Bruce Abbott (2010.02.08.1320 EST)
BA: Relying on second-hand descriptions of someone’s
theory always carries the risk of getting it wrong, or only partly right, so
I’d like to interject a few things that Jaak Panksepp wrote in his book Affective
Neuroscience that may apply here. The following is from Chapter 10, which
covers rage and anger.
BP: Emotion is not an either-or process.
It’s not a “response” that either occurs or doesn’t occur. It’s a
state of body and mind that ranges over a continuum from peacefully dozing in a
hammock to charging an opponent, all restraint removed, with the intent to
kill. To get from one extreme to the other, it passes through all the
intermediate states. Only in pathological cases does it snap from nothing at
all to the maximum possible degree.
BP: Pathological cases – and ESB.
Electrical stimulation is usually on-off, and it tends to be violent. If the
current or the frequency of stimulus spikes were gradually reduced, the animal
would be seen to pass smoothly from the high extreme back down to the lowest
level of arousal, or so I would predict. I would not predict that as the
stimulation is reduced, the animal would continue throwing itself at the bars
of the cage without regard to pain or exhaustion, trying to kill the
experimenter, and then at some threshold level, suddenly relax, curling up and
purring itself to sleep.
BP: In your description, there is one
variable you don’t mention:
my previous post, I indicated the sections quoted from Panksepp’s Affective
Neuroscience by (1) introducing them in the immediately preceding
paragraph, and (2) Using indents rather than spaces to separate the paragraphs
of the quoted text from one-another. The block of quoted material was then
separated from my own comments by a space. [Perhaps this wasn’t clear to
you, in which case I accept the blame if you became confused as to whose
writing was whose.]
The paragraph immediately below, attributed to me,
was written by Panksepp.
My own initial experience with this technique was especially revealing. When I
first applied ESB to a cat that had been surgically prepared with an indwelling
electrode in the medial hypothalamus, within the first few seconds of ESB the
peaceful animal was emotionally transformed. It leaped viciously toward me with
claws unsheathed, fangs bared, hissing and spitting. It could have pounced in
many different directions, but its arousal was directed right at my head.
Fortunately a Plexiglas wall separated me from the enraged beast. Within a
fraction of a minute after terminating the stimulation, the cat was again
relaxed and peaceful, and could be petted without further retribution.
BP: That certain sounds like an on-off reaction: either the animal was
viciously attacking you, or it was relaxed and peaceful. But you don’t mention
how the stimulation was applied. I would guess that the ESB was turned on and
off by a switch, so the signal was either zero or maximum. When on, the
magnitude of the ESB was evidently large enough to drive the reference signals
hard against their maximum values. What would have happened if instead of an
on-off switch, you had had a knob with which you could gradually increase the
stimulation from zero? Do you suppose that at the first picoampere of current,
the animal would have charged you in all-out rage? I rather doubt that. If you
know different I would be wrong, but I’ll bet that was not tried.
haven’t done any of this ESB research, but my impression from reading
about it is that lower levels of stimulation produce lower levels of
activation, just as you suggest. At low levels, you might see the cat hiss and
bare its teeth, but not leap at someone’s face.
Of course it’s possible that the stimulation wasn’t confined to reference
signals. I’d be surprised, in fact, if it didn’t disturb a lot of different
kinds of signals at various places in the control loop. If perceptual signals
were generated, and it’s hard to imagine how that could be avoided, those
signals follow paths that bifurcate, going not only into the comparators at the
same level but passing upward into the perceptual input functions of
higher-level systems. This means that disturbances would appear in higher-level
control systems, possibly quite extreme disturbances as the perceptual world
was suddenly altered by large amounts. Considering that as many as 1000 neurons
can be found in one cubic millimeter of brain tissue (and many more than that
in a cat, where, I’ve read, the neurons are a tenth the size of human neurons),
and that the geometric details of neural function vary widely from animal to
animal, it seems highly unlikely that placement of electrodes by stereotaxis
could aim the stimulation at a precisely known neural function without spilling
over into relatively large volumes of brain tissue. Also, we mustn’t forget,
electricity flows through closed paths, so the current at the tip of an
electrode flows on through all sorts of other structures after it has done its
job where the experimenter aimed it.
and everyone else who has done ESB research is aware of the potential spread of
stimulation well beyond the intended target. That’s why other, more
localized techniques have been developed, such as delivering pico-amounts of a
specific neurotransmitter, blocking agent, etc. to specific brain locations. These
techniques allow one to zero in on specific target neurons; however, I don’t
know what work has been done using these techniques to refine or refute the
conclusions Panksepp draws from the ESB data.
The sudden cessation of the aggressive-looking action is a clue to something
else. How often have you had a really strong emotion, realized it was based on
a mistaken perception, and instantly returned to a normal calm state? I would
guess never. Strong emotions taper off as the adrenaline gradually dissipates
or is metabolized; the heart pounds on for more than few second or minutes; the
breathing gradually slows down; the trembling in the limbs gradually lessens
and smoothes out. The mental upsetness slowly departs. Emotions don’t simply
switch on and off; the physiological changes can’t be reversed that quickly. A
small fraction of a minute isn’t long enough to recover from all the
physiological changes involved, especially if the emotion is violent rage.
