| 1. |
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| 2. |
- Hollestelle, Antoinette, et al.
(author)
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No clinical utility of KRAS variant rs61764370 for ovarian or breast cancer
- 2016
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In: Gynecologic Oncology. - : Elsevier BV. - 0090-8258 .- 1095-6859. ; 141:2, s. 386-401
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Journal article (peer-reviewed)abstract
- Objective Clinical genetic testing is commercially available for rs61764370, an inherited variant residing in a KRAS 3′ UTR microRNA binding site, based on suggested associations with increased ovarian and breast cancer risk as well as with survival time. However, prior studies, emphasizing particular subgroups, were relatively small. Therefore, we comprehensively evaluated ovarian and breast cancer risks as well as clinical outcome associated with rs61764370. Methods Centralized genotyping and analysis were performed for 140,012 women enrolled in the Ovarian Cancer Association Consortium (15,357 ovarian cancer patients; 30,816 controls), the Breast Cancer Association Consortium (33,530 breast cancer patients; 37,640 controls), and the Consortium of Modifiers of BRCA1 and BRCA2 (14,765 BRCA1 and 7904 BRCA2 mutation carriers). Results We found no association with risk of ovarian cancer (OR = 0.99, 95% CI 0.94-1.04, p = 0.74) or breast cancer (OR = 0.98, 95% CI 0.94-1.01, p = 0.19) and results were consistent among mutation carriers (BRCA1, ovarian cancer HR = 1.09, 95% CI 0.97-1.23, p = 0.14, breast cancer HR = 1.04, 95% CI 0.97-1.12, p = 0.27; BRCA2, ovarian cancer HR = 0.89, 95% CI 0.71-1.13, p = 0.34, breast cancer HR = 1.06, 95% CI 0.94-1.19, p = 0.35). Null results were also obtained for associations with overall survival following ovarian cancer (HR = 0.94, 95% CI 0.83-1.07, p = 0.38), breast cancer (HR = 0.96, 95% CI 0.87-1.06, p = 0.38), and all other previously-reported associations. Conclusions rs61764370 is not associated with risk of ovarian or breast cancer nor with clinical outcome for patients with these cancers. Therefore, genotyping this variant has no clinical utility related to the prediction or management of these cancers.
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| 3. |
- Klionsky, Daniel J., et al.
(author)
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Guidelines for the use and interpretation of assays for monitoring autophagy
- 2012
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In: Autophagy. - : Informa UK Limited. - 1554-8635 .- 1554-8627. ; 8:4, s. 445-544
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Research review (peer-reviewed)abstract
- In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.
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| 4. |
- Lawrenson, Kate, et al.
(author)
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Functional mechanisms underlying pleiotropic risk alleles at the 19p13.1 breast-ovarian cancer susceptibility locus
- 2016
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In: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 7
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Journal article (peer-reviewed)abstract
- A locus at 19p13 is associated with breast cancer (BC) and ovarian cancer (OC) risk. Here we analyse 438 SNPs in this region in 46,451 BC and 15,438 OC cases, 15,252 BRCA1 mutation carriers and 73,444 controls and identify 13 candidate causal SNPs associated with serous OC (P=9.2 × 10-20), ER-negative BC (P=1.1 × 10-13), BRCA1-associated BC (P=7.7 × 10-16) and triple negative BC (P-diff=2 × 10-5). Genotype-gene expression associations are identified for candidate target genes ANKLE1 (P=2 × 10-3) and ABHD8 (P<2 × 10-3). Chromosome conformation capture identifies interactions between four candidate SNPs and ABHD8, and luciferase assays indicate six risk alleles increased transactivation of the ADHD8 promoter. Targeted deletion of a region containing risk SNP rs56069439 in a putative enhancer induces ANKLE1 downregulation; and mRNA stability assays indicate functional effects for an ANKLE1 3′-UTR SNP. Altogether, these data suggest that multiple SNPs at 19p13 regulate ABHD8 and perhaps ANKLE1 expression, and indicate common mechanisms underlying breast and ovarian cancer risk.
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| 5. |
- Jansen, Willemijn J, et al.
(author)
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Association of Cerebral Amyloid-β Aggregation With Cognitive Functioning in Persons Without Dementia.
- 2018
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In: JAMA psychiatry. - : American Medical Association (AMA). - 2168-6238 .- 2168-622X. ; 75:1, s. 84-95
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Journal article (peer-reviewed)abstract
- Cerebral amyloid-β aggregation is an early event in Alzheimer disease (AD). Understanding the association between amyloid aggregation and cognitive manifestation in persons without dementia is important for a better understanding of the course of AD and for the design of prevention trials.To investigate whether amyloid-β aggregation is associated with cognitive functioning in persons without dementia.This cross-sectional study included 2908 participants with normal cognition and 4133 with mild cognitive impairment (MCI) from 53 studies in the multicenter Amyloid Biomarker Study. Normal cognition was defined as having no cognitive concerns for which medical help was sought and scores within the normal range on cognitive tests. Mild cognitive impairment was diagnosed according to published criteria. Study inclusion began in 2013 and is ongoing. Data analysis was performed in January 2017.Global cognitive performance as assessed by the Mini-Mental State Examination (MMSE) and episodic memory performance as assessed by a verbal word learning test. Amyloid aggregation was measured with positron emission tomography or cerebrospinal fluid biomarkers and dichotomized as negative (normal) or positive (abnormal) according to study-specific cutoffs. Generalized estimating equations were used to examine the association between amyloid aggregation and low cognitive scores (MMSE score ≤27 or memory z score≤-1.28) and to assess whether this association was moderated by age, sex, educational level, or apolipoprotein E genotype.Among 2908 persons with normal cognition (mean [SD] age, 67.4 [12.8] years), amyloid positivity was associated with low memory scores after age 70 years (mean difference in amyloid positive vs negative, 4% [95% CI, 0%-7%] at 72 years and 21% [95% CI, 10%-33%] at 90 years) but was not associated with low MMSE scores (mean difference, 3% [95% CI, -1% to 6%], P=.16). Among 4133 patients with MCI (mean [SD] age, 70.2 [8.5] years), amyloid positivity was associated with low memory (mean difference, 16% [95% CI, 12%-20%], P<.001) and low MMSE (mean difference, 14% [95% CI, 12%-17%], P<.001) scores, and this association decreased with age. Low cognitive scores had limited utility for screening of amyloid positivity in persons with normal cognition and those with MCI. In persons with normal cognition, the age-related increase in low memory score paralleled the age-related increase in amyloid positivity with an intervening period of 10 to 15 years.Although low memory scores are an early marker of amyloid positivity, their value as a screening measure for early AD among persons without dementia is limited.
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| 6. |
- Jansen, Willemijn J, et al.
(author)
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Prevalence of cerebral amyloid pathology in persons without dementia: a meta-analysis.
- 2015
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In: JAMA. - : American Medical Association (AMA). - 1538-3598 .- 0098-7484. ; 313:19, s. 1924-38
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Journal article (peer-reviewed)abstract
- Cerebral amyloid-β aggregation is an early pathological event in Alzheimer disease (AD), starting decades before dementia onset. Estimates of the prevalence of amyloid pathology in persons without dementia are needed to understand the development of AD and to design prevention studies.
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| 7. |
- Mattsson, Niklas, et al.
