Some kind of anaesthesia could be able to be used as theoretical models to build both hypothesis about awakening and methods for its study. There are codified anaesthesia for short operations, using few drugs with well known pharmacology. Studying awakening requires circumstantial screens to identify awake marks. Such a screen has been used for some years in this type of anaesthesia given for voluntary pregnancy termination. Similar but not identical marks are observed while the subject drop asleep and awake. They seem approximate marks observed with other screens used for coma awakening survey. But an interpretation of this marks, necessarily cautious, is usable only inside these anaesthetic conditions; if so, psychological explanations appears no more but no less useful than bio-pharmacological one.