| 1. |
- Mishra, Sushmit, 1981-
(författare)
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Exploring Cognitive Spare Capacity : Executive Processing of Degraded Speech
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Cognitive resources, specifically working memory capacity are used for listening to speech, especially in noise. Cognitive resources are limited, and if listeners allocate a greater share of these resources to recovering the input signal in noise, fewer resources are available for interpreting and encoding its linguistic content. Although the importance of CSC for individual success in communicative situations has been acknowledged, this concept has not hitherto been explored experimentally. In this thesis, a CSC test (CSCT) was developed and administered to young adults with normal hearing and older adults with age-related hearing loss. CSCT required executive processing of speech at different memory loads with and without visual cues in different noise conditions. A free recall task using the same material was administered for comparison purposes and a battery of cognitive tests was administered to understand the relation between CSC and established cognitive concepts. The aims of the thesis were to investigate how CSC is influenced by 1) different executive demands and memory loads; 2) background noise; 3) visual cues; 4) aging and concomitant hearing loss. The results showed that 1) CSC was sensitive to memory load, and updating demands reduced CSC more than inhibition demands; 2) CSC was reduced in background noise compared to quiet; 3) visual cues enhanced CSC especially in noise; 4) CSC was reduced with ageing and concomitant hearing loss especially when visual cues were absent, memory demands were increased and background noise was speech-like. The main finding of this thesis was that visual cues enhanced CSC for older individuals with hearing loss, specifically in adverse listening conditions. This demonstrates the importance of audiovisual testing in audiological assessment. Further, specific cognitive resources depleted during listening in noise were at least partially compensated by other cognitive functions. This thesis is the first step towards a theoretical understanding of CSC and in future, tests of CSC may play a crucial role in planning rehabilitation of persons with hearing loss.
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| 2. |
- Classon, Elisabet, 1965-
(författare)
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Representing sounds and spellings : Phonological decline and compensatory working memory in acquired hearing impairment
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis examined phonological processing in adults with postlingually acquired moderate-to-severe hearing impairment (HI) and whether explicit working memory processing of phonology and individual working memory capacity (WMC) can compensate for degraded phonological representations in this group (papers I-III). A second aim was to provide reference data for a test of WMC, the reading span test, and to examine the relation between reading span test performance and speech recognition in noise in a larger sample of 50-89 year olds with HI (paper IV). Non-auditory tasks of phonological processing, episodic long-term memory and WMC were used in papers I-III, and both behavioral and electrophysiological measures were collected. Results showed that phonological processing was impaired in the group with HI but that WMC and explicit working memory processing of phonology could be employed to compensate for degraded phonological representations. However, this compensation may come at the cost of interfering with episodic memory encoding. An electrophysiological marker of HI in text-based rhyme judgments was found. Paper IV presented reference data for reading span test performance in two versions of the test in individuals with HI, and results suggesting that WMC may be differentially predictive of speech recognition in noise in different age groups of older adults with HI. The clinical implications of the present results concerns the double disadvantage of individuals with lower WMC and HI. A structured assessment of WMC in rehabilitative settings would help to identify these individuals and tailor treatment to their needs. The reading span test is suggested as a suitable future candidate for clinical WMC assessment.
