open-discussion > Sample characteristics and use of the IIT Human Brain Atlas (v.5.0)
Showing 1-2 of 2 posts
Results per page:
Jan 15, 2020  05:01 PM | Olivier Potvin
Sample characteristics and use of the IIT Human Brain Atlas (v.5.0)
Thanks for the great work. I have 2 questions before we use the IIT atlas:

1) I was wondering what were the characteristics of the subjects used for v5.0 of the atlas? Is it the sample of 72 healthy young and middle-aged adults (22 male, 31+-> 13 years of age, 18–59 years of age) from the Enhanced Nathan Kline Institute Rockland Sample referred to in the Zhang & Arfanakis (2018) Neuroimage paper ?

2) We are planning on using your connectivity matrix from the DK atlas (IIT_connectivity_matrix.txt). I was expecting higher connectivity between the same regions in the left and right hemispheres. Since I am not in the connectivity field, I was wondering whether it is ok to use this connectivity matrix as a measure of axonal strength between each DK region, even for the same region in both hemisphere.

Thank you.
Jan 16, 2020  06:01 AM | Konstantinos Arfanakis - Illinois Institute of Technology
RE: Sample characteristics and use of the IIT Human Brain Atlas (v.5.0)
Hi Olivier,

First, thank you!

Regarding your questions:

1) Not exactly. The diffusion tensor template of the IIT Human Brain Atlas was developed based on data from 72 healthy human subjects (28 male, 29 ± 6 years of age, 20 - 40 years of age) collected ON SITE using a 3T General Electric MRI scanner. For more details see Appendix 2 of the Zhang & Arfanakis (2018) Neuroimage paper. This link should do it, otherwise navigate to Appendix 2 through the actual paper, . These were NOT NKI data, but data we collected on site.

2) Although connectivity between homologous regions in the two hemispheres seems to be generally lower compared to that of regions within the same hemisphere, there are indeed several strong connections between homologous regions in the two hemispheres in our connectivity matrix. Also, we recently compared track-density maps and location of the strongest ~300 edges of the IIT atlas to those in single participants of the human connectome project (HCP), and saw that the edges of the IIT atlas are highly representative of those of HCP participants. Finally, the connectivity matrix provides the number of streamlines connecting two regions which can be thought of as an estimate of connection strength. But that is just a tractography-based estimate. If you could please provide more information about how you are planning to use the connectivity matrix "as a measure of axonal strength" I may be able to help you more.