(author)
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Prevalence of the apolipoprotein E epsilon 4 allele in amyloid beta positive subjects across the spectrum of Alzheimers disease
- 2018
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In: Alzheimer's & Dementia. - : ELSEVIER SCIENCE INC. - 1552-5260 .- 1552-5279. ; 14:7, s. 913-924
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Journal article (peer-reviewed)abstract
- Introduction: Apolipoprotein E (APOE) epsilon 4 is the major genetic risk factor for Alzheimers disease (AD), but its prevalence is unclear because earlier studies did not require biomarker evidence of amyloid beta(A beta) pathology. Methods: We included 3451 A beta+ subjects (853 AD-type dementia, 1810 mild cognitive impairment, and 788 cognitively normal). Generalized estimating equation models were used to assess APOE epsilon 4 prevalence in relation to age, sex, education, and geographical location. Results: The APOE epsilon 4 prevalence was 66% in AD-type dementia, 64% in mild cognitive impairment, and 51% in cognitively normal, and it decreased with advancing age in A beta+ cognitively normal and A beta+ mild cognitive impairment (P amp;lt;.05) but not in A beta+ AD dementia (P =.66). The prevalence was highest in Northern Europe but did not vary by sex or education. Discussion: The APOE E4 prevalence in AD was higher than that in previous studies, which did not require presence of A beta pathology. Furthermore, our results highlight disease heterogeneity related to age and geographical location. (C) 2018 the Alzheimers Association. Published by Elsevier Inc. All rights reserved.
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| 8. |
- Mattsson, Niklas, et al.
(author)
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Prevalence of the apolipoprotein E ε4 allele in amyloid β positive subjects across the spectrum of Alzheimer's disease
- 2018
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In: Alzheimer's and Dementia. - : Wiley. - 1552-5260 .- 1552-5279. ; 14:7, s. 913-924
-
Journal article (peer-reviewed)abstract
- Introduction: Apolipoprotein E (APOE) ε4 is the major genetic risk factor for Alzheimer's disease (AD), but its prevalence is unclear because earlier studies did not require biomarker evidence of amyloid β (Aβ) pathology. Methods: We included 3451 Aβ+ subjects (853 AD-type dementia, 1810 mild cognitive impairment, and 788 cognitively normal). Generalized estimating equation models were used to assess APOE ε4 prevalence in relation to age, sex, education, and geographical location. Results: The APOE ε4 prevalence was 66% in AD-type dementia, 64% in mild cognitive impairment, and 51% in cognitively normal, and it decreased with advancing age in Aβ+ cognitively normal and Aβ+ mild cognitive impairment (P <.05) but not in Aβ+ AD dementia (P =.66). The prevalence was highest in Northern Europe but did not vary by sex or education. Discussion: The APOE ε4 prevalence in AD was higher than that in previous studies, which did not require presence of Aβ pathology. Furthermore, our results highlight disease heterogeneity related to age and geographical location.
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| 9. |
- Aczel, Balazs, et al.
(author)
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Consensus-based guidance for conducting and reporting multi-analyst studies
- 2021
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In: eLIFE. - : eLife Sciences Publications. - 2050-084X. ; 10
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Journal article (peer-reviewed)abstract
- Any large dataset can be analyzed in a number of ways, and it is possible that the use of different analysis strategies will lead to different results and conclusions. One way to assess whether the results obtained depend on the analysis strategy chosen is to employ multiple analysts and leave each of them free to follow their own approach. Here, we present consensus-based guidance for conducting and reporting such multi-analyst studies, and we discuss how broader adoption of the multi-analyst approach has the potential to strengthen the robustness of results and conclusions obtained from analyses of datasets in basic and applied research.
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| 10. |
- Barrett, Jennifer H., et al.
(author)
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Fine mapping of genetic susceptibility loci for melanoma reveals a mixture of single variant and multiple variant regions
- 2015
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In: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 136:6, s. 1351-1360
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Journal article (peer-reviewed)abstract
- At least 17 genomic regions are established as harboring melanoma susceptibility variants, in most instances with genome-wide levels of significance and replication in independent samples. Based on genome-wide single nucleotide polymorphism (SNP) data augmented by imputation to the 1,000 Genomes reference panel, we have fine mapped these regions in over 5,000 individuals with melanoma (mainly from the GenoMEL consortium) and over 7,000 ethnically matched controls. A penalized regression approach was used to discover those SNP markers that most parsimoniously explain the observed association in each genomic region. For the majority of the regions, the signal is best explained by a single SNP, which sometimes, as in the tyrosinase region, is a known functional variant. However in five regions the explanation is more complex. At the CDKN2A locus, for example, there is strong evidence that not only multiple SNPs but also multiple genes are involved. Our results illustrate the variability in the biology underlying genome-wide susceptibility loci and make steps toward accounting for some of the missing heritability. What's new? In genome-wide association studies, researchers identify genetic variants that frequently associate with a particular disease, though the variants identified may not contribute to the molecular cause of the disease. This study took a closer look at 17 regions associated with melanoma, fine mapping the regions both in people with melanoma and in healthy controls. Though single SNPs account for the association in some regions, they found that in a few regions, several SNPs - and possibly multiple genes - contributed to the association signal. These findings illustrate the importance of not overlooking the interaction between multiple genetic markers when conducting such studies.
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| 11. |
- Nygren, M., et al.
(author)
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Gender Differences in Children's Voice Use in a Day Care Environment
- 2012
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In: Journal of Voice. - : Elsevier BV. - 0892-1997 .- 1873-4588. ; 26:6
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Journal article (peer-reviewed)abstract
- Background. The prevalence of dysphonia is higher in boys than in girls before puberty. This could be because of the differences in boys' and girls' voice use. Previous research on gender differences in prepubescent children's voice parameters has been contradictory. Most studies have focused on examining fundamental frequency. Objectives. The purpose of this study was to investigate voice use in boys and girls in a day care environment based on the voice parameters fundamental frequency (Hz), vocal intensity (dB SPL), and phonation time (%) and to ascertain whether there were any significant gender differences. Study Design. Prospective comparative design. Method. The study was conducted in a day care environment where 30 children (17 boys and 13 girls aged 4-5 years) participated. The participants' voices were measured continuously for 4 hours with a voice accumulator that registered fundamental frequency, vocal intensity level, phonation time, and background noise. Results. Mean (standard deviation) fundamental frequency was 310 (22) and 321 (16) Hz, vocal intensity was 93 (4) and 91 (3) dB SPL, and phonation time was 7.7 (2.0)% and 7.6 (2.5)% for boys and girls, respectively. No differences between genders were statistically significant. Conclusion. The finding of no statistically significant gender differences for measurements of voice parameters in a group of children aged 4-5 years in a day care environment is an important finding that contributes to increased knowledge about young boys' and girls' voice use.
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| 12. |
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| 13. |
- Hessels, Roy S, et al.
(author)
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Eye contact avoidance in crowds : A large wearable eye-tracking study
- 2022
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In: Attention, Perception & Psychophysics. - : Springer Science and Business Media LLC. - 1943-3921 .- 1943-393X. ; 84:8, s. 2623-2640
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Journal article (peer-reviewed)abstract
- Eye contact is essential for human interactions. We investigated whether humans are able to avoid eye contact while navigating crowds. At a science festival, we fitted 62 participants with a wearable eye tracker and instructed them to walk a route. Half of the participants were further instructed to avoid eye contact. We report that humans can flexibly allocate their gaze while navigating crowds and avoid eye contact primarily by orienting their head and eyes towards the floor. We discuss implications for crowd navigation and gaze behavior. In addition, we address a number of issues encountered in such field studies with regard to data quality, control of the environment, and participant adherence to instructions. We stress that methodological innovation and scientific progress are strongly interrelated.
