¥ Basic unit of data in AFNI is the dataset
H A collection of 1 or more 3D arrays of
numbers
o Each entry in the array is in a particular spatial location
in a 3D grid (a voxel = 3D pixel)
o Image datasets: each array holds a collection of slices from
the scanner
å Each number is the signal intensity for
that particular voxel
o Derived datasets: each number is computed from other
dataset(s)
å e.g., each voxel value is a t-statistic
reporting ÒactivationÓ significance from an FMRI time series dataset, for that
voxel
H Each 3D array in a dataset is called a sub-brick
o There is one number in each voxel in each sub-brick