Science & the bar-press

[From Erling Jorgensen (960613.1420)]

Rick Marken (960610.1330)

Rick, your post to Bruce Gregory reminded me of something I had
wanted to pass on to Bill P. and Bruce A. about the rat data
they're accumulating.

These disturbances are hard to see because, when control is
good, they usually have little effect on the result: the bar goes
down every time, for example. It look like a bar press is just
"emitted". It's hard to see that the organism is actually pressing
in a slightly different way each time _in order to_ get the bar

This is the point Bill made a while back, from watching some video
excerpts, when he described the repeated pawing at the bar a rat
was making. I stumbled across a reference on PsychLIT that seems
to refer to the same realization:

Gallo, A., Duchatelle, E., Elkhessaimi, A., LePape, G., et al.
(1995). Topographic analysis of the rat's bar behaviour in the
Skinner box. _Behavioural Processes_, 1995 Mar., Vol. 33(3),

The PsychLIT abstract reads as follows:

"Videotaped and studied the behavior of 38 male rats submitted
to a continuous reinforcement in a Skinner box. Ss displayed 14
different behavioral patterns close to the bar. It was found that
the increasing frequency of the bar press, generally considered
a unitary response was, in fact, due to summation of the
development of several different behavior frequencies. A CAH
analysis distinguished 5 behavioral categories. The frequency
of each category varied throughout learning according to the
number of sessions before criterion. Thus, learning in the
Skinner box would result from an association of the reinforcers
with the successive units of behavior shown by animals at the
bar whose sequential organization and nature change according
to acquistion rapidity." (AN: 82-31940)

While the authors are finally noticing the _changing means_ of
accomplishing the event of a "bar-press," I'm not sure they go
far enough with their new insight. It sounds as though they
have rearranged the one supposedly unitary behavioral event into
14 new behavioral events or patterns, and then recategorized
these into 5 clusters. So now we know scientists can frame and
categorize. Whether any of these patterns or clusters are
perceptions the rats are actually controlling remains to be

I haven't read the actual article, but I thought it might be
partial confirmation from "the mainstream" of something PCT
has been trying to say for a long time. Good luck, if anyone
wants to follow up on this.