Very strong evidence in Post-Hoc but no main effect
I conducted a three-way repeated measures ANOVA (2x2x4) and did not observe a main effect for one of the factors, which is named "region of interest" (ROI). However, upon running a post-hoc test, I discovered strong evidence indicating a significant difference between the two levels of this factor (BF10 > 100). Any insights or ideas as to why this might be the case would be greatly appreciated.
Thank you for your input.