MARVIN MINSKY, THE EMOTION MACHINE , chapter 3
  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  (Simon & Schuster, Nov. 2006) http://web.media.mit.edu/~minsky/

[Comments in square brackets are my own thoughts.]


3. Being in Pain
~~~~~~~~~~~~~~~~

Minsky's main points here are that

@ a pain response is the activation of resources concerned with
  stopping the pain, and shutting down or lowering the priority
  of other resources; this may lead to cascades of unpleasant
  secondary effects;

@ there are various stages of pain, depending on severity,
  duration, and many other factors; he distinguishes 
  - momentary pain, not leading to suffering;
  - suffering and anguish due to extended pain, and its
    effects in limiting our choices;

@ there are various strategies for overriding pain, to some 
  degree;

@ chronic pain that serves no apparent purpose may be a "programming
  bug" -- something due to the late development of thinking, and
  insufficient time to evolve ways of countering the debilitating 
  cascade of mental effects that chronic pain has; [I'm not sure
  what it would mean for the "bug" to be fixed: All long-term pain
  disappears after a few weeks? That could be dangerous. Specific
  types disappear, such as neuralgia or auto-immune disorders
  (rheumatoid arthritis, lupus)?]

@ we learn how to avoid pain by developing "critics" that
  warn that what we are doing or considering doing is fraught 
  with risk;

@ switching on and off of critics (en masse) may account for
  bipolar disorder; in general, it accounts for moods;

@ negative learning -- learning of critics -- is underrated and
  understudied in psychology; [Hmm, isn't there a lot of work
  on rats and shocks? Maybe he means humans.]

@ to some extent we can motivate ourselves to endure some
  discomfort or pain in pursuit of some longer-range goals
  by "fooling ourselves", imagining possibilities that inspire
  or anger us into continued pursuit of the goals.

Here (on the second page of the chapter) and elsewhere in the 
book (esp. ch.9) Minsky briefly addresses what David Chalmers 
calls "the hard problem" -- explaining the *experience* of pain, 
rather than the mechanisms of pain. But I think he simply doesn't 
understand what Chalmers is getting at, i.e., the subjectivity 
of phenomenal experience, and the intuition that intelligent 
behavior could just as well occur without conscious sensations. 
Why should learning to avoid situations that are damaging to 
oneself involve *feeling pain*, rather than just dispassionate 
evaluation of damage as "strongly dispreferred"? Ironically, 
every time Minsky addresses the issue of qualia -- which only 
exist in a subjective perspective -- he answers, yes, they *can* 
be explained, and then proceeds to sketch an objective account!
Basically he says that pain sensations are not primitives, but
can be analyzed in terms of complex interacting parts, such as
the goal of stopping the pain, and the cascade of cognitive
consequences particularly in prolonged pain.

Mental pains induced by prolonged physical pain
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Among the cognitive consequences of prolonged pain he lists

- Anguish of losing mobility
- Resentment of not being able to think
- Dread of becoming disabled and helpless
- Shame of becoming a burden to friends
- Remorse at dishonoring obligations
- Dismay at the prospect of failure
- Mortification of seeming abnormal
- Terror of further decline and death

[But while these obviously can occur as side-effects, I don't
think they are *part* of the pain itself -- they just add further
burdens -- various mental pains.]

The machinery of suffering
~~~~~~~~~~~~~~~~~~~~~~~~~~
He diagrams the brain's body-maps and mentions some of the brain
regions involved in pain, but points out that such subsystem
identification doesn't really explain anything, until we can say
what processing these subsystems are doing.

An interesting observation is that our perception of internal
pains are much less specific and localized than surface pains
because evolutionarily, it wouldn't really have been helpful.
You can protect a hurt finger in quite specific ways, but you 
can't protect an inflamed appendix except perhaps by protecting
the entire belly and staying inactive.

[I wondered about his mention of the "limbic system", which acc.
to some of our readings has lost some credibility as an identifiable 
system, and his main ref is from 1965...]

