Everything goes blank, seizes up and nothing works properly. There is a general go-slow and your memory starts to fail. What you want to do doesn't happen and you start to heat up.
It gets scary when both you and the computer decide to do exactly the same thing at exactly the same time and you wonder in your heated state if computer viruses can jump the species gap a bit like H5N1 (avaian bird flu) and its at that point you realise you shouldn't be trying to interview people on the telephone let alone co-ordinating a conference call especially if you are thinking along the plot lines of Steven Speilberg's AI rather than concentrating on the ramifications of Empty Rates for Commercial Property on today's annuity rates for pensioners. ( my job as a journalist is a glamorous one - oh yes!)
It's amazing the things I think of when I should be concentrating and it is surprising how often I seem to get away with it, I mean people don't notice. It's a bit like driving really, you know the times when suddenly you are there and yet you don't recollect that you have crossed a major junction, driven through a village and negotiated a pair of extrermely nasty set of bends.
Perhaps the people I interviewed today did notice but were too polite to say: "Oi! Are you there Moriarty?"
See off on a tangent now thinking of Sherlock Holmes.