Abstract
Advances in Eelectroencephalography (EEG) and functional magnetic resonance imaging (fMRI) have opened up the possibility for real time data classification. A small amount of labelled training data is usually available, followed by a large stream of unlabelled data. Noise and possible concept drift pose a further challenge. A fixed pre-trained classifier may not always work. One solution is to update the classifier in real-time. Since true labels are not available, the classifier is updated using the predicted label, a method called naive labelling. We propose to use classifier ensembles in order to counteract the adverse effect of ‘run-away’ classifiers, associated with naive labelling. A new ensemble method for naive labelling is proposed. The label taken to update each member-classifier is the ensemble prediction. We use an fMRI dataset to demonstrate the advantage of the proposed method over the fixed classifier and the single classifier updated through naive labelling.
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References
Cozman, F.G., Cohen, I.: Unlabeled Data can Degrade Classification Performance of Generative Classifiers. In: Proceedings of the 15th International FLAIR Conference, pp. 327–331 (2002)
De Martino, F., Valente, G., Staeren, N., Ashburner, J., Goebel, R., Formisano, E.: Combining multivariate voxel selection and support vector machines for mapping and classification of fMRI spatial patterns. NeuroImage 43(1), 44–58 (2008)
de Charms, R.C.: Applications of real-time fMRI. Nature Reviews Neuroscience 9(9), 720–729 (2008)
de Charms, R.C., Maeda, F., Glover, G.H., Ludlow, D., Pauly, J.M., Soneji, D., Gabrieli, J.D.E., Mackey, S.C.: Control over brain activation and pain learned by using real-time functional MRI. Proc. Natl. Acad. Sci. USA 102(51), 18626–18631 (2005)
Eklund, A., Andersson, M., Ohlsson, H., Ynnerman, A., Knutsson, H.: A Brain Computer Interface for Communication Using Real-Time fMRI. In: International Conference on Pattern Recognition (2010)
Eklund, A., Ohlsson, H., Andersson, M., Rydell, J., Ynnerman, A., Knutsson, H.: Using Real-Time fMRI to Control a Dynamical System by Brain Activity Classification. In: Yang, G.-Z., Hawkes, D., Rueckert, D., Noble, A., Taylor, C. (eds.) MICCAI 2009. LNCS, vol. 5761, pp. 1000–1008. Springer, Heidelberg (2009)
Fleiss, J.L.: Statistical Methods for Rates and Proportions. John Wiley & Sons (1981)
van Gerven, M., Farquhar, J., Schaefer, R., Vlek, R., Geuze, J., Nijholt, A., Ramsay, N., Haselager, P., Vuurpijl, L., Gielen, S., Desain, P.: The Brain-Computer Interface Cycle. Journal of Neural Engineering 6 (2009)
Golub, T.R., Slonim, D.K., Tamayo, P., Huard, C., Gaasenbeek, M., Mesirov, J.P., Coller, H., Loh, M.L., Downing, J.R., Caligiuri, M.A., Bloomfield, C.D., Lander, E.S.: Molecular Classification of Cancer: Class Discovery and Class Prediction by Gene Expression Monitoring. Science 286(5439), 531–537 (1999)
Guyon, I., Hur, A.B., Gunn, S., Dror, G.: Result analysis of the NIPS 2003 feature selection challenge. In: Advances in Neural Information Processing Systems, vol. 17, pp. 545–552 (2004)
Handwerker, D.A., Ollinger, J.M., D’Esposito, M.: Variation of BOLD hemodynamic responses across subjects and brain regions and their effects on statistical analyses. Neuroimage 21(4), 1639–1651 (2004)
Hastie, T., Tibshirani, R., Friedman, J.: The Elements of Statistical Learning. Springer, Heidelberg (2001)
Haxby, J.V., Gobbini, M.I., Furey, M.L., Ishai, A., Schouten, J.L., Pietrini, P.: Distributed and overlapping representations of faces and objects in ventral temporal cortex. Science 293(5539), 2425–2430 (2001)
Ho, T.K.: The random space method for constructing decision forests. IEEE Transactions on Pattern Analysis and Machine Intelligence 20(8), 832–844 (1998)
Holmes, A.J., MacDonald, A., Carter, C.S., Barch, D.M., Stenger, V.A., Cohen, J.D.: Prefrontal functioning during context processing in schizophrenia and major depression: An event-related fMRI study. Schizophrenia Research 76, 199–206 (2005)
Hugdah, K., Rund, B.R., Lund, A., Asbjornsen, A., Egeland, J., Ersland, L., Landr, N.I., Roness, A., Stordal, K.I., Sundet, K., Thomsen, T.: Brain Activation Measured With fMRI During a Mental Arithmetic Task in Schizophrenia and Major Depression. American Journal of Psychiatry 161, 286–293 (2004)
