A post that never made it to CSGnet

[From Dag Forssell (991217 2330)]

When looking for Frans Plooij's address today, I came across a post that
belongs in the CSG record. A few months after the 1998 conference north of
Berlin, where Frans Plooij discussed the development of the HPCT hierarchy
in infants, the event level came up for discussion. Since Frans was not on
CSGnet, I sent him the discussion. I'll reproduce it below to provide
context for Frans reply.



I just downloaded a few posts from CSGnet. You may find them of interest.
Did you get the videos? Were they of any interest?

Best, Dag

Date: Wed, 28 Oct 1998 08:23:43 -0700
From: Bill Powers <powers_w@FRONTIER.NET>
Subject: Insights into level 5 (?)

[From Bill Powers (981028.0631 MDT)]

I've never been happy with the 5th level, "events." This morning my request
for a better definition was granted, sort of.

It started when Bill Williams was here (last week) and I showed him a video
of Bruce Abbott's rats "pressing a bar." This was the 25th day of
experimentation on a Fixed Ratio 1 schedule, so the rats were settling down
to a routine. The rats began each session hanging onto the bar and (just to
the right of it) the food cup, with their noses swinging toward the bar and
then toward the food cup as they leaned on the bar and (most of the time)
it went down and caused a pellet delivery. That image stuck in my mind, and
this morning I awoke with the results.

In conventional analyses, the pressing of the bar is conceptually separated
from the delivery of a food pellet, and that is conceptually separated from
consumption of the food pellet. This is how the human observer-experimenter
chooses to perceive what is going on. Thus the theory: the probability of
pressing the bar is increased when it results in delivery of a food pellet;
after the delivery there is a "post-reinforcement pause" during which the
pellet is consumed. As I watched the rats perform, this perceptual set
gradually faded and I began to see what was happening without this

The pause begins, during each experimental session, as a very brief
cramming of the pellet into the mouth in parallel with pressing the bar for
the next pellet, and half an hour to 45 minutes later, becomes a press, a
pellet delivery, and a fairly elaborate and leisurely ritual of sitting
back, holding the pellet in the paws, and turning it while nibbling on it
and chewing each bit thoroughly.
When we analyze the data in terms of presses per minute and pellets per
minute, what we appear to see is a declining pressing rate and pellet
delivery rate during each experimental session, with each press preceding a
pellet delivery. But if we forget those rates, we can also see this as a
declining rate of executing a cyclical process consisting of postures and
movements. Each time around, the cycle yields one consumed pellet, one
press, (or n presses on other schedules) and one new pellet (sometimes more
than one, but not often). At first, the rat goes through this cycle very
rapidly, skipping many details because of starting the next element before
the previous one is finished. The main thing limiting the speed of the
cycle is that the rat must swallow some of the food in its mouth before it
can get another pellet in. The rat often presses the bar and produces
another food pellet, then pauses while it chews before picking up the
pellet in the cup.

As the total amount of food consumed during the experimental session
increases, the speed of the production-consumption cycle decreases, and
each element, particularly the consumption process, expands to include all
its details. Eventually, as the total intake approaches a limit, the speed
of repetition approaches zero and other behaviors begin to appear such as
nosing around in the cage or taking a nap. The fast-slow pattern may repeat
once or twice, more briefly, before the end of the hour.

During this _repetitive cycle_ we see a number of controlled processes
going on. The posture transitions from the pressing posture, with the nose
toward the bar and one forepaw on it, to the collection posture, with the
nose toward the cup and a tendency to transfer weight to the cup-side paw,
which releases the press by the other forepaw. Early in the session,
loading the pellet into the mouth is followed immediately by a transition
back to the pressing configuration, so there is essentially no manipulation
of the food before it's stuffed into the mouth. The food is actually being
consumed at the same time that the next press is occurring. Later in the
session, the pellet is retrieved in the paws and nibbled on with the body
in a sitting posture, neither paw on the bar or food cup.

