The main objective of this project is:

1. To assess the impact of COVID-19 on the brain and executive functioning.

Twenty adult subjects of UZ Brussels (volunteers), who needed intensive care due to COVID-19 (n=10) or exhibited mild symptoms due to COVID-19 (n=10), will be recruited after hospital discharge. After signing an informed consent the subjects will undergo brain scans (T1, DTI, SWI, DWI, FLAIR MRI and rsfMRI), an emotion regulation task and a neurocognitive test battery. The latter test battery will be performed using an iPad and will test different neurocognitive functions such as memory, abstract thinking, spatial orientation and attention. The duration of the test battery is 18min. The total duration of one trial is estimated at one hour and a half. All tests are planned at the department of Radiology-Magnetic Resonance (UZ Brussel). After three months patients will visit the department of Radiology-Magnetic Resonance a second time for the same experimental trial. Additionally, a matched control group (n = 20; non covid or ICU patients) will be included and undergo the same tests in order to compare the results of the brain scans, emotional regulation task and neurocognitive test battery with results of both Covid-groups. Next to objective data, questionnaires will be filled out, i.e. visual analogue scales of mental and physical fatigue, Profile of Mood States and some additional return to work questions.

Inclusion Criteria:

• Adult patients of UZ Brussels, who left the hospital and needed intensive care
• Adult patients of UZ Brussels, who left the hospital and exhibited mild symptoms
• Healthy volunteers (who never had COVID-19)
• Ability to give informed consent
• Dutch or French speaking

Exclusion Criteria:

• History of neurological diseases

Both the "ICU COVID-19" and "Mild COVID-19" groups will be selected from COVID-19 patients that were admitted to the UZ Brussel hospital.

The "Healthy volunteers" group will be selected through the network of the involved researchers (convenience sampling).

Researchers, K De Pauw, R Meeusen, B Tassignon, J De Mey, L Van Liedekerke, H Raeymaekers, F De Ridder, G Nagels, J Van Schependom, M Vandekerckhove, L Van Imschoot, P Lacor, L Seyler, R Mertens, S Allard, AM Van Binst, LCB Fuentes, N Hoornaert, M Naeyaert, A Radwan, P Van Schuerbeek, S Sunaert and E De Waele will have access to IPD.

All electronic data is stored on the shared encrypted university drive. All files & written data will be stored in a locked filing cabinet. With only the previously mentioned researchers having access.

All data will be anonymized by assigning an exclusive identity code to each participant. The identity of the individual will only be known by the previously stated research team. Anonymized data will be stored for up to four years to allow for publication access, further analyses and auditing. All personal data, including health questionnaires and signed consent forms, will be destroyed within 12 months of study completion.