| Title: |
Activelets: Wavelets for sparse representation of hemodynamic responses |
| Authors: |
Ildar Khalidov; Dimitri Van; De Ville; Jalal Fadili; Michael Unser; I. Introduction |
| Contributors: |
The Pennsylvania State University CiteSeerX Archives |
| Source: |
http://miplab.epfl.ch/exchange/activelets.pdf. |
| Publication Year: |
2011 |
| Collection: |
CiteSeerX |
| Subject Terms: |
Index Terms |
| Description: |
We propose a new framework to extract the activity-related component in the BOLD functional Magnetic Resonance Imaging (fMRI) signal. As opposed to traditional fMRI signal analysis tech-niques, we do not impose any prior knowledge of the event timing. Instead, our basic assumption is that the activation pattern is a sequence of short and sparsely-distributed stimuli, as is the case in slow event-related fMRI. We introduce new wavelet bases, termed “activelets”, which sparsify the activity-related BOLD signal. These wavelets mimic the behavior of the differential operator underlying the hemodynamic system. To recover the sparse representation, we deploy a sparse-solution search algorithm. The feasibility of the method is evaluated using both synthetic and experimental fMRI data. The importance of the activelet basis and the non-linear sparse recovery algorithm is demonstrated by comparison against classical B-spline wavelets and linear regularization, respectively. |
| Document Type: |
text |
| File Description: |
application/pdf |
| Language: |
English |
| Relation: |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.451.9524; http://miplab.epfl.ch/exchange/activelets.pdf |
| Availability: |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.451.9524; http://miplab.epfl.ch/exchange/activelets.pdf |
| Rights: |
Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
| Accession Number: |
edsbas.FCF231E4 |
| Database: |
BASE |