What is it that is being controlled here? The new idea is that it is a
_repetitive cycle_, with the _speed of repetition_ being the controlled
variable. Possibly we should consider each element of the cycle as being a
controlled _event_ as before, so we are now about to insert another level
of control above the event level, a new level at which the speed of a
cyclical event is the type of variable. Or perhaps we're replacing the
event level.

During the World Series, I heard the crowd clapping this way at a fairly
brisk pace, with each element taking the same amount of time:

clap (pause) clap (pause) clap clap clap (pause)
clap (pause) clap (pause) (pause) clap clap (pause)

That pause at the end isn't obvious unless this whole cycle is repeated.

What sort of controlled perception is this? It's basically a temporal
pattern (Bob Clark wanted to introduce a level of this kind many years ago,
but I couldn't connect with it. Now it seems he could have been right).

But it's not just a temporal sequence or a pattern of variation. It's
rhythmical. If you watch the rats go through their repetitive cycle, it's
easy to miss the steady rhythm that slowly decreases. Once in a while
there's what seems to be a reorganization -- a momentary break in the
rhythm, which stands out precisely because the rhythm is so regular the
rest of the time. Is this just a matter of each element having a controlled
duration? I don't know. But there is plenty of evidence that organisms,
particularly human beings, do all kinds of rhythical things.

The boy stood on the bur ning deck
^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^

These rhythmical things are patterns on a steady underlying rate of
repetition. They can be seen as related harmonic rhythms: if the pattern of
emphasis is written out, we have

       * * * *
The boy stood on the bur ning deck
^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^

Which is a pattern at half the speed of the underlying beat of the words.
If we take the initial "the" to be the last beat of a measure, we have the
musical notation with a beat at the start of each measure:

      > > > >
      >* |* |* |*
The |boy stood|on the |bur ning |deck
^ |^ ^ ^ |^ ^ ^ |^ ^ ^ |^
      > > > >

The slowest rhythm is the rate at which the whole cycle is repeated:

(1) | | | |
      >* |* |* |*
   ^ |^ ^ ^ |^ ^ ^ |^ ^ ^ |^ ^
      > > > >

(2) | | | |
      >* |* |* |*
   ^ |^ ^ ^ |^ ^ ^ |^ ^ ^ |^ ^
      > > > >

(3) | | | |
      >* |* |* |*
   ^ |^ ^ ^ |^ ^ ^ |^ ^ ^ |^ ^
      > > > >


Note that we can leave the words out, so that different lower-level
variables can be substituted: drum beats, flashes of light, bass drum
versus cymbal (^ = bass, * = cymbal, or vice versa), or musical pitch
(OOM-pah-pah OOM-pah-pah on a tuba).

Certain repetitive cycles and subycles are so strongly associated with a
specific physical process that we can recognize them easily:

ga-da-da-dump ga-da-da-dump ga-da-da-dump ...

There's probably a physical reason why there are two beats between
ga-da-da-dumps as the horse flies through the air. Three beats would leave
you on the wrong foot, four beats would mean jumping too far, and one beat
wouldn't give enough time to reset the first leg. So a four-legged creature
gallops in waltz time, or 6/8 time. Is that true?

Repetitive cycles. We need to control them to sing or play music, recite
poetry (doggerel, anyway), walk or run, push someone on a swing, pound
nails, saw wood, jack up a car, paint a wall, or write a list like this.
Many of them are tied to natural physical rhythms like gaits, but many are
not -- they're rhythmical because at this level speed of repetition is the
main controlled variable.

So, does this level go between events and relationships, or does it replace
events? Try it on, let me know what you think.


Bill P.

Date: Wed, 28 Oct 1998 16:24:58 +0000
From: Richard Kennaway <jrk@SYS.UEA.AC.UK>
Subject: Re: Insights into level 5 (?)

[From Richard Kennaway (981028.1540)]

Bill Powers (981028.0631 MDT):
>Repetitive cycles. We need to control them to sing or play music, recite
>poetry (doggerel, anyway), walk or run, push someone on a swing, pound
>nails, saw wood, jack up a car, paint a wall, or write a list like this.
>Many of them are tied to natural physical rhythms like gaits, but many are
>not -- they're rhythmical because at this level speed of repetition is the
>main controlled variable.
>So, does this level go between events and relationships, or does it replace
>events? Try it on, let me know what you think.

