[Mne_analysis] spatio_temporal_clustering

[Mainak Jas]

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I want to add that the null hypothesis says nothing about the cluster
location. There is a nice paper that talks about this:

https://www.draschkow.com/app/download/9767211/16267843.pdf

You should exercise caution when interpreting the location of the clusters.

Mainak

On Mon, Apr 27, 2020 at 11:42 AM Eric Larson <larson.eric.d at gmail.com>
wrote:

>         External Email - Use Caution
>
> 1. as the p_threshold is decreased there should be the less number of
>> clusters. In our case its reverse. why?
>>
>
> Not necessarily. The initial p-value threshold (really the F_threshold you
> pass to the clustering function) just determines which points are included
> in clustering (at all). As this becomes more stringent, fewer points will
> be included. Finding more clusters with p < 0.05 as this threshold gets
> more stringent suggests that the data are somehow being denoised by being
> more stringent.
>
> FWIW TFCE is designed to make it so that you don't have to do this sort of
> determination, as it will automatically step through a number of
> thresholds, and the meaningful data (which for you seem to show up with
> quite stringent thresholds) should be enhanced automatically.
>
> 2. each time the clusters are localised at different regions.
>>
>
> Same as above, which clusters you find will be affected by which points
> you allow to be clustered in the first place. What you should find is that
> the clusters you get at more stringent thresholds are a subset of clusters
> you get at more relaxed thresholds. So for example if you have a cluster
> that contains five spatio-temporal points at a given threshold, if you make
> the threshold more stringent, this cluster should only shrink (or split) as
> the threshold becomes more significant.
>
> Eric
>
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