May 22, 2022 Study released from Cambridge University states that:
"There is growing evidence that COVID-19 can cause lasting cognitive and mental health problems, with recovered patients reporting symptoms including fatigue, ‘brain fog’, problems recalling words, sleep disturbances, anxiety and even post-traumatic stress disorder (PTSD) months after infection. In the UK, a study found that around one in seven individuals surveyed reported having symptoms that included cognitive difficulties 12 weeks after a positive COVID-19 test.
While even mild cases can lead to persistent cognitive symptoms, between a third and three-quarters of hospitalised patients report still suffering cognitive symptoms three to six months later." https://www.cam.ac.uk/research/news/cognitive-impairment-from-severe-covid-19-equivalent-to-20-years-of-ageing-study-finds
The Study also states that the Cognitive recovery is slow and reading between the lines, states that since the entire population of the planet has been infected with COVID, overall cognitive ability of the entire population has dropped as well, thus any cognitive test baselines are now null and void. It's reasonable to assume that using pre-pandemic baselines has caused the failure rate of the Cogscreen to increase from its already high level.
The study does not factor in the acute effects caused by the mask mandates which compound the lowering of the cognitive ability of the mask wearer on top of the adverse effects caused by a COVID infection itself.