Dear Conn-Users

I have a short question. I am writing a batch script and I would like to use the first principal component of my ROI only.

In the conn_batch_help document it says:
dimensions : rois.dimensions{nroi} number of ROI dimensions - # temporal components to extract from ROI [1] (set to 1 to extract the average timeseries within ROI voxels; set to a number greater than 1 to extract additional PCA timeseries within ROI voxels; set to 0 to compute a weighted sum within ROI voxels (ROI mask values are interpreted as weights))
From the description it is unclear to me, to which number I need to set it to only get the first principal component? 

A short advice would be greatly appreciated!

Isabel