I just read this and haven't had time to do any thinking, but just before I
dash off on travels until Monday, I thought I'd mention that I've just
added some walking behaviour to my simulated insect, which I haven't posted
anything about for a long time. It consists of a rhythmic cycle of actions
with the legs. Pick up front legs, move them forwards, put them down. Pick
up middle legs, move them forwards, put them down. Pick up rear legs, move
them forwards, put them down. Repeat. "Walking" arises from the fact that
the bug tries to control its body position so as to remain vertically above
the centre of its footprint, and parallel to the best-fit plane through its
feet. Turning around is done similarly, by swinging pairs of legs
clockwise or anticlockwise.

As yet, this behaviour is not part of the control of any perception, but
just a blind cyclic program. However, if pointed in the direction of a
staircase it can successfully walk up and down without losing its balance.
Oh yes, for those who have seen earlier versions of the Bug, I've added a
variety of different terrains for it to walk over.

Running on a 400 MHz Pentium II, this has a big Wow! factor. You can
actually see it walking and struggling to keep its balance on the stairs,
with the animation running at upwards of 150 frames per second.

Coming next will be control systems which will use the walking and turning
routines to make the bug steer towards a visual landmark.

The latest version is at
http://www.sys.uea.ac.uk/~jrk/JRKBug-1.1/BugApplet.html. It's a Java applet
which in principle should run in any Java-equipped web browser (running
Java 1.1 or later). It works with Internet Explorer, but Netscape has
problems, I don't know why. It also needs a powerful computer with a
fairly big screen. If you want to download files to run it locally (which
will make no difference to the speed, but means you can use an applet
runner instead of a web browser), the only ones you need are BugApplet.html
and AppletClasses.jar. If your applet runner doesn't understand jar files,
you need to get all the *.class files instead.

No time to document all the zillions of controls, but for those who may
have a suitable machine, here is what you need to do after loading the
applet to make it walk up and down stairs:

1. Click on the "Parameters" button, and set the following values in the
scroll bars:

Anim. step: 0.001 (this is the time interval of the simulation, in
seconds -- 0.001 is the minimum possible. Larger values may cause
instability due to bad approximation.)

Walk step: 0.1 (this is the time between successive actions in the
walking cycle)

2. Click on the "Terrain" button, then click on the "Staircase" button.

3. Click on the "Walk" button, then click on the "Walk fwd." button (or
"Walk back", "Turn right", or "Turn left").

4. Click on the "Run" button to set it going.

5. For added fun, click on the "Switches" button, then click on any of the
resulting left-hand column of buttons to shoot legs off. If it walks fast
enough and the parameters are tuned right, it can walk with just its front
and rear legs.

Colleagues here get excited when they see it. It's only 5000 lines of
Java. Half of that is the user interface, half of the remainder is the
physical simulation. The most difficult thing to get across to people is
that the bug knows nothing about how to walk over uneven terrain or up and
down stairs. The only thing it is doing is executing that cycle of leg
actions and attempting to keep its body centered over its footprint. It
doesn't even know implicitly in any meaningful sense, because when I added
the new terrain types, I hardly had to change the bug at all to make it
walk over them. It didn't work at first (it fell over), but I eventually
found that all I had to do was give it longer legs and reduce the
simulation time step (and it may be that reducing the simulation time step
would have been enough on its own).

-- Richard Kennaway, jrk@sys.uea.ac.uk, http://www.sys.uea.ac.uk/~jrk/
    School of Information Systems, Univ. of East Anglia, Norwich, U.K.