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| 14. |
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| 15. |
- Karlsson, Fredrik, 1975-, et al.
(author)
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Articulatory closure proficiency in Parkinson's disease patients following deep brain stimulation of the subthalamic nucleus and caudal zona incerta.
- 2014
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In: Journal of Speech, Language and Hearing Research. - 1092-4388 .- 1558-9102. ; 57, s. 1178-1190
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Journal article (peer-reviewed)abstract
- OBJECTIVEThe present study aimed at comparing the effects of deep brain stimulation (DBS) treatment of the subthalamic nucleus (STN) and the caudal zona incerta (cZi) on Parkinson's disease patients' proficiency in achieving oral closure and release during plosive production. METHODS Nineteen patients were evaluated preoperatively and 12 months after DBS surgery. Nine patients were implanted in the STN, seven bilaterally and two unilaterally (left). Ten were bilaterally implanted in the cZi. Postoperative examinations were made off and on stimulation. All patients received simultaneous L-dopa treatment in all conditions. For a series of plosives extracted from a reading passage, absolute and relative measures of duration of frication and amplitude of plosive release were compared between conditions within each treatment group. RESULTS Relative duration of frication increased in voiceless plosives in the on stimulation condition in cZi patients. Similar trends were observed across the data set. Duration of pre-release frication and the release peak prominence increased in voiceless plosives on stimulation for both groups. CONCLUSIONS The increased release prominence suggests that patients achieved a stronger closure gesture due to DBS, but that the increased energy available resulted in increased frication.
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| 16. |
- Karlsson, Fredrik, 1975-, et al.
(author)
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Control of phonatory onset and offset in Parkinson patients following deep brain stimulation of the subthalamic nucleus and caudal Zona Incerta
- 2012
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In: Parkinsonism & Related Disorders. - : Elsevier. - 1353-8020 .- 1873-5126. ; 18:7, s. 824-827
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Journal article (peer-reviewed)abstract
- Laryngeal hypokinesia is a common symptom in Parkinson’s disease (PD) that affects quality of life. Deep brain stimulation (DBS) is well recognized as a complementary method for treatment of motor symptoms in PD but the outcomes on patients’ control over phonatory alternation have yet not been clearly elucidated. The present study examined the effect of subthalamic nucleus STN-DBS (n=8, aged 51-72 yrs; median=63 yrs) and caudal Zona incerta cZi-DBS (n=8,aged 49-71 yrs; median=61 yrs) on control of onset and offset of phonation in connected speech. The patients were evaluated in a preoperatively (Med ON, 1.5 times the ordinary Levodopa dose) and 12 months postoperatively (Med ON, ordinary Levodopa dose). The results provided evidence of a progressive reduction in the ability to manifest alternations between voicing and voiceless states in a reading task. Mean proportion produced with inappropriate voicing increased from 47.6% to 55.3% and from 62.9% to 68.6% of the total duration for the two groups of patients between Pre-op and Post-op, Stim OFF evaluations. The medial and final parts of the fricative were more affected than the initial part, indicating an increased voicing lead into the following vowel. We propose that this reduction in phonatory control is be due to either progression of the disease, an effect of reduced Levodopa dosage or a microlesional effect. Patients’ proficiency in alternating between voiced and voiceless states in connected speech remained unaffected by both STN-DBS and cZi-DBS.
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| 17. |
- Karlsson, Fredrik, 1975-, et al.
(author)
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Deep brain stimulation of caudal zona incerta and subthalamic nucleus in patients with Parkinson’s disease : effects on diadochokinetic rate
- 2011
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In: Parkinson's Disease. - : Hindawi Publishing Corporation. - 2090-8083 .- 2042-0080. ; 2011, s. 605607-
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Journal article (peer-reviewed)abstract
- The hypokinetic dysarthria observed in Parkinson's disease (PD) affects the range, speed, and accuracy of articulatory gestures in patients, reducing the perceived quality of speech acoustic output in continuous speech. Deep brain stimulation (DBS) of the subthalamic nucleus (STN-DBS) and of the caudal zona incerta (cZi-DBS) are current surgical treatment options for PD. This study aimed at investigating the outcome of STN-DBS (7 patients) and cZi-DBS (7 patients) in two articulatory diadochokinesis tasks (AMR and SMR) using measurements of articulation rate and quality of the plosive consonants (using the percent measurable VOT metric). The results indicate that patients receiving STN-DBS increased in articulation rate in the Stim-ON condition in the AMR task only, with no effect on production quality. Patients receiving cZi-DBS decreased in articulation rate in the Stim-ON condition and further showed a reduction in production quality. The data therefore suggest that cZi-DBS is more detrimental for extended articulatory movements than STN-DBS.
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| 18. |
- Karlsson, Fredrik, 1975-, et al.
(author)
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Pitch variability in patients with Parkinson’s disease : effects of deep brain stimulation of caudal zona incerta and subthalamic nucleus
- 2013
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In: Journal of Speech, Language and Hearing Research. - : American Speech-Language-Hearing Association. - 1092-4388 .- 1558-9102. ; 56:1, s. 150-158
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Journal article (peer-reviewed)abstract
- Objective The purpose of the present study was to examine the effect of deep brain stimulation (DBS) of the subthalamic nucleus (STN) and the caudal zona incerta (cZi) pitch characteristics of con- nected speech in patients with Parkinson’s disease (PD).Methods Sixteen patients were evaluated preoperatively and 12 months after DBS surgery. Eight pa- tients were implanted in the STN (aged 51-72 yrs; xC=63 yrs). Six received bilateral implanta- tion and two unilateral (left) implantation. Eight patients were bilaterally implanted in the cZi (aged 49-71 yrs; xC=60.8 yrs). Preoperative assessments were made after an L-Dopa challenge (approximately 1.5 times the ordinary dose). All postoperative examinations were made off and on stimulation, with a clinically optimized dose of L-dopa. Measurements of pitch range and var- iability were obtained from each utterance in a recorded read speech passage.Results Pitch range and coefficient of variation showed an increase in patients under STN-DBS. Patients under cZi-DBS showed no significant effects of treatment on investigated pitch properties.Conclusions STN-DBS was shown to increase pitch variation and range. The results provided no evidence of cZi-DBS having a beneficial effect on PD patients’ pitch variability.
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| 19. |
- Kulneff, Linda, et al.
