Implicit Memory

Implicit memory formation and learning during general anaesthesia is a still debated question and no anesthetic regimen (ie intravenous anaesthesia vs inhalatory one) nor analgesic regimen (i.e. low or high opioids usage) has been identified for prevention. With this study the investigators aim to investigate if, during Total Intravenous Anaesthesia with Target Controlled Infusion (TIVA-TCI) different concentrations of Propofol at loss of responsiveness, maintenance and return of responsiveness can have a role in implicit memory formation.