He mentions "pain asymbolia" -- a condition where pain is felt
quite clearly, but without being experienced as unpleasant
[recall also the effects of Demerol]. He thinks this is because
somehow the pain is failing to cause the "cascade of torments"
(mental anguish) [but I don't see that this would deprive the
pain of its *physical* unpleasantness; somehow Minsky is trying
to blame the unpleasantness of pain on its creation of mental
pain, but I don't see that this explains anything.]

Feeling, hurting, and suffering
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Under this heading he addresses the issue of why feelings are
so hard to describe, again claiming that it's not because they
are so simple but because they are so complex. [But why should 
  we have particular difficulty describing feelings and other 
  sensations, while being able to describe our thoughts on politics, 
  or our evaluation of a movie, etc.? Aren't these just as complex?
  I'm more with McDermott here; the issue is not whether the 
  underlying *processes* are simple or complex, but whether our
  *symbolic models* of them are simple or complex. Note, for example,
  that judging a rose to be red may be an extremely complex process,
  in terms of what happens in the eye and in the brain, and in
  addition we may have various complex *associations* with that
  perception -- e.g., think of a painter working with various shades
  of red, or writers of phrases such as "Oh, who will kiss her 
  ruby lips", or "Hair so red, red as flame" (respectively from
  a song and from a romance writer's overwrought pen); but that
  doesn't mean the *concept* of "red" is complex in our model of
  our perceptions.]

He also again talks about *experiencing* pain here, and again
blames the badness of pain on the resultant mental pains. But
he does make the interesting claim that avoidance of injury and
taking care of injuries couldn't be learned through positive 
reinforcement -- it requires negative feelings, [If one imagines
  trying to build a robot that learns strictly through positive
  reinforcement, one can see the difficulty: for instance, suppose
  we designed the robot so that if it receives a leg injury, it
  will get considerable pleasure from treating the leg with great
  caution and care, until it is healed (or repaired). Wouldn't that
  lead to appropriate responses to injury? Well no -- it would
  probably try to get injured, so as to enjoy the feeling of
  caring for the injury! Can we do better by designing the robot
  to get pleasure from injury *avoidance* -- i.e., it gets positive
  reinforcement whenever it perceives that it *might* have been
  injured, but didn't get injured? Well, it would *still* seek out
  dangerous situations, since otherwise it'll have no sense of
  having avoided injury! So perhaps we want to build it so that
  the safer from injury it feels itself to be, the happier it is.
  But then, what would prevent it from neglecting an *accidental*
  injury? This may be solvable, but it doesn't look easy... or can
  we just "shift the origin" on the scale of negative and positive
  feelings, so that all feelings are just more or less positive,
  never negative? Then even an injured creature or robot would be
  feeling not-too-bad, yet would be striving strenuously to get help
  and/or take measures to promote healing of the injury, wouldn't
  it? Or would it?? If the shift in origin causes no behavioral 
  change, then the robot (analogously, a person) would still behave
  as if suffering, yelling for help, etc., when injured or otherwise
  in trouble, so it seems that the pain would not have been banished
  after all!]

