Given that we don't know what PEM is biologically, and whether cognitive exertion includes dealing with sensory stimuli and emotions
Well I appreciate that we dont know what PEM is biologically, but surely we know that it takes energy for the brain to process sensory input? It's all activity. Just as an aside i sometimes wish it were called PAM as it's often very low level activity rather than what we think of as exertion.
Do emotions on their own trigger PEM?
Not for me, or at least not that i can notice, because for me I always have to
do something in order to process strong negative emotions or they just eat me up & because the adrenaline/stress hormones give me the illusion of feeling much better than i actually am, it puts me at very high risk of overdoing it, so it's better to process or express my feelings as while the activity required to do so may cause PEM, it will be less bad than if i stay 'adrenalined-up' & overdo it badly as a result of missing the 'done enough' ques due to the adrenaline.
So for example I might lie here scribbling on blank paper with rage for example - so I
think emotions only cause PEM because I do some kind of activity as well as the feeling, because I dont find I'm aware of getting PEM after joy, because i dont feel the need to discharge it (which usually requires some kind of physical or at least extra mental activity).
But I am not
very-severe. I can easily imagine that perhaps even positive emotions alone are some kind of activity for the brain & body to process them, so from that POV could easily trigger it...
IF we take it that all activity above a certain threshold triggers PEM.
Given that simply too much reading (while lying completely flat) can trigger the same delayed 'now i have the flu including swollen glands/sore throat' type PEM, (ie that the energy expenditure of too much brain activity
alone can cause it), I dont understand why there is doubt over whether sensory activity can trigger it. I know it may
feel like sensory porocessing is an entirely passive thing - listening to sound etc, but lying still while it's happening doesnt make it physically passive, its
not passive.
In response to the question "does it take energy for the brain to process sensory input"? Google AI says this (I have bookmarked the page should the sources it used be helpful but i dont have the capacity to look at them right now)
Yes the brain uses energy to process sensory input, with the brain consuming a significant amount of the body's energy for its functions, including sensory processing.
Here's a more detailed explanation:
- Brain's Energy Demands:
The brain, despite being only 2% of the body's weight, consumes about 20% of its energy supply. This is because it's a highly active organ with countless chemical reactions occurring every second.
- Sensory Input and Energy:
Specialized sensory neurons respond to stimuli from the environment, and the brain interprets this input, generating neural impulses that allow us to respond. This entire process, from receiving sensory information to generating a response, requires energy.
It might help me clarify the situation if we get some descriptions of emotions or sensory challenges that have triggered PEM for you, or other responses to these that seem different from PEM, for example, lowering your PEM threshold, or immediate symptoms that don't lead into PEM.
Lying flat in a room flooded with sunlight (which i find inherently pleasant when very well rested - i love the sun (obviously if i'm not well rested its agony but thats a different story. I'm trying to think of examples I can give of sensory stimuli leading to PEM on their own. I need to think back because my life the last couple of yrs have not offered me the opportunity to use my 'well-rested-time' on such pleasant things.
So if I lie in a well rested state - my 'well rested' state means i can walk, slowly the 4mtrs to the bathroom use the loo & then walk back. I'd be tired after & feel more dizzy on the return journey but I'd manage it without a lot of issue, as long as i didnt have to do it more than once without a good rest inbetween)
So in the example I'll b lying down in a room flooded with sunlight (albeit with a sun visor on, but the colour of sunlight lifts my spirits so i liked to have it if possible), and listening to something i find pleasant - bird song through the window or my favourite relaxing music for example...
If i do that for too long it leads to an immediate symptom increase - feeling nauseated, very dizzy, confused, very weak "fatugued" physically, unable to walk to the bathroom without bumping into the wall, pain levels & all cognitive functions significantly worse, even to the point i cant understand what's being said to me. My coordination goes completely awry, etc etc all the usual stuff.
PLUS, the
previously enjoyable sound & light become excruciatingly painful, physical torture. Increasing ALL my symptoms, & I may even find i cannot move at all, effectively paralysed other than breathing & eye movement, until i have at least a while spent in silent darkness. There were occasions when i was more moderate, where it would happen in the garden, where if there was no one to help me & i went out there without ear defenders/eye mask, i wouldnt even be able to crawl back inside until the birds stopped singing!
This 'collapse' can be
somewhat aleviated by rest - 1-4hrs for example, where i wont go back to my well rested baseline, but will
improve.
I may or may not pay for it next day with 'proper' PEM - ie all of the above plus flu/infection-like symptoms. But if i do, the episode will be less severe & shorter lived than in the following scenario...
If I am well rested
but also a bit nervous of something that is happening next week or something has just irritated me, both of which triggered stress hormones that increase my tolerance for sensory stimuli
in the moment, that will cause me to listen for much too long - so I am conned by the adrenaline in how long i think i am able to manage it for....
then i will go not just to the point of collapse as i did before, but far beyond it, because I have not picked up on the 'stop now' signals & massively overdone it. I usually only stop because i just feel tired.
(just as an aside which explains the following example, I dont body-watch or use much time-contingent pacing, I use symptom contingent pacing, because I find it impossible to know how long i can do anything for, because it all depends on how much other stuff i done. I know people find it helpful but i just never got my head around it - i say that because it explains the next bit....)
So I am never aware of that huge adrenaline-induced sensory 'over-do', until the delayed PEM hits & I wonder what the heck is going on because i dont think I done anything to cause it.....
And then i think ''oh, wait, I listened to that
whole CD yesterday AND the sun was shining!!

... WOW! no wonder! man that was foolish"