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| 3. |
- Ng, Hoi Ning Elaine
(författare)
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Cognition in Hearing Aid Users : Memory for Everyday Speech
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The thesis investigated the importance of cognition for speech understanding in experienced and new hearing aid users. The aims were 1) to develop a cognitive test (Sentence-final Word Identification and Recall, or SWIR test) to measure the effects of a noise reduction algorithm on processing of highly intelligible speech (everyday sentences); 2) to investigate, using the SWIR test, whether hearing aid signal processing would affect memory for heard speech in experienced hearing aid users; 3) to test whether the effects of signal processing on the ability to recall speech would interact with background noise and individual differences in working memory capacity; 4) to explore the potential clinical application of the SWIR test; and 5) to examine the relationship between cognition and speech recognition in noise in new users over the first six months of hearing aid use. Results showed that, for experienced users, noise reduction freed up cognitive resources and alleviated the negative impact of noise on memory when speech stimuli were presented in a background of speech babble spoken in the listener’s native language. The possible underlying mechanisms are that noise reduction facilitates auditory stream segregation between target and irrelevant speech and reduces the attention captured by the linguistic information in irrelevant speech. The effects of noise reduction and SWIR performance were modulated by individual differences in working memory capacity. SWIR performance was related to the self-reported outcome of hearing aid use. For new users, working memory capacity played a more important role in speech recognition in noise before acclimatization to hearing aid amplification than after six months. This thesis demonstrates for the first time that hearing aid signal processing can significantly improve the ability of individuals with hearing impairment to recall highly intelligible speech stimuli presented in babble noise. It also adds to the literature showing the key role of working memory capacity in listening with hearing aids, especially for new users. By virtue of its relation to subjective measures of hearing aid outcome, the SWIR test can potentially be used as a tool in assessing hearing aid outcome.
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| 4. |
- Andin, Josefine
(författare)
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Dealing with Digits : Arithmetic, Memory and Phonology in Deaf Signers
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Deafness has been associated with poor abilities to deal with digits in the context of arithmetic and memory, and language modality-specific differences in the phonological similarity of digits have been shown to influence short-term memory (STM). Therefore, the overall aim of the present thesis was to find out whether language modality-specific differences in phonological processing between sign and speech can explain why deaf signers perform at lower levels than hearing peers when dealing with digits. To explore this aim, the role of phonological processing in digit-based arithmetic and memory tasks was investigated, using both behavioural and neuroimaging methods, in adult deaf signers and hearing non-signers, carefully matched on age, sex, education and non-verbal intelligence. To make task demands as equal as possible for both groups, and to control for material effects, arithmetic, phonological processing, STM and working memory (WM) were all assessed using the same presentation and response mode for both groups. The results suggested that in digit-based STM, phonological similarity of manual numerals causes deaf signers to perform more poorly than hearing non-signers. However, for digit-based WM there was no difference between the groups, possibly due to differences in allocation of resources during WM. This indicates that similar WM for the two groups can be generalized from lexical items to digits. Further, we found that in the present work deaf signers performed better than expected and on a par with hearing peers on all arithmetic tasks, except for multiplication, possibly because the groups studied here were very carefully matched. However, the neural networks recruited for arithmetic and phonology differed between groups. During multiplication tasks, deaf signers showed an increased reliance on cortex of the right parietal lobe complemented by the left inferior frontal gyrus. In contrast, hearing non-signers relied on cortex of the left frontal and parietal lobes during multiplication. This suggests that while hearing non-signers recruit phonology-dependent arithmetic fact retrieval processes for multiplication, deaf signers recruit non-verbal magnitude manipulation processes. For phonology, the hearing non-signers engaged left lateralized frontal and parietal areas within the classical perisylvian language network. In deaf signers, however, phonological processing was limited to cortex of the left occipital lobe, suggesting that sign-based phonological processing does not necessarily activate the classical language network. In conclusion, the findings of the present thesis suggest that language modality-specific differences between sign and speech in different ways can explain why deaf signers perform at lower levels than hearing non-signers on tasks that include dealing with digits.
