Abstract
Synthetic aperture magnetometry (SAM) is a nonlinear beamformer technique for producing 3D images of cortical activity from magnetoencephalography data. We have previously shown how SAM images can be spatially normalised and averaged to form a group image. In this paper we show how nonparametric permutation methods can be used to make robust statistical inference about group SAM data. Data from a biological motion direction discrimination experiment were analysed using both a nonparametric analysis toolbox (SnPM) and a conventional parametric approach utilising Gaussian field theory. In data from a group of six subjects, we were able to show robust group activation at the P < 0.05 (corrected) level using the nonparametric methods, while no significant clusters were found using the conventional parametric approach. Activation was found using SnPM in several regions of right occipital-temporal cortex, including the superior temporal sulcus, V5/MT, the fusiform gyrus, and the lateral occipital complex.
Original language | English |
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Pages (from-to) | 1589-601 |
Number of pages | 13 |
Journal | NEUROIMAGE |
Volume | 19 |
Issue number | 4 |
Publication status | Published - Aug 2003 |
Externally published | Yes |
Keywords
- Adult
- Cerebral Cortex/physiology
- Cortical Synchronization
- Female
- Fourier Analysis
- Humans
- Image Processing, Computer-Assisted
- Imaging, Three-Dimensional
- Magnetics
- Magnetoencephalography
- Male
- Mathematical Computing
- Motion Perception/physiology
- Nerve Net/physiology
- Normal Distribution
- Occipital Lobe/physiology
- Orientation/physiology
- Pattern Recognition, Visual/physiology
- Psychomotor Performance/physiology
- Software
- Statistics, Nonparametric
- Temporal Lobe/physiology