I just need to make sure my method is correct. I'm comparing two groups of people using SPM8 and MRI scans. We are looking for differences in gray matter based on their number of awakenings per night (that's the simplized version), which has been normalized using natural log, and we are controlling for age, BMI, and total cranial volume. Would a linear regression work in this situation? We followed the standard SPM8 instructions, using .005 significance with 80 voxel blobs. Thanks for any help or further directions that you can point me in.