Because they compared them to the brains of healthy people, which while they have variation, have enough similarity to establish a baseline and recognize abnormality.
Not everyone has had COVID and there are antibody markers that only show up with exposure to the virus itself. I think the estimate is around 20% of the population was never infected.
But we also just have brain scans from before the pandemic.
Because they compared them to the brains of healthy people, which while they have variation, have enough similarity to establish a baseline and recognize abnormality.
but like everyone had covid. so you compare people with dysfunction with people feeling healthy but both had covid.
I’ve never had covid.
Not everyone has had COVID and there are antibody markers that only show up with exposure to the virus itself. I think the estimate is around 20% of the population was never infected.
But we also just have brain scans from before the pandemic.
I’ve never had Covid
Not everyone.