Tying a finger to help memory recall

Question

I was playing Zynga's Draw Something when I saw an interesting icon:

A quick search of "tying fingers" produces results such as:

• Big Site of Amazing Facts

This is a carry-over from olden days when people tied pieces of cloth around any painful part of their body.

This cloth was tied in one area to keep the “spirit of life” in that area, and so cure it and keep the pain from spreading to other parts of the body. The string on the finger was designed to “keep” the thought there, to be remembered later when it was needed.

which looks immediately dubious. But there are also some "scientific" (or pseudo-scientific) claims like the accepted answer in the other QA website:

• Yahoo Answers

  It's a little known fact that the nerves that define your sense of touch on your index fingers are the ones with the quickest connections routed directly to the hippocampus, the part of the brain responsible for memory. Tying a ribbon around the index finger means you constantly have a texture that's activating those nerves and thus keeping that part of the brain in alpha (high activity) mode. If you tie the ribbon (or wear a ring on your index finger, or any such apparatus) at the very moment you are trying to memorize something you mustn't forget later on, it associates that brain activity with said memory, keeping that pathway almost exclusively as a conduit for that memory.

That tying a knot on your fingers improves remembering things seems like a reasonable claim to me as a memory technique, since it is something unusual which you normally don't do unless you have something you want to recall later; but is it more effective compared to other arbitrary memory technique, say, drawing an "X" in the palm, or tying the leg, putting a pen in the breast pocket, etc.

Answer 1

I doubt there is any such research, and I think explanations involving nerves routed directly to the hippocampus should be taken with a grain of salt at best. If you Google "index finger nerves hippocampus" you are directed to articles about carpal tunnel syndrome, which mention that nerves from the thumb, index, and middle fingers all feed the median nerve, which runs through the carpal tunnel. Does not sound like a direct connection.

The reason tying a string around your finger is canonical is, I am sure, an accident of cultural history. According to this page, the OED traces the idea of tying a knot in something as a memory aid back to around the year 1000. I recall as a child in the 1970s being told that you might tie a string around your finger so you won't forget something, but it didn't seem like people actually did it. The idea seems to have become less familiar over the decades since, and I'm not sure why.

I think your assessment of its effectiveness and method of action makes sense. That was how it was explained to me as a child, anyway.