six feet wonder

A reader from Wheaton, IL offers two potential explanations for what makes the recent Double-Dare Physical Challenge challenging:

[...] There would seem 

to be two competing theories as to why the feat is impossible, or 

seemingly impossible.  A model of control basically looks like this:

   ---------------|

   |              |                       |---------------|

   |  Central     |   Control signals     |               |

   |  Cognitive   | --------------------> | Motor system  |

   |  Processor   |                       |               |

   |              |                       |---------------|

   |--------------|

Of course, it's a great over-simplification, but it will do to explain 

the competing theories.  The idea is that the central processor has to 

arrange a sequence of signals to the motor system so that the actions 

are carried out as desired (waving a hand to form a 6, or moving a foot 

around clockwise).  Often the control signals are considered a "fixed 

language" and learning occurs by having the central processor 

incrementally build chunks of signals to have useful scripts performed 

by the motor system.  Typically a lot of trial and error is involved in 

assembling these chunks of signals.  Most of this happens with little 

conscious awareness.

One theory (the hardwired/nativist theory) is that the language of the 

control signals is not rich enough to provide contrasting instructions 

to different segments of the body.  Again, to over-simplify for the sake 

of clarity, perhaps there is a directional bit that needs to be set 

whenever circular motion is needed.  A '1' indicates clockwise and a '0' 

indicates counter-clockwise.  If there is only one bit for both hand and 

foot, then it would be impossible to do the double-dare.

The alternate theory (learned behavior) is that it is difficult for the 

central cognitive processor to assemble the needed sequence of signals 

to issue the instructions for performing the double-dare.  One possible 

reason for the difficulty is that the central processor tends to use 

pre-fabricated chunks as much as possible.  In other words, it's usually 

most efficient to issue instructions composed of micro-routines that 

have already been developed and are well rehearsed.  (By the way, this 

is my best bet why it's really hard to get rid of an accent when 

learning a foreign language)  It might be the case that we are generally 

practiced to only give consistent sets of instructions.  Also, it might 

also be difficult to assemble these two scripts simultaneously because 

we are not very rehearsed with either one.

I'm going to practice the double-dare with a variety of techniques.  If 

I master it, that should lend some doubt to the first theory.

Okay, so I've just been trying this again. It seems that I can do this as long as I employ one of two strategies: one is to make big slow looping circles with my foot and then slowly trace the six; the other is to make really fast circles with my leg so that I've got some momentum going when I start to make the six. The biggest problem I have is trying to make an honest assessment of whether or not I am successfully doing it. What seems to happen when I am not successfully doing it is that my leg magically reverses direction, like the e-mail claimed, but that I stop making real circles with my leg and instead it is more or less just moving straight up and down instead of in a circle.

It's not at all apparent to me that I'm getting better at this with practice, although I've probably only practiced it for a dozen or so hours and tend to be a slow learner anyway. Such observations, it would seem to me, would support a variant of Theory #1: the task is asking the body to do something that it's wiring really doesn't want to do, but, the task allows for a sufficient range of ways it can be attempted that you can figure out 'work-arounds' that allow you to fulfill the letter of the task without, perhaps, fulfilling the spirit of the task in its prototypical sense.

This all seems in line with another e-mail I received about the task, from Boot Liquor, TX:

[name] tried to explain the physiological principle underlying 

this inability (first, she said "you can't make an 8 either, can you?"  

okay, it is not specific to the number 6).  I did not understand 

exactly, but seems to be that our brain must aggregate together the 

motions it thinks we will make simultaneously -- like the zillions of 

motions that are necessary to walk -- if we were to try to disaggregate 

them, we would overload the brains processing ability and, thus, be 

unable to walk.   Which would be worse of course, than not being able 

to spin our foot clockwise while tracing a 6 in the air.  I guess our 

brains did not anticipate that we would one day have so much free time 

on our hands that we would feel the need to do such an odd pairing of 

things simultaneously.