title          :: AFNI GUI: View model results (olay=coef, thr=stats)
presentation   :: 
scripts        ::
date           :: 2020-03
speaker        :: Taylor
outline        :: 
Brief look at header information of stats data
    + useful information like string labels associate with each sub-brick
    + degrees of freedom and other useful information saved
    + save both coefficient ('beta' or effect estimate) and associated (T-)stat
Overlay the Coef information
    + use AFNI-recommended 'scale' during processing to interpret Coef
    + Coef has interpretable units of local BOLD % signal change
    + we *strongly* recommend displaying the Coef values
    + make meaningful cbar ranges
      - probably ~3% for block or strong tasks
      - maybe ~1% for event or subtle tasks
    + is it bad to see large Coef outside brain (???)
      - no, because FMRI is veeery noisy
      - we use stat information to focus on high significance (low std err) voxels
      - we also often use group information to reduce noise effects
Threshold using the Tstat information
    + Tstat = (effect estimate) / (standard err)
    + with DF info, can convert Tstat to p-value (significance)
      - since we store DF info in AFNI header, can do this calc in GUI
    + so can threshold voxelwise stat as a p-value
Important to present ALL data from modeling
    + use threshold (of Tstat) to choose *where* to see stat info
    + use overlay (of Coef, not Tstat again!) to see effect estimate of model
Can see sub-threshold info still, usefully
    + thresholding helps to highlight strong results
    + but we don't want to lose info or hide artifacts, if we can help it
    + click the 'A' button above colorbar to see sub-threshold info
      - 'alpha' channel is turned ON (and can be toggled)
      - suprathreshold = opaque; subthreshold = increasingly transparent
    + click hte 'B' button above colorbar to put box around suprathreshold values
      - helps distinguish sub/suprathreshold values more clearly