| 1. |
- Bigert, Johnny, et al.
(författare)
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Automatic Evaluation of Robustness and Degradation in Tagging and Parsing
- 2003
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Ingår i: Proceedings of the International Conference Recent Advances in Natural Language Processing 2003. - Borovets, Bulgaria.
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Konferensbidrag (refereegranskat)abstract
- We address the topic of automatic evaluationof robustness and performance degradation inparsing systems. We focus on one aspect of robustness, namely ill-formed sentences and the impact of spelling errors on the different componentsof a parsing system. We propose anautomated framework to evaluate robustness, where ill-formed and noisy data is introducedusing an automatic tool and fed to the parsingsystem. With increasing levels of noise, the performanceof a system will inevitably degrade, and the question is to what extent? The experiments show a graceful degradation in performancefor both state-of-the-art taggers usedand a Swedish shallow parser. The automatednature of the evaluation allows easy and reproducibleevaluation of the individual componentsof a parsing system.
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| 2. |
- Bigert, Johnny, et al.
(författare)
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Grammar checking for Swedish second language learners
- 2004
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Ingår i: CALL for the Nordic Languages. - Copenhagen Business School : Samfundslitteratur. - 8759311762 ; , s. 33-47
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Grammar errors and context-sensitive spelling errors in texts written by second language learners are hard to detect automatically. We have used three different approaches for grammar checking: manually constructed error detection rules, statistical differences between correct and incorrect texts, and machine learning of specific error types. The three approaches have been evaluated using a corpus of second language learner Swedish. We found that the three methods detect different errors and therefore complement each other.
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| 3. |
- Borga, Magnus, 1965-, et al.
(författare)
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A canonical correlation approach to exploratory data analysis in fMRI
- 2002
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- A computationally efficient data-driven method for exploratory analysis of functional MRI data is presented. The basic idea is to reveal underlying components in the fMRI data that have maximum autocorrelation. The tool for accomplishing this task is Canonical Correlation Analysis. The proposed method is more robust and much more computationally efficient than independent component analysis, which previously has been applied in fMRI.
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| 4. |
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| 5. |
- Carlberger, Johan, et al.
(författare)
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The development and performance of a grammar checker for Swedish : A language engineering perspective
- 2004
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Ingår i: Natural Language Engineering. - 1351-3249 .- 1469-8110. ; 1:1
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Tidskriftsartikel (refereegranskat)abstract
- This article describes the construction and performance of Granska – a surface-oriented system for grammar checking of Swedish text. With the use of carefully constructed error detection rules, written in a new structured rule language, the system can detect and suggest corrections for a number of grammatical errors in Swedish texts. In this article, we specifically focus on how erroneously split compounds and disagreement are handled in the rules. The system combines probabilistic and rule-based methods to achieve high efficiency and robustness. The error detection rules are optimized using statistics of part-of-speech bigrams and words in a way that each rule needs to be checked as seldom as possible. We have found that the Granska system with higher efficiency can achieve the same or better results than systems with conventional technology.
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| 6. |
- Domeij, Rickard, et al.
(författare)
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Different ways of evaluating a Swedish grammar checker
- 2002
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Ingår i: Proceedings of the third international conference on language resources and evaluation (LREC). ; , s. 262-267
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Three different ways of evaluating a Swedish grammar checker are presented and discussed in this article. The first evaluationconcerns measuring the program's detection capacity on five text genres. The measures (precision and recall) are often used inevaluating grammar checkers. However, in order to test and improve the usability of grammar checking software, they need to becomplemented with user-oriented methods. Consequently, the second and the third evaluations presented in the article both involveusers. The second evaluation focuses on user reactions to grammar error presentations, especially with regard to false alarms anderroneous error identification. The third and last evaluation focuses on problems in supporting users' cognitive revision processes. Italso examines user motives behind choosing to correct or not to correct problems highlighted by the program. Advantages anddisadvantages of the different evaluation methods are discussed.
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| 7. |
- Friman, Ola, 1975-, et al.
(författare)
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A Correlation Framwork For Functional Mri Data Analysis.
- 2001
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Ingår i: Proceedings of SCIA 2001. Bergen,2001. - 8299594006 ; , s. 3-9
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Konferensbidrag (refereegranskat)abstract
- A correlation framework for detecting brain activity in functional MRI data is presented. In this framework, a novel method based on canonical correlation analysis follows as a natural extension of established analysis methods. The new method shows very good detection performance. This is demonstrated by localizing brain areas which control finger movements and areas which are involved in numerical mental calculation.
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| 8. |
- Friman, Ola, et al.
