Global-Task Correlations

calls rd_taskcorr2('Global')
Computes the correlations between the different task 
conditions and the global brain mean intensity.

Returns a table of the correlations and their corresponding
significance values. The correlations are computed over
the averaged timcourse during the peri-simulus period (or
Cond.min_elapse). Please see the Cond structure description
below for more information.

Cond    - structure containing information for each condition
.name   - name of condition
.iC     - corresponding column(s) in the design matrix xX.X
.iS     - corresponding condition indeces in each Sess
.iSC    - session specific indeces for this condition
.X      - task variates from xX.X collapsed across .iC columns
.g      - the average global brain during the peri-stimulus time
.G      - the average task variate during the peri-stimulus time
.rGg    - correlation (Pearson's R) between task and global mean
.t      - t statistic corresponding to .rGg
.p      - p value giving the significance of .rGg (two-tailed)
.onsec  - the onsets for this condition (in sec)
.onidx  - the onsets for this condition (in scans)
.num_scans  - (a guess about the) duration of the PST in scans
.min_elapse - the minimum time between consecutive presentation
              of trials or blocks of this condition type (it is
              used to make a guess about the duration of the PST)

Compatible with SPM99 files. 
Uses SPMcfg.mat to load parameters.

Condition names across different sessions are matched ignoring 
letter case. The order in which conditions have been entered in 
each session is not important.
---------------------------------------------------------------
@(#) rd_taskcorr.m 1.1      Kalina Christoff         2000-06-10 
@(#) rd_taskcorr2.m         Yuqing Gong              2005-01-05

