This thesis highlights prosodic and phonological strengths and weaknesses in children who have, or are at risk of, deficits in language and communication abilities. It also supports word and nonword repetition as potential predictors of some aspects of language ability in children with DLD and HI. Further, it emphasizes the importance of taking prosody into account when constructing, or interpreting results from, repetition tasks. Future research aiming to investigate the relationship between prosody in repetition and language, cognition and hearing, should use longitudinal study designs, and include younger children. Studies comparing prosodic and phonological ability in children with DLD and children with HI should employ both quantitative and qualitative analyses.
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| 16. |
- Wass, Malin
(författare)
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Children with Cochlear Implants : Cognition and Reading Ability
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The present thesis investigated cognitive ability in children with severe to profound hearing impairment who have received cochlear implants (CIs). The auditory stimulation from a cochlear implant early in life influences most cognitive functions as a consequence of the plasticity of the brain in the young child. It is important to understand the cognitive consequences of auditory stimulation from CIs in order to provide adequate support to these children. This thesis examined three specific aspects of cognitive ability (working memory, phonological skill and lexical access), and reading ability in children with CIs, as compared to children with normal hearing in the same age. The relations between cognitive abilities and reading skills were also investigated, as well as the associations between demographic variables (e.g., age at implantation and communication mode), cognitive abilities and reading skills. The children with CI generally had lower performance levels than the normal hearing children in tasks of phonological and general working memory, phonological skills and lexical access. They had specific problems in tasks with high demands on phonological working memory, whereas their performance levels in tasks of visuospatial working memory were on par with the hearing children. A majority of the children with CI demonstrated reading skills within the normal range for hearing children, both for decoding and reading comprehension. The relations between demographic factors and cognitive skills varied somewhat between the studies. The patterns of result are discussed with reference to contemporary theories of working memory, phonological skills, and lexical access.
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| 17. |
- Wåhlstedt, Cecilia, 1960-
(författare)
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Specifying the Heterogeneity in Children with ADHD : Symptom Domains, Neuropsychological Processes, and Comorbidity
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Heterogeneity in children with Attention Deficit Hyperactivity Disorder (ADHD) symptoms is a well-known phenomenon. Empirically, this heterogeneity is evident in at least three different respects: expression of the two ADHD symptom domains (hyperactivity/impulsivity and inattention), neuropsychological impairments, and comorbid behavior problems. The major aim of the present thesis was to examine the heterogeneity characterizing children with ADHD symptoms to enhance our understanding by examining neuropsychological factors with regard to common and independent contributions, and specificity of the two ADHD symptom domains in relation to neuropsychological factors and comorbid behavioral problems. Particular emphasis is placed on prominent neuropsychological processes such as executive functions, state regulation and delay aversion. The present thesis is based on findings from four studies on community-based samples of children – studies involving concurrent and longitudinal designs as well as both categorical and dimensional approaches.Results provide support for the notion that executive function and state regulation, but not delay aversion, constitute independent pathways to ADHD, primarily to symptoms of inattention. However, delay aversion was shown to have an effect in combination with state regulation on both hyperactivity/impulsivity and inattention. Additionally, symptoms of hyperactivity/impulsivity and inattention have different primary correlates concerning neuropsychological factors and comorbidity. More specifically, executive function, state regulation, internalizing problems and academic achievement were specifically related to inattention but not to hyperactivity/impulsivity. Oppositional Defiant Disorder (ODD) was specifically related to hyperactivity/impulsivity, but not to inattention.The present thesis has contributed with important and new knowledge about the heterogeneity of children with ADHD symptoms concerning neuropsychological pathways, and specificity of the two ADHD symptom domains in relation to neuropsychological factors and comorbid behavioral problems. Knowledge such as this can help us understand how to identify more homogeneous ADHD subgroups, and contribute to the further development of multiple pathway models within this area of research.
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