This is not related to memory but i think, to some extend, it has some concern with mental power. It’s amazing. i really like this performance and wish that anyone here know how to do…
I don’t know how he does that, but you might like James Randi’s videos:
https://www.youtube.com/results?search_query=james+randi
Some people may hold on the forehead coin or spoon. But all this is the stickiness of the skin. 