This is a nice baby step along the path to converting the study of brains from phenomenological to physiological. One of the important bits for me is the sheer breadth of inputs, this supports the construct of brain function having independent functional units which are accumulated into ventral and dorsal streams. Another bit of intriguing information is that they pretty solidly confirmed brain stem structures as not just having engrams independent of cortical/limbic inputs, but that these brain stem structures for this particular type of behavior was the most intensely activated. Another interesting bit was the confirmation that recall costs are fairly significantly lower, a possible explanation for the bias in reusing existing associations vs. creating new ones.
Altogether I think this work is strongly confirmatory of the salience/valence model, with the heavy activation and re-activation of brain stem structures indicating the initial “processing” or salience determination before passing it up to the valence processing centers.
I’m not a huge fan of the study setup as it only measures a specific type of stimuli in very specific conditions which makes it hard to know whether the results are consistent across all engramatic storage/recall function. It also smells like they got the data they were looking for with the amygdala/hypothalamus responses. Because of the lack of differentiation in behavior, it appears their data only captured “collection” rather than the engrams themselves. They also strongly biased their data to dorsal stream inputs due to the study setup.
Overall, pretty interesting.