Professor Sommer was elected as a member of the Young Academy of the KNAW (Royal Dutch Academy of Sciences) and is a member of the Permanent Committee for Large Research Infrastructure at NWO. She is consultant to GABATHER, a small company developing new GABAergic treatment for psychiatric disorderd and a member of the Dutch Committee for Research Integrity (LOWI). She is associate editor of Schizophrenia Bulleting, Psychological Medicine and the Dutch Medical Jorunal (NTVG).

She published two popular science books. The most recent, Haperende Hersenen, became a national best seller. Sommer published over 250 articles on hallucinations, language, cognition, and psychosis. Her current research interest is related to the association between cognitive dysfunction and activity of the immune system. Her aim is to develop new treatment to support people with cognition deficits during their recovery of medical, psychiatric of neurological disorders.