Connectivity
The Connectivity tab in the Overlay Toolbox contains a listing of loaded Connectivity (Dense, Dense Dynamic, Parcel, and Fiber Orientation) files and links.
URL links (loaded using Open Location... in File Menu) to remotely stored files are often used to access large (>30 GB) connectivity matrix files, loading one row of the matrix at a time as needed, rather than having to locally store and load the whole 90,000 x 90,000 matrix into memory.

- Load checkboxes toggle on/off data loading from the listed connectivity file for identified brainordinates (selected by left clicking on surfaces or volumes). If checked, every time a brainordinate is selected, data will be loaded into memory from that file for that brainordinate, regardless of whether it is displayed in any viewing tab. For best performance, toggle off connectivity loading for files not currently in use.

- Layer Data-series files support "dynamic connectivity". When a brainordinate is identified, the corresponding row to the brainordinate is correlated with all other rows in the file to produce a connectivity map displayed on the brainordinates. This dynamic connectivity produces the same data as found in a dense connectivity file without needing to create the dense connectivity file. Note that dense connectivity files may be very large (eg 9 GB).
- Copy copies the data from the currently loaded matrix row (for the currently selected brainordinate) and creates a new *.dscalar file containing this map data. The new file(s) created this way will appear and can be saved (and renamed, if desired) in the Save/Manage Files Dialog.

- Connectivity File lists links or paths to loaded dense or parcellated connectivity matrix files. For dMRI-based tractography connectivity (trajectory or *.traj*) files, an associated Fiber Orientation File must also be loaded for display and is listed to the right.