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| 5. |
- Blomberg, Rina, 1974-
(författare)
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Auditory Distraction in ADHD : From Behaviour to the Brain
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- ADHD is a heterogenous disorder encompassing neurodevelopmental deficits in cognitive control. Auditory distraction is a common clinically reported symptom in ADHD, yet empirical research investigating the manifestation of auditory distraction in the disorder is remarkably scarce. Findings from cognitive hearing science highlight the crucial role cognitive control plays in an individual’s ability to gate, attenuate and/or compensate for auditory distraction. However the field is yet to extensively test hypotheses in normal hearing populations with neurodevelopmental deficits in cognitive control such as ADHD. This thesis contributes to narrowing the gap within these two fields of research by studying auditory distraction in this clinical population to a greater extent than previous reports in the literature.Using a combination of both behavioural and neuroimaging methods, the research presented here was able to show that adults and adolescents with ADHD are inherently more susceptible to auditory distraction than their non-ADHD counterparts. At the behavioural level, impaired task performance due to auditory distraction was more likely to manifest in ADHD participants when the working memory system was under high processing load. At the neural level, functional aberrancy in auditory attention was evident at early stages of sensory processing in a variety of tasks, implicating both exogenous and endogenous control systems in ADHD. Furthermore, the distribution of ADHD-symptom severity across participants was shown to correlate with increases in both cortical activity to auditory distractors and intrinsic functional connectivity between auditory and exogenous attention networks.In line with evidence from cognitive hearing science, the general findings of this thesis demonstrate that cognitive control plays an important role in the ability to perceive sound under suboptimal listening conditions and hamper distraction. In addition, findings challenge theories of ADHD that question the extent in which sensory-related attentional control is impaired. More empirical research on the auditory modality in ADHD is therefore encouraged in order to revise models, improve diagnostic tools, and develop evidence-based interventions targeting study/work environments.
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| 6. |
- Palmqvist, Lisa, 1987-
(författare)
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Time to Plan : How to support everyday planning in adolescents with intellectual disability
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Children and adolescents with intellectual disability (ID) have difficulties in executive functioning and when coping with everyday planning tasks. However, the literature cannot explain whether individuals with ID perform according to their developmental level or not. The studies in this thesis investigated if life experience could be a contributing factor to the diversity seen in the literature. Planning performance can be improved by either using external or internal support. Assistive technology for cognition (ATC) is an example of external support. This thesis investigated how the ATC is being used in an everyday planning situation which has not been investigated before. Furthermore, this thesis explored whether the internal supports of cognitive abilities and life experience correlate with planning ability in adolescents with ID, and if planning ability can be trained using a cognitive training program for everyday planning. Results showed that ATC supported cognitive functions, but that the children did not formulate the plans themselves. Furthermore, the results support the difference model of ID since planning correlated with different cognitive measures and life experience in adolescents with ID compared to children with a typical development. Adolescents with ID got better at the planning tasks in the training program, however, no transfer effects to untrained planning tasks were found. To conclude, the planning was supported by external and internal support. However, ATC needs to be designed and prescribed in a way that increases independence. Practitioners should actively support in training planning and should be cautious when introducing cognitive interventions if the transfer gap is too large.
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| 7. |
- Micula, Andreea, 1991-
(författare)
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Cognition Seen Through the Eyes of Hearing Aid Users : Working Memory Resource Allocation for Speech Perception and Recall
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis investigates how hearing aid users allocate working (WM) memory resources under various task demands when listening to and storing speech in memory for later recall. This was done by combining an auditory recall task, the Sentence-final Word Identification and Recall (SWIR) test, with pupillometry. Different pupillary responses were used to obtain insights into momentary WM resource allocation and overall WM resource allocation over time. The task demands were manipulated by varying hearing aid noise reduction settings, as well as by varying the task difficulty of the SWIR test and the task difficulty predictability.The findings from the first two studies showed that recall performance in competing speech was better, and baseline pupillary responses were higher when noise reduction was activated compared to when it was not. This indicates that attenuating background noise frees up WM resources to be used for storing speech in memory rather than speech processing. While unpredictable task difficulty elicited higher baseline pupillary responses than predictable task difficulty, it did not have any effect on recall performance. This finding suggests that task difficulty predictability does not affect WM resource allocation. Instead, unpredictable task difficulty may lead to increased alertness in anticipation of the end of the SWIR test list. The findings of the third study showed that increased transient task-evoked pupillary responses, which reflect the momentary intensity of attention during encoding, were associated with a higher likelihood of subsequent recall. Moreover, higher WM capacity was also linked to higher likelihood of subsequent recall, presumably due to the ability to allocate more attentional resources during encoding. Lastly, the findings from the fourth study indicated that the combination of the SWIR test and pupillometry is suitable for capturing WM resource allocation. Although arousal decreased over time, recall performance remained stable, suggesting that participants did not reach the point of disengagement.Overall, a novel learning from this thesis is that increased pupillary responses may be a marker of “successful effort” when additional WM resources are allocated to achieve a better recall performance in the SWIR test. Furthermore, this thesis gives insights into which factors affect WM resource allocation and how to reduce the amount of processing resources required to understand speech, which may contribute to optimizing auditory rehabilitation in the future.