(författare)
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Adaptive analysis of fMRI data
- 2003
-
Ingår i: NeuroImage. - 1053-8119 .- 1095-9572. ; 19:3, s. 837-845
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Tidskriftsartikel (refereegranskat)abstract
- This article introduces novel and fundamental improvements of fMRI data analysis. Central is a technique termed constrained canonical correlation analysis, which can be viewed as a natural extension and generalization of the popular general linear model method. The concept of spatial basis filters is presented and shown to be a very successful way of adaptively filtering the fMRI data. A general method for designing suitable hemodynamic response models is also proposed and incorporated into the constrained canonical correlation approach. Results that demonstrate how each of these parts significantly improves the detection of brain activity, with a computation time well within limits for practical use, are provided.
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| 9. |
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| 10. |
- Friman, Ola, et al.
(författare)
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Detection and detrending in fMRI data analysis
- 2004
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Ingår i: NeuroImage. - : Elsevier BV. - 1053-8119 .- 1095-9572. ; 22:2, s. 645-655
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Tidskriftsartikel (refereegranskat)abstract
- This article addresses the impact that colored noise, temporal filtering, and temporal detrending have on the fMRI analysis situation. Specifically, it is shown why the detection of event-related designs benefit more from pre-whitening than blocked designs in a colored noise structure. Both theoretical and empirical results are provided. Furthermore, a novel exploratory method for producing drift models that efficiently capture trends and drifts in the fMRI data is introduced. A comparison to currently employed detrending approaches is presented. It is shown that the novel exploratory model is able to remove a major part of the slowly varying drifts that are abundant in fMRI data. The value of such a model lies in its ability to remove drift components that otherwise would have contributed to a colored noise structure in the voxel time series.
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| 11. |
- Friman, Ola, et al.
(författare)
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Detection of neural activity in fMRI using maximum correlation modeling
- 2002
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Ingår i: NeuroImage. - : Elsevier BV. - 1053-8119 .- 1095-9572. ; 15:2, s. 386-395
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Tidskriftsartikel (refereegranskat)abstract
- A technique for detecting neural activity in functional MRI data is introduced. It is based on a novel framework termed maximum correlation modeling. The method employs a spatial filtering approach that adapts to the local activity patterns, which results in an improved detection sensitivity combined with good specificity. A spatially varying hemodynamic response is simultaneously modelled by a sum of two gamma functions. Comparisons to traditional analysis methods are made using both synthetic and real data. The results indicate that the maximum correlation modeling approach is a strong alternative for analyzing fMRI data.
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| 12. |
- Friman, Ola, 1975-, et al.
(författare)
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Detection of neural activity in functional MRI using canonical correlation analysis
- 2001
-
Ingår i: Magnetic Resonance in Medicine. - 0740-3194 .- 1522-2594. ; 45:2, s. 323-330
-
Tidskriftsartikel (refereegranskat)abstract
- A novel method for detecting neural activity in functional magnetic resonance imaging (fMRI) data is introduced. It is based on canonical correlation analysis (CCA), which is a multivariate extension of the univariate correlation analysis widely used in fMRI. To detect homogeneous regions of activity, the method combines a subspace modeling of the hemodynamic response and the use of spatial relationships. The spatial correlation that undoubtedly exists in fMR images is completely ignored when univariate methods such as as t-tests, F-tests, and ordinary correlation analysis are used. Such methods are for this reason very sensitive to noise, leading to difficulties in detecting activation and significant contributions of false activations. In addition, the proposed CCA method also makes it possible to detect activated brain regions based not only on thresholding a correlation coefficient, but also on physiological parameters such as temporal shape and delay of the hemodynamic response. Excellent performance on real fMRI data is demonstrated.
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| 13. |
- Friman, Ola, et al.
(författare)
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Emphysema Detection in CT Images
- 2002
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This paper describes a fully automatic approach for detecting emphysema in CT im ages of the lungs. The method combines an image processing step, where potential emphysematous area s are extracted, and a neural network step trained to rec
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| 14. |
- Friman, Ola, 1975-, et al.
(författare)
-
Exploratory fMRI analysis by autocorrelation maximization
- 2002
-
Ingår i: NeuroImage. - : Elsevier BV. - 1053-8119 .- 1095-9572. ; 16:2, s. 454-464
-
Tidskriftsartikel (refereegranskat)abstract
- A novel and computationally efficient method for exploratory analysis of functional MRI data is presented. The basic idea is to reveal underlying components in the fMRI data that have maximum autocorrelation. The tool for accomplishing this task is Canonical Correlation Analysis. The relation to Principal Component Analysis and Independent Component Analysis is discussed and the performance of the methods is compared using both simulated and real data.
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| 15. |
- Friman, Ola, 1975-, et al.
(författare)
-
Hierarchical temporal blind source separation of fMRI data
- 2002
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Ingår i: Proceedings of the ISMRM Annual Meeting (ISMRM'02).
