Overview of the analysis process

The data analysis process usually proceeds in the following way. First the input images are assessed for correctness; any obvious processing errors are removed from any subsequent analyses. The question of what constitutes an outlier is often a tricky one. In order to avoid the temptation to manipulate the data in a biased way it is best if the person who reviews the input data is blind about the categorization of each particular dataset.

Once all the acceptable datasets are in place a series of descriptive statistics can be generated, usually consisting of means and standard deviations of all images in the study as well as of all the subgroupings. This is followed by generating statistical maps of the main variables of interest. These are then thresholded for significance while taking multiple comparisons into account. There is then often a series of steps in which new statistical models are analyzed and thresholded until the results become more understandable. This usually involves lots of plotting of individual datapoints.