Johnston, S.J., Boehm, S.G., Healy, D., Goebel, R., Linden, D.E.J.: Neurofeedback: A promising tool for the self-regulation of emotion networks. Neuroimage 29 (2009)
Kuncheva, L., Whitaker, C., Narasimhamurthy, A.: A case study on naïve labelling for the nearest mean and the linear discriminant classifiers. Pattern Recognition 41, 3010–3020 (2008)
Kuncheva, L.I.: Combining Pattern Classifiers: Methods and Algorithms. Wiley Interscience (2004)
Kuncheva, L.I., Plumpton, C.O.: Choosing parameters for random subspace ensembles for fMRI classification. In: Proc. Multiple Classifier Systems (2010)
Kuncheva, L.I., Plumpton, C.O.: Adaptive learning rate for online linear discriminant classifiers. In: Proc. S+SSPR, Orlando, Florida, USA, pp. 510–519 (2008)
Kuncheva, L.I., Rodríguez, J.J.: Classifier ensembles for fMRI data analysis: An experiment. Magnetic Resonance Imaging 28, 583–593 (2010)
Kuncheva, L.I., Rodríguez, J.J., Plumpton, C.O., Linden, D.E.J., Johnston, S.J.: Random subspace ensembles for fMRI classification. IEEE Transaction on Medical Imaging
LaConte, S.M.: Decoding fMRI brain states in real-time. NeuroImage (2010)
Lang, P., Bradley, M., Cuthbert, B.: International Affective Picture System (IAPS): Technical Manual and Affective Ratings
Li, M., Zhou, Z.-H.: Improve computer-aided diagnosis with machine learning techniques using undiagnosed samples. IEEE Transactions on Systems, Man and Cybernetics A 37(6), 1088–1098 (2007)
Misaki, M., Kim, Y., Bandettini, P.A., Kriegeskorte, N.: Comparison of multivariate classifiers and response normalizations for pattern-information fMRI. NeuroImage (2010), doi:10.1016/j.neuroimage.2010.05.051
Moench, T., Hollmann, M., Grzeschik, R., Muller, C., Luetzkendorf, R., Baecke, S., Luchtmann, M., Wagegg, D., Bernarding, J.: Real-time classification of activated brain areas for fMRI-based human-brain-interfaces. In: Medical Imaging 2008: Physiology, Function, and Structure from Medical Images, vol. 6916, pp. 69161R – 69161R-10 (2008)
Nigam, K.P.: Using Unlabeled Data to Improve Text Classification. PhD thesis, School of Computer Science, Carnegie Mellon University, Pittsburgh, US (2001)
Pereira, F., Mitchell, T., Botvinick, M.: Machine learning classifiers and fMRI: a tutorial overview. NeuroImage 45, S199–S209 (2009)
Plumpton, C.O., Kuncheva, L.I., Linden, D.E.J., Johnston, S.J.: On-line fMRI Data Classification Using Linear and Ensemble Classifiers. In: Proc. 20th International Conference on Pattern Recognition (2010)
Plumpton, C.O., Kuncheva, L.I., Oosterhof, N.N., Johnston, S.J.: Naive random subspace ensemble with linear classifiers for real-time classification of fMRI data. Pattern Recognition special edition on Brain Decoding (in Press, Corrected Proof, 2011)
Posse, S., Fitzgerald, D., Gao, K., Habel, U., Rosenberg, D., Moore, G.J., Schneider, F.: Real-time fMRI of temporolimbic regions detects amygdala activation during single-trial self-induced sadness. NeuroImage 18, 760–768 (2003)
Seeger, M.: Learning with labeled and unlabeled data. Technical report, University of Edinburgh (2001)
Sheline, Y.I., Barch, D.M., Donnelly, J.M., Ollinger, J.M., Snyder, A.Z., Mintun, M.A.: Increased Amygdala Response to Masked Emotional Faces in Depressed Subjects Resolves with Antidepressant Treatment: An fMRI Study. Biological Psychiatry 50(9), 651–658 (2001)
Weiskopf, N., Sitaram, R., Josephs, O., Veit, R., Scharnowski, F., Goebel, R., Birbaumer, N., Deichmann, R., Mathiak, K.: Real-time functional magnetic resonance imaging: methods and applications. Magnetic Resonance Imaging 25, 989–1003 (2007)
Yoo, S.S., Fairneny, T., Chen, N.K., Choo, S.E., Panych, L.P., Park, H.W., Lee, S.Y., Jolesz, F.A.: Brain–computer interface using fMRI: spatial navigation by thoughts. NeuroReport 15(10), 1591–1595 (2004)
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Plumpton, C.O. (2012). Online Semi-supervised Ensemble Updates for fMRI Data. In: Schwenker, F., Trentin, E. (eds) Partially Supervised Learning. PSL 2011. Lecture Notes in Computer Science(), vol 7081. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-28258-4_2
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DOI: https://doi.org/10.1007/978-3-642-28258-4_2
Publisher Name: Springer, Berlin, Heidelberg
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