(author)
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Deep brain stimulation : effects on swallowing function in Parkinson's disease
- 2013
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In: Acta Neurologica Scandinavica. - Hoboken : Wiley-Blackwell. - 0001-6314 .- 1600-0404. ; 127:5, s. 329-336
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Journal article (peer-reviewed)abstract
- Objective: In patients with Parkinson’s disease (PD), deep brainstimulation of the subthalamic nucleus (STN DBS) is well recognizedin improving limb function, but the outcome on swallowing functionhas rarely been studied. The aim of this work was to evaluate theeffect of STN DBS on pharyngeal swallowing function in patientswith PD using self-estimation and fiberoptic endoscopic evaluation ofswallowing.Methods: Eleven patients (aged 41–72, median 61 years)were evaluated preoperatively and at 6 and 12 months after STN DBSsurgery. All patients were evaluated with self-estimation on a visualanalogue scale, and eight of them with a fiberoptic endoscopicexamination with a predefined swallowing protocol includingRosenbek’s Penetration-Aspiration Scale, Secretion Severity Scale,preswallow spillage, pharyngeal residue, and pharyngeal clearance.Results: The self-assessments of swallowing function revealed asubjective improvement with STN DBS stimulation, whereas the datafrom the swallowing protocol did not show any significant effect ofthe STN DBS treatment itself. The prevalence of aspiration was notaffected by the surgery.Conclusions: The results show thatswallowing function was not negatively affected by STN DBS and therisk of aspiration did not increase. Self-estimation of swallowingfunction showed a subjective improvement due to stimulation.
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| 20. |
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| 21. |
- Louise, Johansson, et al.
(author)
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Word-level intelligibility after caudal zona incerta stimulation for Parkinson’s disease
- 2014
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In: Acta Neurologica Scandinavica. - : Wiley-Blackwell. - 0001-6314 .- 1600-0404. ; 130:1, s. 27-33
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Journal article (peer-reviewed)abstract
- Objectives – To investigate the effect of caudal zona incerta-deep brain stimulation (cZi-DBS) on word-level speech intelligibility in patients with Parkinson’s disease, under both an optimal listening condition and a simulated more naturalistic listening condition.Materials and methods – Spoken single words were extracted from read samples collected from 10 bilaterally implanted patients with PD pre- and post-cZi-DBS. Intelligibility was assessed through a transcription task performed by 32 naive listeners under two listening conditions: (i) with low-amplitude conversational speech added as background and (ii) with no added background noise. The listeners′ responses were scored in terms of agreement with the intended words.Results – Post-operatively, the total intelligibility score was significantly lower when cZi stimulation was switched on compared with off, for both listening conditions (with and without added background noise). Intelligibility was also significantly lower on stimulation compared with preoperative recordings, but only when assessed in the listening condition without background noise. The listening condition with added background noise resulted in significantly lower intelligibility scores compared with the no added noise condition for all stimulation conditions.Conclusions – The results of this study indicate that cZi-DBS in patients with PD can be detrimental to word-level speech intelligibility.
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| 22. |
- Lundgren, Sofie, et al.
(author)
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Deep brain stimulation of caudal zona incerta and subthalamic nucleus in patients with Parkinson’s disease : effects on voice intensity
- 2011
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In: Parkinson's Disease. - : Hindawi Publishing Corporation. - 2090-8083 .- 2042-0080. ; 2011, s. 658956-
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Journal article (peer-reviewed)abstract
- Deep brain stimulation of the subthalamic nucleus (STN-DBS) in patients with Parkinson’s disease (PD) affects speech in small, inconsistent ways. However, voice intensity generally increases. Recently the caudal zona inserta (cZi) has been investigated as an alternate target in DBS treatment of PD. The effects of cZi-DBS on voice intensity have not yet been investigated. The aim of this study was to compare the voice intensity effects of cZi-DBS and STN-DBS in PD patients. Voice intensity during reading and intensity decay during rapid syllable repetition were measured for eight STN-DBS and eight cZi-DBS patients in a pre-surgical baseline and then on- and off-stimulation 12 months after surgery. Voice intensity on-stimulation was larger than off-stimulation for the STN-DBS patients, but smaller for the cZi-DBS patients. There were no significant changes in intensity decay. The results suggest that cZi and STN are involved differently in neuromuscular control of the speech respiratory subsystem.
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| 23. |
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| 24. |
- Sundstedt, Stina, 1988-, et al.
(author)
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Swallowing function in Parkinson’s patients following Zona Incerta deep brain stimulation
- 2012
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In: Acta Neurologica Scandinavica. - : John Wiley & Sons. - 0001-6314 .- 1600-0404. ; 126:5, s. 350-356
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Journal article (peer-reviewed)abstract
- Objective The purpose of the present study was to examine if there was a negative effect of caudal Zona Incerta deep brain stimulation (cZI DBS) on pharyngeal swallowing function in Parkinson’s patients (PD). There are no former reports on swallowing and cZI DBS.Methods Eight patients (aged 49 to 71 years; median 62) were evaluated pre- and postoperatively, at six and 12 months after DBS surgery. Evaluation tools were Fiberoptic Endoscopic Evaluation of Swallowing examinations and patients’ self-assessments of the swallowing function including a visual analogue scale and quality of life related questions. The swallowing protocol included Rosenbeck’s Penetration-Aspiration Scale, Secretion Severity Scale and parameters for pre-swallow spillage, pharyngeal residue and pharyngeal clearance.Results There was no clear-cut effect of neurostimulation postoperatively at six and 12 months on any of the swallowing parameters except for pre-swallow spillage which was slightly worsened in the stimulation on condition 12m postoperatively. The answers to the self assessment questions did not vary significantly.Conclusions The effect of the stimulation on swallowing function varied among individuals but the overall outcome was that cZI DBS did not seem to have a negative influence on swallowing function in the eight patients studied.
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| 25. |
- Ballard, Kirrie J., et al.
(author)
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Developmental Trajectory for Production of Prosody : Lexical Stress Contrastivity in Children Ages 3 to 7 Years and in Adults
- 2012
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In: Journal of Speech, Language and Hearing Research. - : American Speech-Language-Hearing Association. - 1092-4388 .- 1558-9102. ; 55:6, s. 1822-1835
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Journal article (peer-reviewed)abstract
- Purpose: Accurate production of lexical stress within English polysyllabic words is critical for intelligibility and is affected in many speech-language disorders. However, models of speech production remain underspecified with regard to lexical stress. In this study, the authors report a large-scale acoustic investigation of lexical stress production in typically developing Australian English-speaking children ages 3-7 years (n = 73) compared with young adults (n = 24).Method: Participants named pictures of highly familiar strong-weak and weak-strong polysyllabic words. Of 388 productions, 325 met criteria for acoustic measurement. Relative vowel duration, peak intensity, and peak f(0) over the first two syllables were measured.Result: Lexical stress was marked consistently by duration and intensity but not f(0). Lexical stress on strong-weak words was adultlike by 3 years. All 3 measures showed significant differences between adults and children for weak-strong words still present at 7 years.Conclusion: Our findings suggest that protracted development of weak-strong stress production reflects physiological constraints on producing short articulatory durations and rising intensity contours. Findings validate treatment that is centered on strong-weak stress production for children >= 3 years with dysprosody. Although intervention for the production of weak-strong words may be initiated before age 7 years, reference to normative acoustic data is preferable to relying on perceptual judgments of accuracy.
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| 26. |
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| 27. |
- Brunnegård, Karin, et al.
