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 ASA signal analysis 
 
Signal analysis in ASA
ASA provides a complete set of functions to study continuous and event-related activity recorded with EEG/MEG. It facilitates a sophisticated data review, signal filtering and artefact handling, event detection, conditioning of triggers and subject responses, averaging in time and frequency domain, a variety of transformation tools, and of course averaging over groups of subjects. Analysis of large data sets is made efficient through the ASA Experiment Manager, which is an MS-Excel based application that tightly integrates ASA with automated processing of group data and post-processing of results.
 
 
Reviewing data
ASA gives you a maximum of flexibility for data review. The display can be configured for a particular purpose, e.g. an EEG/MEG combination with individual scales for channel groups. You can define customized montages with properties such as color, sensitivity and filters set for each channel or channel group. Easy navigation through your list of annotations, triggers, spike events etc, is supported; EEG and 3D mapping can be combined.
EEG and MEG are displayed simultaneously as overlaid channels per anatomical group. 
 
The signal processing chain
ASA allows you to call signal processing methods, such as conditioning, filtering, artefact detection, artifact correction, detrending, averaging and baseline correction in a sequence that automatically updates itself as soon as parameters are altered. Furthermore it offers features for re-referencing, re-sampling data or interpolation of lost channels. Also event-related de-synchronization and synchronization (ERD/ERS), group averaging - please contact us if you have specific questions concerning a particular method.
An EEG average in two conditions is displayed in a 2D layout. 
 
Export of data
EEG and averaged ERP traces can be exported as raw (ASCII) data or automatically into Matlab (EEGLAB). ERP images or 3D voltage maps can be easily copy-pasted into word-processing or presentation software. Peak latencies and amplitudes values of all traces can be exported into Excel using an integrated peak detection macro script.
 
 
FFT analysis
The ASA ERP license contains an FFT average feature that allows the calculation of spectral activity either over a self defined time-window or over events. FFT results can be displayed both in a 2D spectrum view and a 3D frequency map. Apart from standard frequency bands like theta, delta, alpha and beta, the user can create self-defined frequency bands. The spectrum results can be exported in ASCII format for the complete spectrum or for specific frequency bands.
FFT spectrum view