Amplitude Averaging
The last step in the data analysis process is to make a matrix of the average amplitudes. For each cell, the amplitudes for a time range and a set of channels are averaged. This matrix is exported from Matlab in a .txt format that can be imported into SPSS.
See an automation7 script for more info.
Example from the AA Dataset: For the N170 time window, a set of channels was averaged over the 150 to 200 ms time range.
N170 & EPN Channel Set:
{’94’, ’95’, ’96’, ‘105’, ‘106’, ‘107’, ‘115’, ‘116’, ‘117’, ‘124’, ‘125’, ‘138’, ‘150’, ‘151’, ‘159’, ‘160’, ‘161’, ‘162’, ‘169’, ‘170’, ‘171’, ‘178’, ‘179’}
LPP Channel Set:
{’85’, ’86’, ’95’, ‘122’, ‘104’, ‘120’, ‘112’, ‘121’, ‘132’, ‘133’, ‘143’, ‘103 94′, ’93’, ’84’, ’83’, ’82’, ’92’, ’91’, ‘102’, ‘101’, ‘111’, ‘118’, ‘119’, ‘131’, ‘130’, ‘141’, ‘142’, ‘152’, ‘110’, ‘151’}
Wavelet Analysis
Read the section on wavelets in the ERP Technique book.
Also, these articles are a helpful introduction to wavelets. They can be found on Mendeley in our EEG Analysis Group.
Wavelet analysis of neuroelectric waveforms: a conceptual tutorial. V J Samar, a Bopardikar, R Rao, K Swartz in Brain and language (1999)