Date: Wed, 28 Oct 1998 11:45:16 -0800
From: Philip Runkel <runk@OREGON.UOREGON.EDU>
Subject: Level 5

>From Phil Runkel on 28 Oct 98 in response to Bill P's of same
date concerning level 5:

         An artist, to contribute a new view, must be able to see
what the rest of us cannot see. A scientist likewise. I was
charmed to see, through your description, what so many of us
would not have seen even if we had looked at that video or a
hundred other rats or videos.
         But is it possible to look at a rhythmic repetition as a
repeated program or as a sequence of programs?

         Although I welcome your postulated levels, if only to show
so clearly the kind of inclusiveness relation that must exist
among the levels, I often wonder whether the hierarchy that every
individual builds as it grows into maturity is measurable
different from others. Or whether miniature hierarchies are
built every hour to suit a miniature situation. I am thinking
here of modeling that you and Marken and Bourbon have done that
contains tiny hierarchies. Often I can put one of your labels on
one of those levels by then cannot put another of your labels on
the adjacent level in that tiny hierarchy.

         It is always a pleasure to watch you think. Or intuit. Or
invent. And same to you, Mary.


And here the post that never made it to CSGnet:

Date: Thu, 29 Oct 1998 21:46:11 +0100 (MET)
Message-Id: <199810292046.VAA18528@luna.worldonline.nl>
To: team@forsselltrans.com
From: fxplooij@worldonline.nl (F.X. Plooij)
Subject: level 5 and tapes

Dear Dag and Christine,

Yes the tapes have arrived in good order. Thank you very much. I am very
glad with it. One can learn a lot from it. It is always a bit of shock to
see oneself perform and one learns what not to do anymore next time.

This discussion about level 5 is very interesting. One of the new skills one
can observe from appr. 17 weeks onwards is the ability to recognize 'tunes'
such as the opening tune of the 5th of Beethoven. So, my bet would be that
this is an aspect of fifth order of perception and control. The following
part is taken from the manuscript I am preparing for our new "Journal of
Perceptual Control Theory":

"Schindler (1989) observed the �cerebral peep' in children of 16-18 weeks.
This peep typically occurs in regression periods in vocalization signalling
the start of a new developmental stage. Although babbling (%Oller, 1986:
�canonical babbling; %Stark, 1986: Reduplicated babbling; %Landberg &
Lundberg, 1989: Reduplicated consonant babbling) is first produced by most
children around six months, it may be observed as early as 18 weeks
(%Koopmans-van Beinum & Van der Stelt, 1986; and personal communication).
Only the latter is relevant for our purposes. The same is true of the very
beginnings of sitting and crawling, which have been reported to occur around
4 and 5 months, respectively (Rosenblith, 1992%, p. 314).

Synchronous with their acquisition of babbling, infants also make rhyhmic
banging of objects they are manipulating, and, moreover, the rhythms of
babbling and banging have the same period or interval between the repeated
movements. They are paced by the same intrinsic clock.

Just as these repeated movements are structured in time, human action is
segmented in relatively narrow time windows of a few seconds at the first
level of goal-oriented behavior (%Kien, 1994; %Kien & Altman, 1995;
%Schleidt & Kien, 1997). This is a universal phenomenon in human action
which has its beginning around the age of 4 months. Phrases of speech
carrying a semantic content and divided by pauses all fall within the time
domain of a few seconds (%Schleidt & Kien, 1997). Different mammalian
species show comparable segmentation of a few seconds in their movement
patterns. This is a compelling indication that similar neuronal processes
underlie the generation of mammalian movement.

Adult human perception is similarly segmented in time spans of approximately
3 seconds (%P�ppel, 1997). This is illustrated by the following findings,
taken from %Schleidt & Kien (1997). Segmentation on the order of a few
seconds was first discovered in human perception by psychophysical studies
that provided evidence of 'short time constants'. ... Time estimation up to
3 seconds is rather good, after that it becomes quite bad. ... A Necker cube
tends to alternate with a peak around 3 seconds. .... Western television
directors (and video and film editors) - probably unconsciously - use time
spans of mostly 2-3 seconds to structure film events, no doubt reflecting
the preferences of the television viewers. ... Human perception is not
continuous but in discrete quanta. ... Other authors have also suggested
that the inflowing information is broken down into a string of sequential
units (Fodor et al., 1974; Fraisse, 1985; Garner, 1974). Michon (1977,
p.191) writes about "the concept of psychological present" .... And, last
but not least, most of the musical themes in the music of Haydn, Mozart,
Beethoven, Brahms, and Mahler are in the range of a few seconds.

