Another cool paper published earlier this month, with results that seem to align with the heterarchy aspect of TBT.
Summary: https://www.science.org/doi/10.1126/science.adt8343
Full paper: science.adt8343.pdf (7.0 MB)
Epilepsy patients with ventral temporal cortex electrodes were shown objects, then asked to imagine them. Researchers recorded the electrodes in both instances, and found significant similarity regarding which neurons are active during perception and during imagination of a particular object.
This shows that higher-level regions utilize feedback connections during visual imagination to reactivate the same lower-level columns where an object representation was originally memorized. There were decades-long speculations about this, but it was never actually observed empirically until now.
Interesting tidbits from the discussion:
The source of the top-down signal driving VTC reactivation during imagery remains an open question. Candidates for this source include the hippocampus and prefrontal cortex, given their involvement in various forms of memory (65–70), their dense connections to the VTC (71, 72), and the known ability of human hippocampal neurons to be selectively reactivated by free recall (13, 73). Another question is the relationship between the VTC signals during imagery and those previously reported in primary visual areas (V1 and V2) (23, 74). Given hierarchically organized feedback connections (71), we hypothesize that the VTC signals may be driving the imagery-related signals in earlier visual areas.