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Konferensbidrag (refereegranskat)abstract
- Blind Source Separation (BSS) of fMRI data can be done both temporally and spatially. Temporal BSS of fMRI data has one fundamental problem not encountered in the spatial BSS approach. There are thousands of observed timecourses in an fMRI data set while the number of samples of each timecourse typically is less than two hundred. This re lation makes the problem of recovering the underlying temporal sources ill-posed. This contribution eliminates this problem by introducing a hierarchical approach for performing temporal BSS of fMRI data.
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| 16. |
- Friman, Ola, et al.
(författare)
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Imaging Brain Function
- 2002
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 17. |
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| 18. |
- Friman, Ola, 1975-, et al.
(författare)
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Recognizing emphysema - A neural network approach
- 2002
-
Ingår i: Pattern Recognition, 2002. Proceedings. 16th International Conference on (Volume:1). - : IEEE Computer Society. ; , s. 512-515
-
Konferensbidrag (refereegranskat)abstract
- An accurate and fully automatic method for detecting and quantifying emphysema in CT-images is presented. The method is based on an image preprocessing step followed by a neural network classifier trained to separate true emphysema from artifacts. The proposed approach is shown to be superior to an established method when applied on real patient data.
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| 19. |
- Johansson, Torsten, et al.
(författare)
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Heterotopic bone formation following internal fixation or arthroplasty for displaced femoral neck fractures: a prospective randomized study
- 2001
-
Ingår i: International Orthopaedics. - : Springer Science and Business Media LLC. - 0341-2695 .- 1432-5195. ; 25:4, s. 223-225
-
Tidskriftsartikel (refereegranskat)abstract
- One hundred hips in 99 patients of 75 years or older, with a displaced femoral neck fracture, were studied for heterotopic ossification (HO). The patients were randomized to either internal fixation or total hip arthroplasty (THA). In the THA group HO was found in 32 of 45 hips compared with 1 of 39 in the internal fixation group (P<0.0012). The frequency of HO after THA corresponds well with findings in other studies on patients receiving THA for osteoarthrosis. In cervical fractures the surgical procedure of total hip replacement seems to be a prerequisite for HO, indicating that the procedure itself is more important than the patient's age and the diagnosis. Severe symptoms due to HO were found in only one patient. HO following THA for a femoral neck fracture is of little clinical importance and prophylaxis is unnecessary.
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| 20. |
- Johansson, Torsten, et al.
(författare)
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Internal fixation versus total hip arthroplasty in the treatment of displaced femoral neck fractures
- 2000
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Ingår i: Acta Orthopaedica Scandinavica. - 0001-6470. ; 71:6, s. 597-602
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Tidskriftsartikel (refereegranskat)abstract
- 100 patients 75 years or older, with displaced femoral neck fractures, were randomly assigned to osteosynthesis with two parallel and percutaneously inserted screws (Olmed) or total hip arthroplasty (Lubinus IP). Mean age was 84 (75-101) years, 74% were women and 45% had mental dysfunction. General complications were commoner in the arthroplasty group but the mortality rates did not differ. In the osteosynthesis group, fracture complications were seen in 27/50 hips. In the arthroplasty group, dislocation was the main complication and occurred in 11/50 cases. At 3 months and after 1 year, the Harris Hip Scores were significantly better in the arthroplasty group. When mental dysfunction was present, the dislocation rate after arthroplasty was 32%, whereas the reoperation rate after osteosynthesis was 5%. The opposite pattern of complications was found in patients with normal mental function, 12% versus 60%. The 2-year mortality rate among those with mental dysfunction was 26/45, compared to 7/55 of those with normal function (p < 0.001). We conclude that total hip arthroplasty should be considered for a displaced femoral neck fracture in old patients with normal mental function and high functional demands.
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| 21. |
- Knutsson, Hans, et al.
(författare)
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En vattenbild från Vilda Västern
- 2003
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Ingår i: Svenskt Vatten. - 1651-0674. ; :2003:2, s. 50-51
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Tänk er en stad som ligger i en öken. När det blir riktigt hett kan det bli upp till 45 grader i skuggan. Medeltemperaturen på årsbasis är cirka 22 och som varmast är det i juli och augusti med 33 grader i genomsnitt. Med sådan hetta är det inte förvånansvärt att man förr i tiden dödade varandra för tillgången till vatten. Tänk er att denna stad är den snabbast expanderande staden i landet. Mellan 1960 och 2000 ökade staden med nästan 23 000 invånare/år. Idag bor där runt 1 350 000 människor. Givet dessa förutsättningar så har stadens vattenförsörjning över åren ställts in för flera utmaningar. För inte var det stadens enorma vattentillgångar som initierade denna tillväxt. Det var inte förrän luftkonditioneringen blev en allmän egendom i mitten av 1950-talet som folk fann det möjligt, för att inte säga riktigt behagligt, att bo i den s.k. Soldalen.