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| 8. |
- Moradi, Shahram
(författare)
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Time is of the essence in speech perception! : Get it fast, or think about it
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The present thesis examined the extent to which background noise influences the isolation point (IP, the shortest time from the onset of speech stimulus required for correct identification of that speech stimulus) and accuracy in identification of different types of speech stimuli (consonants, words, and final words in high-predictable [HP] and low-predictable [LP] sentences). These speech stimuli were presented in different modalities of presentation (auditory, visual, and audiovisual) to young normal-hearing listeners (Papers 1, 2, and 5). In addition, the present thesis studied under what conditions cognitive resources were explicitly demanded in identification of different types of speech stimuli (Papers 1 and 2). Further, elderly hearing-aid (EHA) users and elderly normal-hearing (ENH) listeners were compared with regard to the IPs, accuracy, and under what conditions explicit cognitive resources were demanded in identification of auditory speech stimuli in silence (Paper 3). The results showed that background noise resulted in later IPs and reduced the accuracy for the identification of different types of speech stimuli in both modalities of speech presentation. Explicit cognitive resources were demanded in identification of speech stimuli in the auditory-only modality, under the noisy condition, and in the absence of a prior semantic context. In addition, audiovisual presentation of speech stimuli resulted in earlier IPs and more accurate identification of speech stimuli than auditory presentation. Furthermore, a pre-exposure to audiovisual speech stimuli resulted in better auditory speech-in-noise identification than an exposure to auditory-only speech stimuli (Papers 2 and 4). When comparing EHA users and ENH individuals, the EHA users showed inferior performance in the identification of consonants, words, and final words in LP sentences (in terms of IP). In terms of accuracy, the EHA users demonstrated inferior performance only in the identification of consonants and words. Only the identification of consonants and words demanded explicit cognitive resources in the EHA users. Theoretical predictions and clinical implications were discussed.
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| 9. |
- Sundqvist, Annette (Anett), 1968-
(författare)
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Knowing me, knowing you : Mentalization abilities of children who use augmentative and alternative communication
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The present thesis investigated several components important to the understanding of mentalization for children who use augmentative and alternative communication (AAC). The result of the thesis demonstrated that non-verbal mental age correlated significantly with mentalization tasks, and that the participants did not significantly differ compared to a nonverbal age-matched group of children without disabilities. Different expression of active participation, which is necessary to be able to display mentalization in dialogue, was observed in analysed interaction. The children’s social networks were limited and consisted of very few peers, thus limiting the possibilities of active participation. The number of peers in the children’s social networks correlated significantly with aspects of the children’s mentalization ability. Children who use AAC display their mentalization abilities independently in social interaction and through e-mail messages to peers. A wider construct that will have relevance to mentalization in ordinary situations is described encompassing several different abilities. The development of these abilities is dependent on the child’s capacity for adapting a cognitive flexibility when reflecting and theorizing on what is happening in a given situation. The development of mentalization is also dependent on a child’s close friendships, active participation in interaction, functional language ability, and varied social networks consisting of both peers and adults.
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| 10. |
- Sörqvist, Patrik
(författare)
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The role of working memory capacity in auditory distraction
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The basis of individual differences in susceptibility to auditory distraction has been a research field largely ignored. The current work presents four studies demonstrating that individual differences in working memory capacity (WMC) are related to the magnitude of auditory distraction. The first three reports showed that high WMC attenuates the effects of speech and aircraft noise on reading comprehension and prose memory. The fourth report showed that high WMC attenuates the power of unexpected sound stimulation to capture our attention, but not the interference from changing-state sound streams to seriation processes.Furthermore, the first and the second report showed that the capacity to exclude new, potentially relevant but ultimately irrelevant, materials from memory underlies the relationship between WMC and the effects of speech on reading comprehension/prose memory. Based on these results, a new perspective of WMC called the "sub-process view" was developed, according to which WMC is a compound of functionally distinct subprocesses: some of which are related to auditory distraction. Ten years ago it was not at all clear if cognitive-control processes play a role in auditory distraction, but the studies reported in this thesis strongly suggest that cognitive-control - as reflected in WMC -constitutes a fundamental basis of individual differences in susceptibility to auditory distraction.