(author)
-
Comparison between perceptual assessments of nasality and nasalance scores
- 2012
-
In: International journal of language and communication disorders. - : Wiley-Blackwell. - 1368-2822 .- 1460-6984. ; 47:5, s. 556-566
-
Journal article (peer-reviewed)abstract
- Background: There are different reports of the usefulness of the Nasometer™ as a complement to listening, often as correlation calculations between listening and nasalance measurements. Differences between findings have been attributed to listener experience and types of speech stimuli.Aims: To compare nasalance scores from the Nasometer with perceptual assessments, for the same and different Swedish speech stimuli, using three groups of listeners with differing levels of experience in judging speech nasality. Methods & Procedures: To compare nasalance scores and blinded listener ratings of randomized recordings using three groups of listeners and two groups of speakers. Speakers were either classified as having hypernasal speech or speech with typical speech resonance. Listeners were speech-language pathologists (SLPs) working predominantly with resonance disorders, other SLPs and untrained listeners.Outcomes & Results: Correlations (r(s) ) between hypernasality ratings and nasalance scores for each listener group and speech stimuli were calculated. For both groups of SLPs all correlations between perceptual ratings and nasalance scores were significant at p= 0.01. The correlations between the nasalance scores and ratings by listeners in the SLP groups were higher than those for the untrained listener group regardless of stimulus type. Post-hoc Mann-Whitney U-tests showed that the only difference that was significant was expert SLP group versus untrained listener group. Secondly, correlations between perceptual ratings and oral stimulus nasalance scores were higher when the perceptual ratings were based on spontaneous speech rather than on the oral stimulus. However, a Wilcoxon signed rank test showed that the difference was not significant. A third finding was that correlations between oral stimulus nasalance scores and perceptual scores were higher than those between mixed stimulus nasalance scores and perceptual scores. A Wilcoxon signed rank test showed that the difference was significant.Conclusions & Implications: The Nasometer might be useful for the SLP with limited experience in assessing resonance disorders in differentiating between hyper- and hyponasality. With listener reliability for ratings of hypernasality still being an issue, the use of a nasalance score as a complement to the perceptual evaluation will also aid the expert SLP. It will give an alternative way of quantifying speech resonance and might help in especially hard to judge cases.
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| 28. |
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| 29. |
- Brunnegård, Karin, 1973-
(author)
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Evaluation of nasal speech : a study of assessments by speech-language pathologists, untrained listeners and nasometry
- 2008
-
Doctoral thesis (other academic/artistic)abstract
- Excessive nasal resonance in speech (hypernasality) is a disorder which may have negative communicative and social consequences for the speaker. Excessive nasal resonance is often associated with cleft lip and palate, velopharyngeal impairment, dysarthria or hearing impairment. Evaluation of hypernasality has proved to be a challenge in the clinic and in research. There are questions regarding the accuracy and reliability of auditory perceptual evaluations of nasal speech, and whether instrumental measures can be used to improve the reliability of clinical evaluation. There is also the question of whether clinical evaluation reflects the impact of hypernasality in a speaker’s everyday life. The purpose of this thesis was to evaluate the extent of reliability problems connected with auditory perceptual assessment of nasality in speech, to explore whether they might interfere with treatment decisions or have an impact in the everyday life of patients, and whether they can be effectively diminished by the use of nasometry. Speakers with cleft lip and palate or velopharyngeal impairment formed the basis of the clinical population used in this study. Speech samples from 52 of these speakers, along with samples from a reference population of 21 speakers who did not have cleft palate, velopharyngeal impairment or speech disorders were used in perceptual evaluation tasks. Fourteen speakers from the clinical population and 11 from the reference population also underwent nasometric evaluation. A further reference population of 220 children from three Swedish cities, whose ages were consistent with those used for clinical checks of children born with cleft palate were assessed with nasometry to establish normative data for the Nasometer™. Perceptual speech assessments were conducted on hyper- and hyponasality, as well as audible nasal air emission and/or nasal turbulence, using 5-point ordinal scales. Listeners were SLPs experienced in the evaluation of cleft palate speech, non-expert SLPs and untrained listeners. Listening assessments were performed from audio recorded speech samples assembled in random order. Nasometry measures were made on three speech passages each with specific phonetic content, using the Nasometer™, model II. Perceptual evaluation Results showed that for hypernasality assessment, 15% of hypernasality assessments had disagreements between expert SLPs that were potentially important for clinical decisions, as did 6% of assessments for audible nasal air emission and/or nasal turbulence. For nasality problems, a comparison of expert and untrained listeners showed that they generally agreed on which speakers were hypernasal and on the ranking of nasal speakers. All speakers that had been rated with moderate to severe hypernasality by expert listeners were considered by the untrained listeners as having a serious enough speech disorder to call for intervention. However, in the case of audible nasal air emission and/or nasal turbulence the expert listeners were more prone to notice this feature than the untrained listeners. Instrumental evaluation The development of normative values for the three Swedish passages for the NasometerTM (comparable to normative values in other languages) has provided a basis for use of instrumental measures in Swedish clinics, oral sentences mixed sentences nasal sentences. The measures showed no significant differences due to city, gender or age within an age range of 4-10 years. When nasometry measures were compared with perceptual evaluation of speech samples from the same speakers, all correlations were moderate to good for expert SLPs and non-expert SLPs. The difference between correlations was significantly higher for expert SLPs than for untrained listeners. Reliability figures for perceptual assessments for expert SLP listeners indicated that there were some cases where lack of reliability could affect clinical decision making. However, in the main, judgements of nasality problems made by clinicians had everyday validity. They reflected the impressions of the everyday listener, especially in regard to the need for intervention. The study also indicates that now that Swedish norms are available, the Nasometer™ might be useful as a complement to auditory perceptual clinical speech assessments in Swedish cleft palate clinics in order to improve reliability of clinical assessment.
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| 30. |
- Brunnegård, Karin, et al.
(author)
-
Normative data on nasalance scores for Swedish as measured on the Nasometer™ II : influence of regional dialect, gender and age
- 2009
-
In: Clinical linguistics and phonetics. - : Informa UK Limited. - 1368-2822 .- 0269-9206 .- 1464-5076. ; 23:1, s. 58-69
-
Journal article (peer-reviewed)abstract
- This study was conducted to establish normative nasalance values for Swedish speaking children as measured with the Nasometer™ II, and to investigate differences due to regional dialect, gender, and age. Two hundred and twenty healthy children aged 4-5, 6-7, and 9-11 years were included. Group mean nasalance scores for four speech stimuli were calculated and compared. There were no significant differences due to dialect or gender for children in the study. For age there was a significant difference on nasal sentences between the youngest group of children and the other two groups, age 4-5 vs age 6-7 (t = -2.844, p = .006) and for age 4-5 vs age 9-11 (t = -2.888, p = .005). The results from this study have both clinical significance for Swedish SLPs working with resonance disorders, and theoretical significance for linguists studying features of dialects and languages.
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| 31. |
- Brunnegård, Karin, et al.