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| 22. |
- Knutsson, Hans, et al.
(författare)
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Förändring, stabilitet, managed competition
- 2003
-
Ingår i: RVF-nytt. - 0284-1827. ; :2003:4, s. 34-35
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Den amerikanska staden Phoenix ligger omgiven av berg i Sun Valley, Arizona. Klimatet är varmt och glest utspridda kaktusar står som eldgafflar mot skyn. Tänk på en typisk Vilda Västern-film så får du en förnimmelse av vad som kännetecknar Phoenix omgivningar. Trots ökenlika förhållanden bor där idag 1,3 miljoner invånare. Befolkningstillväxten tog fart på allvar luftkonditioneringen introducerades i början av 1950-talet och staden tillhör idag USAs snabbast växande. Under det senaste decenniet har staden lyfts fram som ett föredöme när det gäller styrning och organisation av kommunal verksamhet, åtminstone enligt de tävlingar som staden vunnit sedan den 1993 blev utsedd till ’best run city in the world’. Hur kan detta egentligen komma sig? Vi blev nyfikna och for till Phoenix, staden där avfallshantering betraktas som en kommunal kärnverksamhet och där det kostar det 21 dollar i månaden att få sitt hushållsavfall omhändertaget. Nedan kommer några nedslag om staden i stort och dess avfallshantering.
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| 23. |
- Knutsson, Hans, et al.
(författare)
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Vilda västern del 2 - Phoenix vill vara bäst i klassen
- 2003
-
Ingår i: Svenskt Vatten. - 1651-0674. ; :2003:3, s. 46-47
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Hur kan det komma sig att Staden Phoenix i Arizona har bland de lägsta va-avgifterna i hela USA? När vi i förra numret av Svensk Vatten gav en kort beskrivning av hur stadens vattenförsörjning utvecklats avslutande vi med denna fråga. Liksom i Sverige är verksamhetens historiska utveckling, platsen och dess fysiska förutsättningar viktiga delförklaringar till de låga kostnaderna. Det handlar emellertid också mycket om hur de långsiktigt och målmedvetet arbetat med verksamhetens organisation och styrning.
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| 24. |
- Knutsson, Hans, et al.
(författare)
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Är du stark nog att samverka?
- 2004
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Ingår i: Kommunal ekonomi. - 0282-0099. ; , s. 39-40
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Somliga kanske ser ”interkommunal samverkan” som ett desperat uttryck från svaga kommuner, kämpande för sitt liv. Så kan det vara i en del fall, men inte i alla. Det krävs nämligen kraft för att hjälpas åt. Att lämna över en del av sitt eget öde – och ta ansvar för andras – är ingen avkoppling. Att samverka kan med andra ord likaväl vara ett tecken på styrka och framgång som en signal om svaghet och tillbakagång. Efter att ha studerat ett antal fall av interkommunal samverkan de senaste åren anser vi oss berättigade att uttala oss utifrån olika exempel på samverkan. En lång rad renhållningsfall, Bergslagens Kommunal¬teknik – landets första kommunalförbund för teknisk driftsverksamhet och, ej att förglömma, erfarenheter som sträcker sig tillbaka till bildandet av Roslagsvatten och försöket med TENK. Vi ska här diskutera ett antal ”postulat” kring interkommunal samverkan och därigenom också sammanfatta ett antal generella samverkanskarakteristika som kan vara lämpliga att ha i åtanke när diskussionerna förs ute i våra svenska kommuner.
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| 25. |
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| 26. |
- Lundberg, Peter, et al.
(författare)
-
Detection of neural activity in functional MRI using canonical correlation analysis.
- 2001
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- A novel method for detecting neural activity in functional magnetic resonance imaging (fMRI) data is introduced. It is based on canonical correlation analysis (CCA), which is a multivariate extension of the univariate correlation analysis widely used in fMRI. To detect homogeneous regions of activity, the method combines a subspace modeling of the hemodynamic response and the use of spatial relationships. The spatial correlation that undoubtedly exists in fMR images is completely ignored when univariate methods such as as t-tests, F-tests, and ordinary correlation analysis are used. Such methods are for this reason very sensitive to noise, leading to difficulties in detecting activation and significant contributions of false activations. In addition, the proposed CCA method also makes it possible to detect activated brain regions based not only on thresholding a correlation coefficient, but also on physiological parameters such as temporal shape and delay of the hemodynamic response. Excellent performance on real fMRI data is demonstrated. Magn Reson Med 45:323-330, 2001
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| 27. |
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| 28. |
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| 29. |
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