The latter example brings us back to babies. Infants as young as 4.5 months
are sensitive to the integrity of musical phrase structure (%Trehub &
Trainor, 1990). Infants were presented with a listening choice between
Mozart minuets with pauses between the phrases or within such phrases. The
infants exhibited listening preferences for musical samples that preserved
the appropriate musical phrase structure (i.e., between-phrase pauses),
while they had not been familiarized with the original or intact sequences.
The same authors report that some parallels are evident in recent research
on running speech. For example, infant-directed speech that is manipulated
by the insertion of pauses within clauses disrupts infant attention more
than pauses inserted between clauses, an effect that is absent in
adult-directed speech. %Krumhansl & Jusczyk (1990) used a visual preference
procedure to examine 6- and 4�-month-old infants' sensitivity to phrase
structure in music. Sections of Mozart minuets were divided into segments
that either did or did not correspond to the phrase structure of the music.
Infants in both age groups listened significantly longer to the
appropriately segmented versions. Their behavior accorded well with
judgments of the same materials made by adults, suggesting that protracted
musical experience may not be necessary to perceive phrase structure in
music. 4.5-Month-olds preferred to listen to their own names over foils that
were either matched or mismatched for stress pattern (%Mandel, Jusczyk &
Pisoni, 1995). The results indicate when infants begin to recognize sound
patterns or sound �events' of items frequently uttered in the infants'

Musical acculturation from infancy to adulthood was studied by %Lynch,
Eilers, Oller & Urbano (1990) by testing the abilities of Western
6-month-olds and adults to notice mistunings in melodies based on native
Western major, native Western minor, and non-native Javanese pelog scales.
Results indicated that infants were similarly able to percieve native and
non-native scales. Adults, however, were generally better perceivers of
native than non-native scales. These findings suggest that infants are born
with an equipotentiality for the perception of scales from a variety of
cultures and that subsequent culturally specific experience substantially
influences music perception. The support for this "innateness" hypothesis
challenges the antithetical hypothesis which suggests that western scales
should be inherently easier to perceive, because their intervals approximate
small-integer frequency ratios. In similar vein, children appear to settle
on the L1's repertoire of sounds within half a year of birth (%Kuhl,
Williams, Lacerda, Stevens & Lindblom, 1991)."

This literature is discussed in the section concerning level 5.

Best wishes,
Frans Plooij


Date: 07:14 PM 11/4/1998
To: "f.x.plooij" <fxplooij@worldonline.nl>
From: Forssell Translation Team <team@forsselltrans.com>
Subject: Events
Cc: Bill Powers <powers_w@frontier.net>


Many thanks for your draft. It sure adresses the event level and gives a
lot of meaty insight.

I took the liberty of sharing it with Bill P. He found it very interesting.

May I post it to CSGnet?

The current continuing discussion of levels would benefit.

How about posting it yourself? I do not know if you listen in to CSGnet.

Best, Dag

Date: Fri, 6 Nov 1998 11:13:17 +0100 (MET)
Message-Id: <199811061013.LAA28472@luna.worldonline.nl>
To: Forssell Translation Team <team@forsselltrans.com>
From: fxplooij@worldonline.nl (F.X. Plooij)
Subject: Re: Events

Dear Dag,
it is a good idea to post my draft myself to the CSGnet. When we moved house
I dropped out and I have to connect again. I'll try and, if this goes well,
will post it. Otherwise, I'll come back to you for help.

Best wishes,

Well, that never happened, but here is Frans' post at long last.

Best, Dag

Dag Forssell
dag@forssell.com, www.forssell.com
23903 Via Flamenco, Valencia CA 91355-2808 USA
Tel: +1 661 254 1195 Fax: +1 661 254 7956