(author)
-
Untrained listeners’ ratings of speech disorders in a group with cleft palate : a comparison with speech and language pathologists’ ratings
- 2009
-
In: International journal of language and communication disorders. - : John Wiley & Sons. - 1368-2822 .- 1460-6984. ; 44:5, s. 656-674
-
Journal article (peer-reviewed)abstract
- Background: Hypernasal resonance, audible nasal air emission and/or nasal turbulence, and articulation errors are typical speech disorders associated with the speech of children with cleft lip and palate. Several studies indicate that hypernasal resonance tends to be perceived negatively by listeners. Most perceptual studies of speech disorders related to cleft palate are carried out with speech and language pathologists as listeners, whereas only a few studies have been conducted to explore how judgements by untrained listeners compare with expert assessments. These types of studies can be used to determine whether children for whom speech and language pathologists recommend intervention have a significant speech deviance that is also detected by untrained listeners.Aims: To compare ratings by untrained listeners with ratings by speech and language pathologists for cleft palate speech.Methods & Procedures: An assessment form for untrained listeners was developed using statements and a five-point scale. The assessment form was tailored to facilitate comparison with expert judgements. Twenty-eight untrained listeners assessed the speech of 26 speakers with cleft palate and ten speakers without cleft in a comparison group. This assessment was compared with the joint assessment of two expert speech and language pathologists.Outcomes & Results: Listener groups generally agreed on which speakers were nasal. The untrained listeners detected hyper- and hyponasality when it was present in speech and considered moderate to severe hypernasality to be serious enough to call for intervention. The expert listeners assessed audible nasal air emission and/or nasal turbulence to be present in twice as many speakers as the untrained listeners who were much less sensitive to audible nasal air emission and/or nasal turbulence.Conclusions & Implications: The results of untrained listeners' ratings in this study in the main confirm the ratings of speech and language pathologists and show that cleft palate speech disorders may have an impact in the everyday life of the speaker.
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| 32. |
- Doorn, Jan van, et al.
(author)
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Influence of speech task and utterance length on the measurement of pitch variability in the speech of Parkinson's disease patients after deep brain stimulation
- 2013
-
Conference paper (other academic/artistic)abstract
- Parkinson’s disease (PD) affects patients voice characteristics, reducing pitch variability compared to normal controls (1,2). Previous reports have shown an increase in pitch variability due to deep brain stimulation (DBS) of the Subthalamic nucleus (STN) (3). For patients stimulated in caudal zona incerta (cZi), the results indicate no effect on pitch variability in a read speech task{Karlsson:2012jr}.The present study aimed at investigating the effects of speech task (spontaneous or read speech) and the lenght of the utterance on overall measures of pitch variability observed in DBS-treated patients. Ten patients treated with STN-DBS and ten patients treated with cZi-DBS were included in this prospective study.Utterances produced sponatenously and produced during readings of a standard passage were compared in terms of treatment effects in pitch variability due to STN-DBS and cZi-DBS (Stim OFF and Stim ON recordings made 1,5 hour apart, all in Med ON) 6 and 12 months after operation. The results indicate that pitch variability is affected differently by STN-DBS and cZi-DBS depending on speech task and utterance length. In short utterances (<10 words), an increase in pitch variability is observed for both treatment groups and both speech tasks. For longer utterances, however, a more diverse effect of treatment and speech task is observed. The results therefore suggest that spech task and characteristics of thate utterance should be carefully considered when drawing conclusions on the overall effect of DBS on pitch variability.1. Jiménez-Jiménez FJ, Gamboa J, Nieto A, Guerrero J, Ortí-Pareja M, Molina JA, et al. Acoustic voice analysis in untreated patients with Parkinson's disease. Parkinsonism Relat. Disord. 1997 Apr;3(2):111–6. 2. Holmes RJ, Oates JM, Phyland DJ, Hughes AJ. Voice characteristics in the progression of Parkinson’s disease. International Journal of Language & Communication Disorders. 2000;35(3):407–18. 3. Dromey C, Kumar R, Lang AE, Lozano AM. An investigation of the effects of subthalamic nucleus stimulation on acoustic measures of voice. Mov. Disord. 2000;15(6):1132–8.
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| 33. |
- Eklund, Elisabeth, 1988-, et al.
(author)
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Perceived articulatory precision in patients with Parkinson’s disease after deep brain stimulation of subthalamic nucleus and caudal zona incerta
- 2015
-
In: Clinical Linguistics & Phonetics. - : Informa UK Limited. - 0269-9206 .- 1464-5076. ; 29:2, s. 150-166
-
Journal article (peer-reviewed)abstract
- The effect of deep brain stimulation (DBS) of the subthalamic nucleus (STN) and caudal zona incerta (cZi) on speech articulation in patients with Parkinson’s disease (PD) was investigated. Read speech samples were collected from nine patients with STN-DBS and ten with cZi-DBS. The recordings were made preoperatively and 12 months postoperatively with stimulator on and off (on medication). Blinded, randomized, repeated perceptual assessments were performed on words and isolated fricatives extracted from the recordings to assess 1) overall articulatory quality ratings, 2) frequency of occurrence of misarticulation patterns, and 3) fricative production. Statistically significant worsening of articulatory measures on- compared with off-stimulation occurred in the cZi-DBS group, with deteriorated articulatory precision ratings, increased presence of misarticulations (predominately altered realizations of plosives and fricatives) and a reduced accuracy in fricative production. A similar, but not significant, trend was found for the STN-DBS group.
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| 34. |
- Eriksson, Erik J, 1978-, et al.
(author)
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Detection of imitated voices : who are reliable earwitnesses?
- 2010
-
In: The international journal of speech language and the law. - London : Equinox Publishing. - 1748-8885 .- 1748-8893. ; 17:1, s. 25-44
-
Journal article (peer-reviewed)abstract
- Factors affecting an individual's ability to identify people aurally are of forensic importance. This paper investigates how topic, dialect, gender, age, and hearing status affect detection of an imitated voice. Two imitations of the same person, but on different topics, were used as familiarization voices. One topic was associated with this person, and the other was not. Using discrimination sensitivity (d-prime) it was found that topic had a significant impact on d', as did age (but only when the topic was not associated with the imitated person). Dialect, gender and hearing status were not significant. The older group of listeners was less convinced by the imitations and in particular the one not associated with the person being imitated. These results imply that the validity of earwitness evidence is negatively affected by age and topic.
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| 35. |
- James, Deborah G H, et al.
(author)
-
Patterns of consonant deletion in typically developing children aged 3 to 7 years.
- 2008
-
In: International journal of speech-language pathology. - : Informa UK Limited. - 1754-9507 .- 1754-9515. ; 10:3, s. 179-92
-
Journal article (peer-reviewed)abstract
- Children with and without speech, language and/or literacy impairment, delete consonants when they name pictures to elicit single words. Consonant deletion seems to be more frequent in long words (words of three or more syllables) than in short words (words of one or two syllables). However, it may be missed in long words because they are not routinely assessed and, even if they are, there is little normative data about them. The study aims were (1) to determine if a relationship exists between consonant deletion and the number of syllables in words, (2) delimit variation in the numbers of children using it, its frequency of occurrence and the words it affects and (3) to discuss the application of these data to clinical practice. The participants were 283 typically developing children, aged 3;0 to 7;11 years, speaking Australian English with proven normal language, cognition and hearing. They named pictures, yielding 166 selected words that were varied for syllable number, stress and shape and repeatedly sampled all consonants and vowels of Australian English. Almost all participants (95%) used consonant deletion. Whilst a relationship existed between consonant deletion frequency and the number of syllables in words, the syllable effect was interpreted as a proxy of an interaction of segmental and prosodic features that included two or more syllables, sonorant sounds, non-final weak syllables, within-word consonant sequences and/or anterior-posterior articulatory movements. Clinically, two or three deletions of consonants across the affected words may indicate typical behaviour for children up to the age of 7;11 years but variations outside these tolerances may mark impairment. These results are further evidence to include long words in routine speech assessment.
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| 36. |
- James, Deborah G H, et al.
(author)
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The contribution of polysyllabic words in clinical decision making about children's speech.
