User guide mentions that FIRST glm is different from FEAT ie it does not model separate group variances and ignores the "Group". Given this, do we have a way to perform ANOVA analyses? I am interested in performing 2-factors 2-levels ANOVA.

Since “group” is not allowed, I tried performing interaction analyses by entering the parameter as single EV while providing positive values for first group & negative values for second group [multplying by -1]. Please advise whether this is appropriate.

Is it mandatory to provide F-contrast? If yes, why so? I am interested in directional [one-tailed] changes and would like to specify only t-contrasts.

I am familiar with visualizing output images of 'randomise' tool in FSLview. However, this particular line from FIRST user guide confuses me - “Interpretting the results of a correlation: the values in the p-value images will give the probability of a zero correlation (the null hypothesis) at each vertex.” Does this mean that correlation result images will have 'p values' instead of the usual '1 - p values' ?