It gets interesting later:
To verify the response, the researchers conducted another study in which four researchers stood in the room. Participants were told that while they were blindfolded and operating the machine, some experimenters might approach them without actually touching them. The researchers told participants to estimate the number of people close to them at regular intervals. In reality, no researcher ever approached the participants. Yet people who experienced a delayed touch on their back felt more strongly that other people were close to them, counting up to four people when none existed.
Maybe I am blindfolded, but what's interesting about this? Test subjects were blindfolded in a room with people and were told those people would come close to them but not touch them. Then something poked them, which due to desyncronization they could not relate to their actions. So they concluded that someone was poking them. And being in an uncomfortable situation (blindfolded with people in the room, operating a machine of unknown purpose - or did they know it was a poking machine?), being doubtful if the researchers had spoken the truth about coming close but not touching (because this is what you think about in the situation), and figuring that there must be some purpose to this experiment (because this is what you do), some people guessed more people were actually in the room. Big whoop?