Chunk #29 — Connectivity methods — Proposed analysis algorithms to investigate directional connectivity in layer-dependent connectivity data — Feed-forward vs. feedback classification (in relation to Figs. 5 and 6).
Here, two templates of feedback vs. feed-forward driven layer-profiles were predetermined (blue and red in Fig. 6). In the feed-forward driven case, the template profile has one peak close to the center of GM. In the feedback driven case, the template profile has two peaks. One peak is located in the superficial layers and a secondary peak is located in the middle and deeper layers. Any columnar unit can then be classified as being feed-forward or feedback driven depending on whether the correlation of the profile is higher for either one of the template profiles. Each column’s feedback or feed-forward dominance can be represented by color maps that code for the relative correlation strength to either of the two template profiles. Here, each column’s layer profile was estimated in two ways:
