Brain Imaging & Analysis Center

• REFERENCE has many modifiers, which can be combined in a single -REF command or listed in separate -REF commands within a single command line. The “usage” line above shows only a few common modifiers. The complete list is:

-reference labels LABEL1 LABEL2 …
-reference codes CODE1 CODE2 …
-reference length LENG1 LENG2 …
-reference skip SKIPTIME
-reference delay DELAYTIME
-reference total TOTALTIME
-reference bin BINSIZE
-reference cycles
-reference events
-reference starts
-reference hrf Latency
-reference hrf Latency Transition
-reference hrf Latency Rise Width Fall [Undershoot Recovery]
-reference hrf Latency Dip Depth Rise Width Fall Undershoot Recovery
-reference name REFNAME
-reference expand [ref0] [Npts]
-reference convolve [ref0] ConvRef
-reference mask [ref0] MskRef -reference new

• SKIP -The ammount of time to ignore at the beginning of the time series
• DELAY -Indicates how much to shift each data point in time before applying the reference.

For blocks or cycles, only 1 full cycle needs to be specified; it will be expanded by repetition to fill the total time series being analyzed. (EXPAND can be specified to force expansion during creation.)

For some statistics (t-test, correl), reference time course may be convolved with a canonical response function (e.g. hemodynamic response) before being used. The RF can be specified globally using '-set convolve REFNAME', in which case the named REFNAME will be used automatically when appropriate. A convolution can also be specified explicitly using '-reference convolve' as part of the reference definition.

          E.g.:  -ref hrffunc.txt name MyHRFunc
                 -ref 10 10s convolve MyHRFunc name MyTask

T-test convolutions are only fixed delays

Note: Times for SKIP, DELAY, TOTAL, BIN, & LENGTH can be followed by 's' or 'i' (or 'S'/'I') to specify seconds or images (seconds is default).

See Also:
ILists, EventLists, ILists, Queries

fScan Home, fScan Manual, CmdLineOptions, Manual Help