Overriding pain
~~~~~~~~~~~~~~~
He talks about various ways of partially overriding pain:
- focusing on something else
- focusing analytically on the pain
- establishing a counter-irritant
- taking comfort from someone else similarly afflicted
- self-discipline, pain-training [I think of "A Man Called Horse"]

He also makes his point about the evolutionary "programming bug"
here, in connection with chronic pain.

In a subsection on grief, he mostly cites the wisdom of Shakespeare,
e.g., in making grief more tolerable by thinking of the loss in
more positive terms.

Critics (Correctors, Suppressors, and Censors)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
He notes that while we make many dubious decisions, we rarely do 
things with disastrous consequences to ourselves, like sticking a 
finger in one's eye, or telling strangers how ugly they are.

He argues that much expertise consists of knowing what NOT to 
do, and that this expertise consists of resources that he calls
"critics" -- specialized recognizers of particular kinds of
mistakes. He thinks some of them intervene during a dangerous
action, others at its start, others before the action is even
considered. They operate at all of the "levels" from instinctive
ones to self-awareness. [I find this too speculative and unsupported
  to be of much value. Minsky has advocated critics throughout his
  research life, and one of his students, Gerald Jay Sussman, did
  a thesis on programming or planning by creating an initial program 
  or plan more of less randomly, and then applying critics to it to
  repair errors and inadequacies. But while this was an interesting
  idea, more systematic approaches have been more successful so far, 
  where "critics" are replaced by flaw-dection/correction algorithms
  based on a general logical analysis of the structure of plans 
  and the interactions of their parts. Flaw detection/correction 
  is simplest in the case of SAT (satisfiability-based) planning:
  a flaw is an unsatified logical formula, and a correction step 
  consists of "flipping a bit" (the truth value of a propositional 
  variable) so as to reduce the number of unsatisfied formulas -- 
  though randomization to escape from local nonzero minima may be 
  necessary.]

He goes on to speculate further about where critics might play an 
important role: 
- mood swings
- humor is often about what one should not do, flouting the critics
- decision-making may be the result of critics calling a stop to
  further exploration of alternatives;
- perception of (personal?) beauty may depend on suppression
  (by critics) of awareness of flaws [is he thinking of "love is
  blind" here?]
- learning how and why failures occur in complex situations;
- breaking out of local maxima;
- enduring suffering for the sake of long-term benefits
- mystical euphoria may be a state where all critics are turned
  off, causing muddled vague thoughts to seem like profound
  insights;

  [But I get impatient here, because of the lack of concreteness.
  I don't see that we need "critics" as special processes. Instead,
  it may be sufficient to suppose that we learn CAUSAL CONNECTIONS -- 
  and if certain causal consequences are evaluated as hurtful or
  otherwise bad, we will plan our actions to avoid taking actions
  with those consequences, just as we will favor actions that we
  believe will have rewarding consequences. The willingness to
  endure some suffering for the sake of long-term goals can be
  explained by assuming that plan evaluation is cumulative -- i.e.,
  we do whatever seems to give the greatest OVERALL rewards in the
  long run, not the greatest immediate gratification (though we
  probably do temporal discounting, to allow for the uncertainty of
  the future). I don't see that the concept of critics -- ubiquitous
  unspecified, special-purpose procedures -- shed any real light on
  this.]

The Freudian sandwich
~~~~~~~~~~~~~~~~~~~~~~
He pays homage to Freud's ideas, particularly the idea that our
instinctive drives (coming from the "id") often conflict with our
acquired ideals (coming from the "superego"), and are arbitrated 
by methods that settle conflicts (coming from the "ego"); and to 
the idea that avoiding or managing conflict depends on *repression*,
*sublimation*, or *repudiation* of impulses. Repression mechanisms
keep undesirable impulses from entering consciousness, sublimation
allows them limited expression in some other guise, and repudiation
allows them into consciousness, but repudiates and neutralizes them
there.

  [All this, to me, remains very speculative.]


Emotional exploitation
~~~~~~~~~~~~~~~~~~~~~~
The heading refers to tricking ourselves with fictitious ideas
in order to overcome ennui in problem-solving, where those ideas 
get us sufficiently riled up or energized to continue. [I have
  no introspective evidence for anything of the sort, so I'm a bit
  puzzled. One thing I noticed is that he refers to "Work" and "Sleep"
  as resources; of these, "Work" seems far too broad and vague a term
  for us to figure out what a resource actually does, and how.]

He concludes with some truisms about imagining, e.g., "to think about 
changing the way things are, we have to imagine how they might be".
This should raise issues in symbolic representation, but at least at
this point it doesn't, for Minsky.

He thinks we need to trick ourselves into pursuing certain goals 
when we would rather be doing something else, because if we found
it too easy to switch goals at will, we might act in ways that
imperil us. This would be an evolutionary disadvantage.