The tools exist today that can give estimates of blood flow in the brain. If there is a University or Medical College near you ask if they have any fMRI researchers -- these machines are millions of dollars each so go to the best places. There is also spatial EKG machines (if you have seen the skull cap with wires...that is one) that can measure this. This is not my area because that data I want to see is not measured in calories.

There is a literature, search brain caloric consumption, but I would be very suspect .. e.g., https://time.com/5400025/does-thinking-burn-calories/ is clearly pretty stupid from a neocortical burn rate perspective. The conclusions are about "alertness" which is kinda worthless.

An interesting contrast is that nearly all Computer CPUs and certainly all large Flast Storage Devices internally spatially regulate power. For example a 1GB flash drive is only fractionally powered up at any given moment...if all the circuits were powered simultaneously the chip would burn up.

Your 'near photographic' (eidetic) memory is real. You might find fMRI blood flow studies on that. It may well be that your brain blood flow regulation allows for more oxygen than other people. I would bet there is a literature on this. If not, whoever you talk to with an fMRI capability might well want to give you some scans. Find a cognitive neuroscientist. I know them here in Pittsburgh but not in Panama...but there might well be a few there. fMRI is Painless, fast, and much easier than the medical MRI scans. The machines look the same.

Another factoid for you. The average soldier in boot camp burns over 8-12,000 calories a day. I am pretty sure he/she is stressing his brains' neocortical power as much as any other part of his body.