- 2008
-
In: Clinical Linguistics & Phonetics. - : Informa UK Limited. - 0269-9206 .- 1464-5076. ; 22:4-5, s. 345-53
-
Journal article (peer-reviewed)abstract
- Poor polysyllabic word (PSW) production seems to mark paediatric speech impairment as well as impairment in language, literacy and phonological processing. As impairment in these domains may only manifest in PSWs, PSW production may provide unique information that is often excluded from clinical decision making because insufficient PSWs are included in speech tests. A 5-stage model of PSW acquisition is described. The model, grounded in optimality theory, expresses a reciprocal relationship between the relaxation of markedness constraints and the contraction of faithfulness constraints from 12 months of age to adolescence. The markedness constraints that persist to the age of 7;11 years are associated with non-final weak syllables and within-word consonant sequences. Output changes are argued to reflect increasing specification of phonological representations with age, liberating information for motor planning and execution, resulting in increasingly accurate output. The clinical implications of PSWs in assessment and therapy are discussed.
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| 37. |
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| 38. |
- Karlsson, Fredrik, 1975-, et al.
(author)
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Applying the Vowel Formant Dispersion (VFD) method to the study of reduced or alterered vowel productions
- 2012
-
Conference paper (other academic/artistic)abstract
- Formant centre frequencies are regularly used as acoustic measure of vowel quality because of the well established correlation between them and properties of vowel production(Fant, 1960). While it is recognised that it is important transform formant frequencies, as measured from the spectrogram, into relevant psychoacoustic scales when addressing issues of vowel perception, production studies are still largely based on the the raw, Hz-scaled, formant measurements. As a consequence, systematic studies of vowel articulation proficiency due to clinical conditions or effects of treatment are not easily afforded. A number of derived measures have been proposed to capture whole-system effect of vowel production. Previous research has primarily used the calculated total area of formants measured from either [a], [u], [i] and [æ] or only [a], [u] and [i] productions, joined together to form a quadrilateral or a triangle (Vowel space area, VSA)(Kent & Kim, 2003). In the reduced articulatory range of hypokinetic dysarthria, VSA is expected to be reduced by the dysarthria, and increased due to successful treatment the patient’s articulatory range. However, VSA has been proposed to be not powerful enough to capture effects on vowel articulation found specifically in patients with Parkinson’s disease (PD), and therefore not able to establish treatment effects.Two alternative measures have been proposed previously that are more focused towards specifically towards finding expansion and reductions in vowel spaces, the Vowel articulation index (VAI)(Roy, Nissen, Dromey, & Sapir, 2009) or Formant Centralization Ratio (FCR)(Sapir, Ramig, Spielman, & Fox, 2010). Both VAI and FCR has been shown to be able to establish significant reductions vowel articulation due to PD. Similar to VSA, however, the VAI and FCR measures do not given any detailed insight into the nature of the change in articulation. Further, all three measures reduces all obtained vowel formant measurements into a single metric, resulting in a substantial loss of statistical power and a considerable reduction in quality of intra-speaker models of articulatory proficiency. In response to the problematic properties of previous metrics, a revised view of formant frequencies more suitable for studies of changes in vowel articulation has recently been outlined, along with a new metric (Vowel Formant Dispersion, VFD). The VFD view of vowel formants are more closely connected to properties of vowel articulation and therefore affords more more detailed interpretations to be drawn concerning speakers’ production proficiency and offers increased reliability of within speaker estimates of this proficiency. This paper presents a detailed view of how VFD may applied to clinical populations where vowel production is affected by the condition (e.g. hypokinetic dysarthria) or where production should be affected (e.g. transexual patients or in successful treatment of dysarthric patients). It will be shown that most aspects of the study of vowel articulation proficiency will be significantly enhanced by the VFD method.
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| 39. |
- Karlsson, Fredrik, 1975-, et al.
(author)
-
Automatic acquisition of jitter and shimmer measurements across large sets of sustained vowel productions
- 2012
-
Conference paper (other academic/artistic)abstract
- Measurements of jitter and shimmer are frequently employed to quantify laryngeal control and stability during voice production in patients(1-3). Accurate estimates of jitter and shimmer may be obtained from acoustic recordings of sustained vowels produced by patients using computer software implementing algorithms for their extraction (e.g. Praat(4) or MDVP(5)). The jitter and shimmer algorithms do not, in themselves, exclude non-stable productions and are influenced by the inclusion of silence in the analysed intervals. As a consequence, reliable measurements of jitter and shimmer are made by manually opening each sound file and selecting an interval for the computations. The current paper proposes an alternative approach to afford a more efficient estimation of jitter and shimmer across a large set of sustained vowel recordings. Using information readily available in the acoustic signal and a combination of algorithms already available within the Praat program, a reliable method for automatic processing of only the sustained vowel in each recording of a large corpus is outlined. The method further affords the acquisition of multiple, repeatable, measurements of jitter and shimmer for sub-intervals of the vowel’s duration (applying more than one algorithm), which additionally provides information concerning the reliability of the jitter or shimmer estimates for a specific vowel production. Comparisons with manually obtained measurements are made for the purpose of validation of the segmentation method.
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| 40. |
- Karlsson, Fredrik, et al.
(author)
-
Då or Tå, Pår or Bår - Seeing is believing!
- 2003
-
In: Proceeding of the 15th International Congress of Phonetic Sciences.
-
Conference paper (other academic/artistic)abstract
- Several acoustic properties of plosives have been established as correlates of voicing contrast, including voice onset time (VOT), F1 cut-back, aspiration duration and initial F1 and F2 transition. Therefore, acquisition of the voicing contrast for plosives could be viewed as gaining the ability to combine interacting acoustic cues in an adult-like manner, resulting in a large number of possible developmental routes. The presented investigation examined initial plosives produced by one child from ages 18¿31 months that had been judged as voiced in an auditory analysis. The results show that some perceptually voiced and unaspirated plosives (elicited using voiceless targets) were produced with VOT values within the range of voiceless plosives for adult speakers of Swedish, and also had increased duration of high frequency, aperiodic friction after plosive release. It was conjectured that the child was attempting a voicing contrast by using increased VOT and increased duration of aperiodic friction that were not perceptible to adult listeners.
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| 41. |
- Karlsson, Fredrik, 1975-, et al.
(author)
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Letter to the Editor
- 2012
-
In: Journal of Voice. - : Elsevier. - 0892-1997 .- 1873-4588. ; 26:5
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Journal article (other academic/artistic)
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| 42. |
- Karlsson, Fredrik, 1975-, et al.
(author)
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Treatment effects in voice onset time of plosives associated with deep brain stimulation of the subthalamic nucleus and the caudal zona incerta
- 2012
-
In: Journal of medical speech-language pathology. - : Delmar Cengage Learning. - 1065-1438. ; 20:4, s. 65-69
-
Journal article (peer-reviewed)abstract
- The present study investigated the effect of deep brain stimulation (DBS) of the subthalamic nucleus (STN) and the caudal zona inserta (cZi) on motor control and coordination in plosives. A total of 2520 plosive productions, recorded during production of alternate motion rate and sequential motion rate tasks, were measured for voice onset time (VOT) when measurement was possible. Failed measurements were classified by the underlying cause. The resulting data were analyzed separately for each place of articulation of the intended plosive and compared with the articulatory properties of plosives not meeting the requirements for VOT measurement. The results showed no consistent overall stimulation effect in VOT regardless of place of articulatory closure. Furthermore, no overall pattern concerning the distribution of factors causing failures to measure VOT was observed. Instead, the results suggest a more complex interaction among place of articulation, speech task, and stimulation target in the determination of treatment effects of DBS in patients with Parkinson's disease (PD). The results further suggest that VOT may not provide a robust estimate of treatment effects in articulatory proficiency related to plosive production in patients with PD.
