The "index" toe right next to my big toe sort of feels like the middle finger does when I squeeze it... those two smaller toes after the index toe both seem like the ring finger, and the smallest matches the pinky finger as expected. I suppose if there is some kind of mapping from hands and feet all into the brain, there may some place where the toe sensory inputs are shifted over a little to make this phenomenon happen.
At first blush, the big toe might be mapped to the thumb, but seems most like the index finger in terms of the feel. Perhaps with a little bit of thumb mixed in.
So the mapping would be something like:
[Thumb] [Index] [Middle] [Ring] [Pinky]
[Big Toe] [Toe 2] [Toe 3] [Toe 4] [Little Toe]
Might be different for nonhuman primates...
