I recall seeing a programme a few years ago where professional drivers were given varying amounts of whisky (hard life) and then asked to repeat tasks they'd previously done. On that occasion it included driving tasks in a safe environment off a public road.
It wouldn't be all that difficult to do something similar using a flight sim (and given the opportunity both to get drunk and aid flight safety you'd find no shortage of volunteers). The question is, has anybody done such an experiment - and can anybody point out where to find the results if they have.
G