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| 43. |
- Karlsson, Fredrik, 1975-, et al.
(author)
-
Vowel formant dispersion as a measure of articulation proficiency
- 2012
-
In: Journal of the Acoustical Society of America. - : Acoustical Society of America (ASA). - 0001-4966. ; 132:4, s. 2633-2641
-
Journal article (peer-reviewed)abstract
- The articulatory range of a speaker has previously been estimated by the shape formed by first and second formant measurements of produced vowels. In a majority of the currently available metrics, formant frequency measurements are reduced to a single estimate for a condition, which has adverse consequences for subsequent statistical testing. Other metrics provide estimates of size of vowel articulation changes only, and do not provide a method for studying the direction of the change. This paper proposes an alternative approach. Vowel formant frequencies are re-defined as vectors originating from a defined center point of the vowel space fixed to a basic three-vowel frame. The euclidian length of the vectors, the Vowel Formant Dispersion (VFD), can be compared across conditions for evidence of articulatory expansions or reductions across conditions or speaker groups. Further, the angle component of the vowel vectors allows for analyses of direction of the reduction or expansion. Based on the range of investigations afforded by the VFD metric, and simulation experiments that compare its statistical properties with those of other proposed metrics, it is argued that the VFD procedure offers an enhanced view of vowel articulation change over rival metrics.
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| 44. |
- Lohmander, Anette, et al.
(author)
-
Kommunikations- och sväljstörningar genom hela livet : ett logopediskt ståndpunktsdokument
- 2017
-
Reports (other academic/artistic)abstract
- Den forskning som bedrivs inom logopedi i Sverige idag spänner över ett brett spektrum av medfödda, utvecklingsrelaterade och förvärvade kommunikationsstörningar på grund av röst-, tal- och språksvårigheter samt sväljstörningar. Precis som i andra länder pågår en snabb utveckling både mot en breddning av det urval av områden som det forskas kring och ett ökat fokus på nationellt samarbete. Även om de framsteg som görs inom respektive fält kan mätas genom de forskningsrapporter som publiceras av respektive forskargrupper, finns det ett behov av att granska vilka forskningsinsatser som bedrivs jämte det demografiska sammanhanget. I detta ståndpunktsdokument ger vi en översikt över logopediämnet och den forskning som bedrivs i Sverige. I en kubmodell illustreras hur kommunikations- och sväljstörningar kan beskrivas. Stratifierade (per åldersintervall) uppskattningar av prevalensen av kommunikations- och sväljstörningar ges baserat på 2016 års befolkningsstruktur. Genom att presentera dessa två komponenter identifieras forskningsområden och riktningar inom logopedi som behöver ges ökad uppmärksamhet i det kommande forskningsarbetet.
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| 45. |
- Sandvik, Ulrika, 1978-, et al.
(author)
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Thalamotomy for essential tremor : a very long-term follow-up
- 2012
-
In: Open Neurosurgery Journal. - : Bentham Open. - 1876-5297. ; 5, s. 1-7
-
Journal article (peer-reviewed)abstract
- Background: DBS (deep brain stimulation) is currently the golden standard in the surgical treatment of ET (essential tremor). Despite the benefits of DBS, there remain situations where lesional surgery may provide an alternative.Objective: To perform a very long-term retrospective evaluation of thalamotomies for ET.Methods: Nine patients who underwent thalamotomy for ET during 1972–1999 (follow-up period 20.8 ± 5.2 years) were assessed with regard to tremor scores, side effects, and quality of life, as well as lesion size and location.Results: All patients had tremor recurrence, although hand function remained slightly better on the treated side than on the non-treated side. Side effects that could be attributed to the procedure were frequent and did in some cases result in a disability for the patient. Quality of life was poorer in this group than in an age-adjusted healthy population. No correlation between lesion size, location, and long-term outcome could be established.Conclusions: In this study population the benefits of thalamotomies were limited, while complications were frequent.
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| 46. |
- van Doorn, Jan, 1949-, et al.
(author)
-
An acoustic investigation of the Swedish child’s acquisition of obstruent place of articulation
- 2008
-
In: Acoustics'08 Paris : June 29 - July 4, 2008. - Paris : Société Française d'Acoustique (SFA). - 9782952110549 ; , s. 681-686
-
Conference paper (other academic/artistic)abstract
- Speech produced by children in the initial stages of development does generally not uphold as many phonetic distinctions as speech sounds produced by adults. A child's productions of different target words may therefore have similar acoustic properties and result in homonyms being perceived by the adult observer. This study presents a longitudional investigation into the development of place of articulation from non‐distinctive to distinctive productions in word‐initial obstruents produced by 22 Swedish children (aged 18 ‐ 48 months). The data was collected through monthly recordings, approximatelly one year per child. The acoustic correlates analysed were spectral diffuseness, spectral skewness and spectral tilt for plosives and spectral skewness, spectral kurtosis, spectral variance and F2 onset frequency for fricatives. The results show a developmental trend in spectral skewness that is indicative of a increasing number of acquired phonetic contrasts. Spectral tilt change, F2 onset frequency, spectral mean and spectral variance provide evicence of within‐category refinement wich is argued to be caused primarilly by advancements in motor control.
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| 47. |
- van Doorn, Jan, et al.
(author)
-
Optimizing stimulus length for clinical nasalance measures in Swedish
- 2009
-
In: Clinical Linguistics & Phonetics. - : Informa UK Limited. - 0269-9206 .- 1464-5076. ; 22:4-5, s. 355-361
-
Journal article (peer-reviewed)abstract
- Standardized passages used for speech nasalance measures may be too long for clinical use with very young or non-compliant patients. The aim of this study was to establish whether nasalance scores from shorter sections of three Swedish speech stimuli were equivalent to those from their corresponding whole stimulus. Nasalance recordings for three Swedish speech stimuli (oral, nasal and oronasal) were obtained from 29 typically developing Swedish children (7-11 years). Cumulative sentence combinations were evaluated for equivalence to their respective whole passages according to two different criteria: one based on t-testing and the other on cumulative frequencies of score differences. Results showed that shorter sequences of sentences could be considered equivalent to the whole passage for the oral and nasal stimuli, provided that the sentences were sequenced in order of increasing difference from the whole stimulus score and that those sentences with scores significantly different from the whole passage score were not included.
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| 48. |
- Zetterholm, Elisabeth, et al.
(author)
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Why Foil 4? A first look
- 2003
-
In: Proceedings from Fonetik 2003 ; Phonum 9. - 9173054305 ; 9, s. 161-164
-
Conference paper (other academic/artistic)abstract
- Recent studies have shown that ability to recognize an imitated voice is affected by topic and familiarity with the person being imitated. The signal detection methods used in those studies give no specific information about the distribution of non matching positive responses (false alarms) amongst voices used as distracters (foils). This paper shows that there was a selective listener preference for Foil 4. However, preliminary comparison of Foil 4 with the target imitated voice has not revealed conclusively any similarities in speech features that account for listeners’ preferential selection.
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