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Hi List, A question from a young SPMer. We have results in SPM2 from an event- related working memory paradigm, and we want to analyze data using reaction time as a regressor in order to isolate performance based effects. In other words, the goal is to identify the specific components within the neural network that vary depending upon task performance. To do so, we have been inputting the reaction times as a regressor at TRs of interest, and a 0 for any TRs of no interest. We then have two questions: 1) Will processing the data in this manner isolate those areas within the neural network that respond to change in RT? 2) When considering traditional ER designs, it appears that the vectors of interest for the data are time shifted to accommodate the delayed onset of the HRF, but that this is not the case for vectors of onset where other numbers (such as reaction times) have been entered. Does this delay need to be entered manually when conducting regression analysis? That is, should we shift our reference function by 2-3 TRs in order to accommodate the latency in the HRF or is SPM still doing this automatically? Thanks so much for your help. Sincerely, Neal Fitzpatrick