¥ Basic unit of data in AFNI is the dataset
H A collection of 1 or more 3D arrays of
numbers
² Each entry in the array is in a
particular spatial location in a 3D grid (a voxel)
² Image datasets: each array holds a
collection of slices from the scanner
å Each number is the signal intensity for
that particular voxel
² 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
² There is one number in each voxel in
each sub-brick