So I am led to suspect that what you saw was “behavioral emotion” –
that is, the visually-observable configurations, transitions, events, and
relationships typical of high-error situations, but without the somatic changes
that normally accompany emotional activity. I don’t see how a complete recovery
from an extreme emotional state could occur so fast: " Within a fraction
of a minute after terminating the stimulation, the cat was again relaxed and
peaceful, and could be petted without further retribution." That makes
even higher-order involvement unlikely; the attack is more like a stickleback
attacking any red blob. The cat attacked a moving object; you shouldn’t take it
agree that the observations are open to that possible interpretation, although it’s
just as speculative as the possibility that Panksepp offered. After all, nobody
measured the cat’s heart rate or circulating levels of adrenalin; the cat
may have appeared to be relaxed while still experiencing elevated levels of
I’d guess that using the electrode, you were hijacking the same means of control
that the cat’s higher-order systems would operate under normal conditions, but
without the normal higher-order control going on (other than resisting
disturbances), and without the normal somatic changes that accompany strong
emotions. An actor can produce the appearance of emotion that way without
necessarily experiencing the whole emotion at all the levels that are normally
involved. Even actors may require a little time to recover, since the good ones
do feel some of the physiological changes, and some have problems with shedding
the persona for a long time afterward. But it’s nothing like a complete
That’s exactly how I would
interpret it, except that I have no problem imagining that it’s the whole
“rage” emotion system that’s been artificially brought into
action, either by over-riding a reference or producing a disturbance that the
system would act to counter. Why do you insist that it can’t be the
complete emotion that is brought into play?
Several investigators called aggressive displays induced by ESB “sham
rage,” based on the assumption that the animals were not experiencing
true affect. This seemed plausible because some of the subjects could be petted
even while they were hissing and snarling. However, such sites appear to be
quite low in the brain stem and in the minority. Now it seems more likely that
most electrode placements above the mesencephalon do evoke a central state
indistinguishable from normal anger (except perhaps for the fact that
stimulation-induced rage is not sustained for a long time after ESB offset,
perhaps because of the sudden release of an opponent process).
No, I don’t buy it. Everything points to sham rage, by which I would mean the
production of visual and auditory configurations, transitions, and
relationships (observable by a human experimenter) without the normal
higher-order motivation or the normal lower order physiological changes. I
don’t think you can draw correct conclusions simply by watching a cat from
outside its skin. I can’t prove the rage isn’t “real”, whatever that
means, but you can’t prove it is.
Everything points to sham rage? We can’t get into the cat’s
head to know what it was experiencing, so all we have are the cat’s
behaviors to go by. According to the description, everything one might expect
to go with genuine rage was present. What points to sham rage is only the
relatively quick recovery of an apparently docile state once the stimulation
ceased. That could point to shame rage, but other explanations are possible.
Perhaps the most compelling evidence that ESB evokes a true
affective feeling is that humans stimulated at such brain sites have reported
experiencing a feeling of intense rage.
That strongly suggests that there are higher-level perceptions disturbed by the
stimulation of lower systems as I conjectured above, and that the perceptions
are recognizeable as emotions. The implication is that in the cats as well as
the humans, you were disturbing a lot more than the mesencephalon.
having difficulty parsing your meaning here. The stimulation that produces
feelings of rage is at the level of the medial hypothalamus (and certain other
structures of the limbic system that feed into it). So yes, the stimulation at
that level was disturbing (or changing references for) a lot more than the
mesencephalon. Electrodes in the latter produce only certain components of the
reaction. It’s just what one might expect to find if there’s a
hierarchy of levels of control.
It would be interesting to know whether, in the human
beings, the intense feeling of rage ceased instantly when the current was
switched off, or if there were continuing jitters from adrenaline, pounding of
the heart, rapid breathing, and so on. If those things didn’t happen (and I
should think they would be mentioned if they did), then the perception of rage
was false, being the result of electrical stimulation of the same higher-order
perceptual pathway that would have been stimulated by such physiological
changes. The subjects experience rage-ness, but not rage.
The human case that Panksepp
referred to was reported in another paper by another researcher. I’ll see
if I can find it. But if the person cannot distinguish “rage” from “rage-ness,”
where is this distinction getting us? Is it somehow crucial to the PCT-based
theory of emotions that it not be true rage? I must confess that I don’t
see it that way.
I really think that all this so-called information about emotions is just too
sketchy and superficial to be taken seriously. You didn’t know anything about
PCT when you conducted the experiment with the cat; you can’t be blamed for not
having any ideas about subtler possibilities, or for taking the appearances for
granted. Neither can the others, though I do wonder why some of these
considerations were not brought up. It’s as if everyone is used to taking
superficial appearances as “prima facie” evidence when in fact they
aren’t evidence at all, but illusions.
those were Panksepp’s observations, conclusions, and speculations, not
mine. I agree that they cry out for reinterpretation in control-theoretic terms.
However, I have a bit more faith in the soundness of the observations (and
their interpretation in terms of an innately-organized emotion system) than you