I call this trick with the string "Hanging" merely because it is done around the neck. I saw it done by the Filipinos of the Linao Moro and Negrito tribes. Dr. Furness was shown it in the Caroline Islands by the girl "Dakofel."
String Figure Notation (SFN)
Put SN around neck
rH gr rS and tw ar neck
OA with hS: re LN: L pu fFS
ex H up over head, put head into FLN: re T: ex qu
The reason for the strings coming off the neck, after you have apparently wound them on securely, is because when you put the index loops over the head you reverse the direction of the strings already on the neck and they are no longer wound around on it.