Which brain circuits were most affected in this study - and what might that mean in everyday life?
The study shows something fundamental - reduced regulatory capacity of the brain. The problem is coordination, not character🧵
The study shows something fundamental - reduced regulatory capacity of the brain. The problem is coordination, not character🧵
https://twitter.com/zdenekvrozina/status/2023188802785693701
The most affected system was the salience network
(insula + anterior cingulate cortex).
Think of it as the brain’s regulatory switch.
It evaluates what is important, controls attention, and shifts the brain between rest and performance modes.
(insula + anterior cingulate cortex).
Think of it as the brain’s regulatory switch.
It evaluates what is important, controls attention, and shifts the brain between rest and performance modes.
When this network becomes dysregulated, the result is reduced capacity to regulate mental load.
Faster overload, lower tolerance to distraction, increased irritability under fatigue, and difficulty sensing internal limits.
Faster overload, lower tolerance to distraction, increased irritability under fatigue, and difficulty sensing internal limits.
In this study, this network showed the strongest disruption - especially after cognitive exertion.
This points to a core difficulty with switching and regulating effort under stress.
This points to a core difficulty with switching and regulating effort under stress.
The second key system was the central executive network (prefrontal cortex + parietal regions).
This is the brain’s management system - responsible for planning, working memory, and cognitive control.
This is the brain’s management system - responsible for planning, working memory, and cognitive control.
When its coordination weakens, everyday functioning may subtly change.
Tasks require more effort to organize, decisions become more tiring, multitasking becomes harder, and mental flexibility decreases.
Tasks require more effort to organize, decisions become more tiring, multitasking becomes harder, and mental flexibility decreases.
The study also found involvement of basal ganglia circuits.
These structures help initiate actions and maintain smooth cognitive flow.
When dysregulated, responses slow down and starting tasks becomes more difficult.
These structures help initiate actions and maintain smooth cognitive flow.
When dysregulated, responses slow down and starting tasks becomes more difficult.
Some regions showed increased connectivity - especially the angular gyrus.
The authors interpret this as compensation.
When regulatory circuits weaken, the brain recruits alternative pathways to maintain function.
The authors interpret this as compensation.
When regulatory circuits weaken, the brain recruits alternative pathways to maintain function.
But compensation is not recovery.
It often means higher energy costs, slower processing, and faster exhaustion.
In simple terms -
the brain works harder to achieve lower efficiency.
It often means higher energy costs, slower processing, and faster exhaustion.
In simple terms -
the brain works harder to achieve lower efficiency.
What may look like a change in personality is usually something else.
Lower cognitive reserve, reduced network coordination, and increased energetic cost of mental activity.
Lower cognitive reserve, reduced network coordination, and increased energetic cost of mental activity.
The salience network sits at a unique crossroads.
It connects cognition, autonomic regulation, body awareness, stress responses, and immune signaling.
This makes it especially sensitive to inflammation.
It connects cognition, autonomic regulation, body awareness, stress responses, and immune signaling.
This makes it especially sensitive to inflammation.
Neuroimmune connection?
Immune signals - including cytokines and microglial activation - can directly disrupt this network.
Even mild chronic inflammation can impair synchronization between brain systems.
Immune signals - including cytokines and microglial activation - can directly disrupt this network.
Even mild chronic inflammation can impair synchronization between brain systems.
Similar network patterns have been reported in
post-sepsis syndromes
Lyme disease
HIV-associated neurocognitive disorders
ME/CFS
post-sepsis syndromes
Lyme disease
HIV-associated neurocognitive disorders
ME/CFS
What is most concerning in this study is not just the presence of network disruption - but its dynamic nature.
The findings suggest an ongoing process rather than a static injury.
The findings suggest an ongoing process rather than a static injury.
Over time, key regulatory connections - especially those linked to prefrontal control - appear to weaken.
At the same time, compensatory pathways become stronger.
At the same time, compensatory pathways become stronger.
This pattern is consistent with progressive network remodeling.
The brain reorganizes itself to maintain function under chronic physiological stress.
The brain reorganizes itself to maintain function under chronic physiological stress.
It does suggest a continuing biological process - not merely a transient after-effect of infection.
The biggest unanswered question remains scale.
Long COVID likely exists on a spectrum, and we still do not know how many people experience similar network-level changes.
Long COVID likely exists on a spectrum, and we still do not know how many people experience similar network-level changes.
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