[pymvpa] searchlight for data with different runs with different masks

Yaroslav Halchenko debian at onerussian.com
Sun Dec 20 04:00:23 UTC 2015

On Sat, 19 Dec 2015, Kaustubh Patil wrote:

> Thanks a lot Yaroslav. I am following a procedure as described below please
> let  me know if it has any clear or potential problems. I am also throwing in
> another questions here but can start another thread if its worth.

> 1) Alignment procedure: Align all the runs to the middle volume of run1
> (example_func from fsl). Use the mask that was generated by fsl form run1.


> 2) MVPA: do the classifiers give balanced accuracy as my datasets are not
> balanced? 

might need rebalancing.  post output of your dataset.summary() here

> Also, is it recommended to run searchlight on betamap (after fitting
> hrf) or zscored raw data? 

whatever fits your bill.  usually betamaps, and possibly z-scored (per
run or across all)

> If betamap after fitting hrf then I using the
> provided function I get only one parameter per target per run, is that how its
> supposed to be?

ok if that is what you want to classify... some times you might
want model each trial separately.  there is no universal answer. 

Yaroslav O. Halchenko
Center for Open Neuroscience     http://centerforopenneuroscience.org
Dartmouth College, 419 Moore Hall, Hinman Box 6207, Hanover, NH 03755
Phone: +1 (603) 646-9834                       Fax: +1 (603) 646-1419
WWW:   http://www.linkedin.com/in/yarik        

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