Because of the heterogeneity of brain function and its relationship to behavioral traits and characteristics in every individual, it would be difficult if not impossible to calculate or study and reach to a unanimous formulation of the brain energy consumption, unlike a combustion engine that has less variables in its input/output properties and has a linear model of function.

You already seem to have studied Raichle et al. as one of the main studies regarding brain energy consumption.

But I believe that our reflection and view toward the brain energy consumption should inoculate a sense of regional metabolism to overall metabolism. In many of our routine activities, many parts of the brain tend to be less active compared to the overall net energy consumption and metabolism of the brain even at rest.

Unless we use goal-directed approach and specific task to study the brain function, BOLD and HRF (which can be associated with metabolism too) changes via fMRI and fNIRS, we cannot substantiate any theoretical calculations regarding the brain energy consumption.

https://science.sciencemag.org/content/283/5401/496

I also recommend using FDG-PET scans to exclusively focus on glucose and energy consumption of different ROIs.

Article Magistretti PJ, Pellerin LCellular mechanisms of brain energ...

Tobias Debatin wrote a very interesting summary on the relation between energy consumption and intelligence.

" A Revised Mental Energy Hypothesis of the g Factor in Light of Recent Neuroscience "

Maybe that is relevant to your Question.

Dear Colleagues,

thank you very much for your interesting hints - I'll study them!

Hello

I hope this could help you

https://www.pnas.org/content/106/21/8719

https://www.sciencedirect.com/science/article/abs/pii/019188699390206I

Good Luck