margulies
commented
8 years ago Many thanks for these helpful and constructive comments.
1) We have now defined 'medial wall' as follows:
– "from passing through nodes of non-cortical areas such as the non-cortical portions of the surface mesh described as the `medial wall'."
– "The second challenge, for which there was no prefabricated solution, was ensuring that the shortest path only traverses territory within the cortex proper, avoiding shortcuts through non-cortical areas included in the surface mesh --- most prominently, the non-cortical portions along the medial wall."
2) We have attempted to further clarify the zones analysis in the text and figure:
– "The distance measure provides a means to parcellate the cortex using the surface geometry. Towards that aim, we also implement a `zones analysis', which constructs a Voronoi diagram, establishing partitions based on the greater proximity to a set of label nodes."
In the figure, we have now included further presentation of schematic describing the two types of analysis. Please let us know if further clarification would be helpful for the reader.
3) We appreciate the need for further clarity on this point and have now added the following text in the "Approach" section:
– "Were the shortest paths between two nodes to traverse non-cortical regions, the distance between nodes would be artificially decreased, which would have artifactual impact on the interpretation of results. This concern would be especially relevent to the `zones analysis' described below, where the boundaries between regions would be altered."
Any further suggestions would be very much appreciated -- Daniel, on behalf of the authors
dnkennedy
This paper presents a nice description of a tool to measure geodesic distance along the cortical surface. It is demonstrated on Freesurfer output on subject data from the HCP data collection as a proof of concept. The results look promising and useful.
A couple of points of clarification may be helpful for the reader. 1) The term 'medial wall' is not particularly clear and could use definition. 2) In the description of Figure 1, the concept of ‘zones analysis’ introduced rather abruptly, and it seems Figure 1 is about both the central and calcimine sulci. Since 'zone analysis' seems to be an important par of the result, this should perhaps be introduced in a little more detail in the approach. 3) Since ‘exclusion of medial wall' as a confound is touted in the approach, is it possible to comment on the effect (magnitude, difference in inter-zone boundary, etc.) that this correction makes?