Dear SPMers,
I found that the SPM significance for ERP dataset (SPM8) could hardly survive after correction for multiple comparison (e.g. p < 0.05, FWE or FDR correction). Now I often use p < 0.01 (or 0.05) without correction and the extent threshold k > 400 (or 200) for the whole scalp analysis from 50 ms to 950 ms after stimuli onset (SPM even shows the significant comparisons during baseline. These results are easy to confuse me, so I use a mask to exclude the very early comparisons). I found that the same component significant in SPM map could be detected by SPSS more significantly. However, I prefer to SPM8 for its convenience to show the significant results. Have you any ideas to do correction for multiple comparison in ERP data? Any suggestions are welcome.
Sun Delin
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