Tickle research

[From Rick Marken (960415.1130)]

David Wolsk (960414 1045 PT) --

My reaction to the stimulus of an accusation of thinking in S-R terms was

Sorry. I didn't mean to accuse you of S-R thinking. I was just trying to
suggest what might be wrong with an S-R analysis of the situation (which I
didn't mean to imply was the analysis _you_ believe was correct) .

Tickling is actually an interesting phenomenon and one that's fun to
study. It's interesting because it seems very S- R; touching a person in a
tickling way certainly seems to _cause_ a laugh. It's fun to study especially
with someone you love (this ruled out Rush for me). So I did some tickle
research with my wife this weekend. I wasn't too systematic about it because
we were laughing our heads off. But I think I've made some progress.
My new model of tickling is as follows:

tickle -->CV-->| CS |-->muscle-------->laughter (side effect)
          ^ contraction
          > >

The CV (identified from my subjective experience) is that funny sensation you
get when someone touches you under your arm, say. The tickle is the touch;
this tickle touch increases the funny sensation; the funny sensation can be
reduced by muscle contraction.

The reference level for the funny sensation is typically zero at first
(after some tickling the reference seems to change; the person actually
seems to want more than zero of that funny sensation; I will say no more
about this for now because I am aware of the obsenity concerns on the net;-)
So when you apply a tickle there is error in the control system (CS) and
that error drives muscle contraction that offsets the effects of the tickle.
The compensating muscle contraction is quite abrupt and it seems to me that
it produces laughter as a side effect; that is, contraction of the muscles
involved in the tickle also seems to contract the diaphragm, abruptly forcing
air out of the lungs as a laugh (a laugh is a lot like a cough).

I think this is an interesting example because it shows how a side effect
(the laugh) of a control action (muscle contration) can appear to be an
effect that was directly caused by a disturbance (the tickle, which looks
like a stimulus). My tickle research also shows that the S-R appearance of
the relationship between tickle and laugh exists only when the disturbance
is introduced _abruptly_, requiring an abrupt countering contraction and the
resulting laugh. If the disturbance is gradual (you slowly bring the hand to
the skin and "tickle" _slowly_ and firmly) there is no abrupt muscle
contraction and no laugh. The importance of disturbance "abruptness" for the
illusion of S-R was pointed out by Powers in a paper called "A Bucket of
Beans" which, I believe, is reprinted in LCS II. The patellar reflex is a
particularly nice illustration of what is probably happening with tickling;
an abrupt disturbance (the hammar blow) to a controlled variable (tendon
tension) leads to a corrective response (muscle tensing) that produces, as a
side effect, a kick. The kick in the patellar response is analogous (I think)
to the laugh that results from a tickle.