Effect

The mentalist asks a mobile phone to a spectator, announces that it is going to make a search on internet and once is done, leave the phone on the table
asks the spectator if he had to find a medical dicease on internet, that would look for? The spectator names such as heart attack...

Under these conditions, the mentalist ask the spectator to take his mobile phone and look which was the search done
Under such conditions, the spectator will find a search on a medical portal with the exactly dicease named.