From Aaron Sloman Thu Sep  3 05:55:45 BST 1998
To: PSYCHE-B at LISTSERV.UH.EDU
Subject: Re: Theories of consciousness and MPD (The architectural basis)

Cc: drwatt at classic.msn.com,dawso007 at MAROON.TC.UMN.EDU

Doug Watt wrote Date: Mon, 31 Aug 1998
[DW]
> 1) Strongly agree with Bernie Baars that the empirical evidence is
> overwhelming that MPD is a real and not an iatrogenic disorder and that a
> position of complete disbelief and dismissal should raise some questions
> about the dismisser's assumptions ....

with much else of interest discussed below.

To which George Dawson responded Date: Tue, 01 Sep 1998
[GD]
> I think that the lines of evidence to support MPD and associated
> mechanisms of dissociation and repression are actually far less
> compelling.

> This has been a historically long and divisive debate.  The
> constructs of both repression and dissociation have been controversial.
> ....

> ...
> I think a lot of the bias in the consideration of MPD from a clinical
> perspective comes from the treatment of real people with the disorder.
> There are a group of clinicians who believe that this is an
> extraordinary condition that requires extraordinary treatment measures.
> There is another group (where I include myself) who recognizes that
> people with dissociation and MPD-DID need treatment, but that standard
> methods properly applied are quite successful.

> ....

A multi-pronged attack on this problem (or set of problems) may be
helpful. Most readers of this list will appreciate the need for both
clinical investigations and for attempts to find neural underpinnings.
Some will also appreciate the need for conceptual analysis to help
clarify the questions that are being discussed and to ensure that
arguments do not proceed at cross-purposes.

There is a fourth approach that may be useful: explore information
processing architectures that may be capable in principle of explaining
various types of normal human mental functioning and then see whether
they admit the possibility of specific sorts of abnormalities if
stressed or damaged or developmentally disadvantaged in some way.

A useful slogan is: don't expect to understand "abnormal" cases until
you know how the "normal" system works, in considerable detail. Only
then can you know what sorts of things can go "wrong", etc.

This exploration of architectures can be more or less constrained by
various kinds of evidence, and various kinds of requirements, e.g.
evolutionary plausibility, requirements for learning, requirements for
social interaction, requirements for neural implementability, etc.

In recent postings to this group I've sketched ideas about a
coarse-grained multi-layered architecture, within which I think some
of the phenomena of MPD are to be expected. In this architecture there
are various components which evolved at different times in response to a
variety of evolutionary pressures. In particular the sketch includes
(at least) the following concurrently active mechanisms:

  (1) a layer containing a collection of very old "reactive" mechanisms,
      e.g. in the cerebellum, brain stem, spinal cord, etc. ("reactive"
      needs careful definition, but I'll not do that now.)

  (2) a layer containing a collection of somewhat newer and less
      biologically widespread "deliberative" mechanisms -- requiring a
      variety of supporting mechanisms, including motive generators,
      associative memory, inference mechanisms. ("deliberative" also
      needs careful definition.)

  (3) a meta-management layer which can (to some extent) monitor,
      evaluate, and redirect processes in the other layers (and itself?)

  (4) one or more (possibly trainable) global "alarm" systems which can
      very rapidly detect patterns in sensory data or internal
      processing and deterine whether those patterns indicate problems
      or opportunities which require rapid redirection of activities in
      many parts of the architecture.

  (5) multi-layered sensory (perceptual) mechanisms, providing different
      sorts of information about the environment, at different levels of
      abstraction, to the previous layers and alarm systems. (Likewise
      proprioceptive sensors).

  (6) multi-layered motor mechanisms controlled by the previous layers.
      Actions may be initiated at different levels of abstraction.
      Sometimes the global alarm systems can grab control of the
      effectors.

The deliberative and meta-management mechanisms in humans seem to make
use of frontal lobe sub-systems. The global alarm mechanisms apparently
use the brain stem, the limbic system, and maybe more specialised
state-switching mechanisms in the frontal lobes. (I am only summarising
things I've read, possibly inaccurately: I am no expert on brains.)

NOTE:
I've pointed out previously that three different classes of emotions can
be associated with reactive, deliberative and meta-management
mechanisms, and shown how the presence of a meta-management system with
access to intermediate sensory databases can (in intelligent,
reflective, animals), lead to recognition of and theories about qualia,
etc. (This is loosely related to the global workspace theory.)

I think phenomena related to some types of MPD are to be expected in the
normal functioning of the meta-management system. Other phenomena may
require serious metamanagement malfunction. I'll try to explain.

