Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Determining Patterns in Neural Activity for Reaching Movements Using Nonnegative Matrix Factorization | EURASIP Journal on Applied Signal Processing 2005 19 3113-3121 2005 Hindawi Publishing Corporation Determining Patterns in Neural Activity for Reaching Movements Using Nonnegative Matrix Factorization Sung-Phil Kim Department of Electrical and Computer Engineering University of Florida Gainesville FL 32611 USA Email phil@ Yadunandana N. Rao Motorola Inc. FL USA Em ail yadu@ Deniz Erdogmus Department of Computer Science and Biomedical Engineering Oregon Health Science University Beaverton OR 97006 USA Email derdogmus@ Justin C. Sanchez Department of Pediatrics Division of Neurology University of Florida Gainesville FL 32611 USA Email justin@ Miguel A. L. Nicolelis Department of Neurobiology Center for Neuroengineering Duke University Durham NC 27710 USA Emails derdogmus@ nicoleli@ Jose C. Principe Department of Electrical and Computer Engineering University of Florida Gainesville FL 32611 USA Email principe@ Received 31 January 2004 Revised 23 March 2005 We propose the use of nonnegative matrix factorization NMF as a model-independent methodology to analyze neural activity. We demonstrate that using this technique it is possible to identity local spatiotemporal patterns of neural activity in the form of sparse basis vectors. In addition the sparseness of these bases can help infer correlations between cortical firing patterns and behavior. We demonstrate the utility ofthis approach using neural recordings collected in a brain-machine interface BMI setting. The results indicate that using the NMF analysis it is possible to improve the performance of BMI models through appropriate pruning of inputs. Keywords and phrases brain-machine interfaces nonnegative matrix factorization spatiotemporal patterns neural firing activity. 1. INTRODUCTION Brain-machine interfaces BMIs are an emerging field that aims at directly transferring the subject s intent of movement to an external machine. Our goal .
