The finding of this study have shown that people who had recovered from COVID-19, including those no longer reporting symptoms, exhibited significant cognitive deficits versus controls when controlling for age, gender, education level, income, racial-ethnic group, pre-existing medical disorders, tiredness, depression and anxiety. The deficits were of substantial effect size for people who had been hospitalized (N = 192), but also for non-hospitalized cases who had biological confirmation of COVID-19 infection (N = 326). Analyzing markers of premorbid intelligence did not support these differences being present prior to infection. Finer grained analysis of performance across sub-tests supported the hypothesis that COVID-19 has a multi-domain impact on human cognition.
https://www.thelancet.com/journals/eclinm/article/PIIS2589-5370(21)00324-2/fulltext
JAMA has shown that The most prominent deficits were in processing speed (18%, n = 133), executive functioning (16%, n = 118), phonemic fluency (15%, n = 111) and category fluency (20%, n = 148), memory encoding (24%, n = 178), and memory recall (23%, n = 170; Table 2). https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2785388
If these Cognitive Tests are still to be taken seriously then the baselines should at the very least be adjusted to the "New Normal" Which is implying if the baselines had any basis in reality in the first place.