Inclusion Criteria:  Elective cardiac surgery (coronary artery bypass surgery, aortic or mitral valve replacement/reconstruction, or combination surgery) with standardized extracorporeal circulation. A sufficiently good knowledge of German is necessary as neuropsychological tests are language-dependent.  Exclusion Criteria:  History of acute clinically relevant cognitive impairment of any cause (e.g., dementia, depression, stroke, multiple sclerosis) that may impair neuropsychological evaluation. Contraindications to the presentation of binaural beats or visual stimuli (e.g., epilepsy), Significant hearing loss or astigmatism, which may interfere with optimal perception of auditory and visual stimuli. Taking sedatives on the day of surgery. Unwilling to participate in the relaxation procedure or neuropsychological testing due to deteriorating health, lack of motivation, or other reasons. Participation in interventions that aim to change cognitive or emotional functioning which cannot be systematically controlled by our study team. Participation in an interventional study according to AMG/MPG will also be excluded. Patients with missing informed consent.