Clusters 2

Submitted by Ali on Sun, 08/28/2016 - 20:33

Dear Dr YAN

i hope you do will.

1-Video is very  fantastic ,but really i want reference for thioretical information of clusters.

2- if i have this cluster:

Cluster 1
Number of voxels: 60
Peak MNI coordinate: -36 -78 -45
Peak MNI coordinate region:  // Left Cerebellum // Cerebellum Posterior Lobe // Inferior Semi-Lunar Lobule // undefined // undefined // Cerebelum_Crus2_L (aal)
Peak intensity: 4.2667
# voxels structure
   60 --TOTAL # VOXELS--
   57 Left Cerebellum
   57 Cerebellum Posterior Lobe
   42 Cerebelum_Crus2_L (aal)
   24 Inferior Semi-Lunar Lobule
   18 Pyramis
   11 Tuber
    3 Uvula
    2 Cerebelum_Crus1_L (aal)
    1 Cerebellar Tonsil
my questions :
2.1-the nomber of these voxels (42Cerebelum_Crus2_L+2 Cerebelum_Crus1_L)  are  the activated voxels  and (60-44) not activated?
2.2-if the number of voxel is very small like 2 Cerebelum_Crus1_L (aal), is this region active region or not?
2.3- if the region repeated in two or more clusters what does mean that?
2.4- if I set cluster size with 13 voxels, can i take the 2 Cerebelum_Crus1_L (aal)  as activation region?
2.5-Based on what these regions included in this cluster?
2.6- Peak intensity: 4.2667: is this the peak value for the region that have maximum voxels in the cluster?
3- I have  P-value  after  FDR correctin =0.0037 , rmm=6 and 4mm gaussian smmoth , how many voxels in cluster size?
Are P- values in this image after FDR correction or before?
4- if I have this cluster:

Cluster 4

Number of voxels: 257

Peak MNI coordinate: -48   6 -33

Peak MNI coordinate region:  // Left Cerebrum // Temporal Lobe // Middle Temporal Gyrus // White Matter // undefined // Temporal_Mid_L (aal)

Peak intensity: 4.9106

# voxels               structure

  257       --TOTAL # VOXELS--

   88        Temporal_Inf_L (aal)

   60        Fusiform_L (aal)

   20        Temporal_Pole_Mid_L (aal)

   14        ParaHippocampal_L (aal)

    5          Temporal_Mid_L (aal)

4.1-if i set cluster size to 13 voxels which regions choose as active  and which of them noise regions?
4.2 -Can i take only the peak region from cluster or can i take more than one region in adition to the peak region?
thanks for your help.

Forums:

YAN Chao-Gan

Tue, 08/30/2016 - 01:36

2.1. Those are just labels, that means some number of voxels are labeled to some area name. They are NOT exclusive. All 60 voxels are significant.

2.2. The 2 voxels are significant at the cluster level. However, that doesn't mean you have enough confidence to interpret it as Cerebelum_Crus1_L is significant.

2.3. The are not exclusive, one voxel can be labeled to multiple are names.

2.4. See 2.2.

2.5. xjview.

2.6. Yes.

3. I didn't get the point. FDR only gives you a threshold of p value.

4.1. I guess you can interpret it as inferior temporal cortex and fusiform cortex.

4.2. As many as you think reasonable.