The Mini-Cog test and the will be administered before surgery to all participants as cognitive assessment tool. The social-economical status will be evaluated regarding the level of education in years, level of physical activity, occupation, income and number of languages spoken (all categorized with appropriate scales). Also, during the preoperative evaluation, demographic data, alcohol consumption, smoking, use of visual or hearing aids, comorbidities, usual medication and preoperative laboratory test results will be obtained and recorded in a form. On the day of the surgery, as the patient arrives at the Operating Room (OR), the anesthesiologist will check for informed consent and the patient will be monitored with the following with the standard ASA protocol.