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Hello, We wish to run a regression analysis on some data we have. This is our first time attempting such an analysis, and we want to make sure we do it correctly. We performed a contrast at the individual level (1st level analysis) contrasting 2 conditions (condition - control). We are now interested in examining how activity in our experimental condition (compared to the control condition) is related to a measure of insight we have taken from each participants. So, we performed a second level analysis with multiple regression, imputing our contrast files (con_0001.img) for each participant, and adding their insight score as the covariate (one per participant). This creates a model with the insight scores, and a mean column. I am not sure why this mean column is necessary, as it is not present in more simple analysis using one-sample t-tests. Our question is, what is the contrast for our results? As we have only 1 regressor (insight), i am presuming it should be [1, 0]. However, we tried using [1 -1] and it gives a much wider pattern of activity, but a pattern that still make a lot of sense. While my feeling is that the correct contrast is [1 0], I wanted to confirm that this was the case. So, for our regression analysis, should we be using the contrast [1, 0] or [1, -1] in our results? Thanks a lot for the help! Colin.