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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. |
- Ferreira, Janna, 1973-
(författare)
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Sounds of silence : Phonological awareness and written language in children with and without speech
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Avhandlingens övergripande syfte var att undersöka fonologisk medvetenhet och skriftspråklig förmåga hos talande eller icke-talande barn, med lässvårigheter eller motoriska talsvårigheter. De huvudsakliga fynden i denna avhandling var: (1) För barn med lässvårigheter som befinner sig på en tidig nivå i sin läsutveckling bör intervention kring läs- och skrivförmågor fokusera på barnets svaghet snarare än styrkan vad gäller ordavkodning. (2) För barn med lässvårigheter hade såväl fonologisk som ortografisk intervention effekt på förmågan att läsa och skriva. Fonologisk intervention hade effekt även på barnen med lägst läsförmåga. (3) För barn med motoriska talsvårigheter var det signifikanta skillnader mellan de bästa och de sämsta läsarna vad gäller auditiv fonemdiskrimination och generella språkförmågor. (4) För barn med motoriska talsvårigheter hade fonologisk intervention effekt på förmågan att stava ord men inte på läsförmågan. (5) I en analys av nonsensord undersöktes stavfel hos en flicka med anartri. Fler stavfel återfanns i längre ord och en högre grad av fel återfanns i mitten av ord, vilket tyder på svårigheter med arbetsminne och med att segmentera ord.Fynden diskuteras i relation till fonologisk informationsbearbetning inom fyra delområden: fonologiska representationer, fonologisk produktion, fonologiskt minne och fonologisk medvetenhet. Talets betydelse för läs- och skrivförmågan är komplex. Även ett gravt avvikande tal kan ge fonologisk återkoppling och för barn med anartri tycks bristen på tal spela en viss roll.Denna avhandling har ett handikappvetenskapligt synsätt och bidrar till den övergripande förståelsen av fonologisk medvetenhet och skriftspråklig förmåga. Flera av fynden är direkt applicerbara i kliniska sammanhang.
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| 13. |
- Homman, Lina, et al.
(författare)
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A structural equation mediation model captures the predictions amongst the parameters of the ease of language understanding model
- 2023
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Ingår i: Frontiers in Psychology. - : Frontiers Media S.A.. - 1664-1078. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The aim of the present study was to assess the validity of the Ease of Language Understanding (ELU) model through a statistical assessment of the relationships among its main parameters: processing speed, phonology, working memory (WM), and dB Speech Noise Ratio (SNR) for a given Speech Recognition Threshold (SRT) in a sample of hearing aid users from the n200 database.Methods: Hearing aid users were assessed on several hearing and cognitive tests. Latent Structural Equation Models (SEMs) were applied to investigate the relationship between the main parameters of the ELU model while controlling for age and PTA. Several competing models were assessed.Results: Analyses indicated that a mediating SEM was the best fit for the data. The results showed that (i) phonology independently predicted speech recognition threshold in both easy and adverse listening conditions and (ii) WM was not predictive of dB SNR for a given SRT in the easier listening conditions (iii) processing speed was predictive of dB SNR for a given SRT mediated via WM in the more adverse conditions.Conclusion: The results were in line with the predictions of the ELU model: (i) phonology contributed to dB SNR for a given SRT in all listening conditions, (ii) WM is only invoked when listening conditions are adverse, (iii) better WM capacity aids the understanding of what has been said in adverse listening conditions, and finally (iv) the results highlight the importance and optimization of processing speed in conditions when listening conditions are adverse and WM is activated.
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| 14. |
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| 15. |
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| 16. |
- 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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