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 ASA source analysis 
 
Source reconstruction in asa
ASA offers an extensive selection of neuroimaging methods for EEG and MEG analysis. Source modeling has advanced from single dipole solutions to LORETA, MUSIC and minimum norm estimates - and ASA supports all of these. Moreover, realistic head modeling using boundary elements can be applied irrespective of what particular source modeling approach is used. MRI based individually shaped head models can be interactively generated and provide more accurate solutions.
Full-screen display of an ASA analysis: The subject's MRI is shown together with the focus of EP activity as estimated with the MUSIC method. The map, EP traces and wavelets show different aspects of the data synchronized in time. 
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From signals to sources
ASA let's you apply source reconstruction methods within the regular workflow of your signal processing. All you need is good data!
You load an individual head model or the standard model that is installed with ASA, electrode positions, and MRI, then specify the time interval for analysis, and run the source analysis that suits your ideas around this particular brain activation.
LORETA is applied to the reconstruction of N1 in an AEP average. The display shows the result overlaid on MRI, the N100 map, the traces of the average, and a wavelet-based time/frequency plot (click to enlarge). 
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Integration of MRI
Individual MRI can be imported from DICOM files and is further processed for head and source modeling. The data are coregistered on the basis of anatomical landmarks. ASA provides interactive tools for the 3D image segmentation and head modeling, as well as a transformation from individual coordinates to standard Talairach coordinates.
The interactive MRI displays let's you add landmarks to coregister MRI with electrode coordinates and to transform individual MR images to the Talairach system. 
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Cortical imaging of distributed activity
The complexity of brain activity varties greatly, thus our mathematical modeling has to allow a sufficient degree of freedom to explain the measured data. ASA offers a representative set of methods for focal and distributed source modeling. Your results can be exported for further processing. The highly configurable 3D displays let you freely rotate and zoom into your results.
Somato-sensory evoked potentials were recorded using a 128 channel setup and reconstructed in ASA applying minimum norm linear estimates. 
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