1. It seems that humans are not born with all these architectural
sub-mechanisms fully fledged. Rather they develop during childhood. E.g.
it takes a while before a child develops the ability to attend to its
own motives or learns that they can be evaluated (e.g. as selfish or
not, imprudent or not, and in some cultures as sinful or not, etc.)
Likewise it takes a while before a child discovers it can remember and
use the contents of its thought processes and motives a short while
previously. (Before that happens wise parents can defuse some kinds of
nagging by distracting a child. When the architecture is more developed
and the child has learnt how to use it, e.g. by reviving temporarily
suspended concerns, that ruse fails.)

2. There are good engineering design reasons why the behaviour of the
metamanagement layer (e.g. the criteria used for self evaluation, the
strategies for redirecting attention, the strategies for invoking
deliberative processes, etc.) should not be rigidly fixed, but should be
capable of (a) varying from one context to another, and (b) developing
in sophistication over time (e.g. using more and more abstract
characterisations of mental processes.)

For instance, different types of self awareness and self control
are required when relaxing with friends, when looking after one's
children, when working with colleagues in the office, when playing a
team game like soccer.

This suggests a need for a mechanism which can detect changes of context
and switch clusters of categories, rules, strategies, motivations into
or out of the meta-management sub-system.

Perhaps we could describe this as a "personality switching mechanism".
(Examples of its operation are very familiar: the person who is a
sensitive, loving and caring individual with his/her family, and a cold,
calculating, ruthless ambitious individual at work. (Or vice versa.)

This switching between control structures in the meta-management system
is very crudely analogous to "context" switching in a multiprocessing
computer which time-shares different sorts of processes on a single CPU.

In a typical computer the architecture provides a collection of
"hardware" central control mechanisms, such as registers, instruction
counters, cache memories, etc. which can be occupied by different
"software" according to what the current task is.

Evolution may have got there first, though with a much more complex and
subtle mechanism.

In humans these changes of style or strategy according to context, can
happen without the individual noticing that they do, even when it is
evident to others (e.g. switching to an obsequious style in the presence
of the boss).

There are individual variations.

A "rigid" person will be too inflexible about changing and may have too
few "personalities" available for dealing with different situations. At
another extreme a person may be too unpredictable, too volatile,
switching between control regimes on the slightest provocation and not
necessarily selecting useful subsets in all (or most) situations.

Other possibilities include people who have a collection of effective
control regimes, but have not developed good ones for dealing with all
the commonly occurring contexts. In mild cases the person may simply be
awkward or embarrassing to deal with (in some contexts), and in extreme
cases totally unable to relate to others and maybe even dangerous.

So far, all I've described is a collection of more or less normal and
familiar phenomena with a hint at an architecture which could account
for them (though there's much I have not explained).

However, in more extreme cases this very same architecture could go
wrong in various ways, some of which would support and explain ideas
about multiple personalities.

For example, normally switching contexts does not disallow access to
(episodic) memories of events and actions in other contexts. However,
the change of context will involve a change in criteria for directing
attention, and as a result things that are important in one context may
be forgotten or go unnoticed in another. I.e. memory access mechanisms
and perceptual mechanisms are context sensitive. (I once failed to
recognize my niece from London when she turned up unexpectedly in my
office in Brighton. I thought she was a student with a vaguely familiar
face, whose name I could not remember.)

In an extreme case the accessibility of cross-context memories might be
severely impaired, either because of a neural abnormality of some kind
or because the "software" of the context mechanism has developed in a
way that prevents information from different contexts being accessible
at the same time. (There are many mechanisms which could achieve this
within a content-addressable memory mechanism, e.g. using
context-sensitive indexing mechanisms.)

In that case there would be a collection of relatively independent,
mutually uninformed, subsystems which take it in turns to be in the
meta-management role. (For a very loose analogy think of loading
different files into a word processor, or into the same spread-sheet
package. Sometimes communication between file contents is possible,
sometimes not, depending on the system).

In some cases the accessibility barriers could be asymmetric: in context
A, information about context B is accessible, but not vice versa,
possibly because of the type of indexing used or because of how
attention is controlled in the different contexts, or ....

A more extreme pathology could arise if the early developmental process
gets damaged in such a way that instead of one meta-management system
developing which can at different times be "occupied" by different
"software packages", the system grows several meta-management mechanisms
in parallel, which thereafter vie for control, possibly unequally.

Speculating wildly (partly inspired by discussions I have had with Doug)
I wonder whether this could happen if severe maltreatment during the
early stages of the development of the meta-management layer (the first
few years of childhood) might lead to a partially grown sub-system being
left unfinished because it doesn't produce good results, Then another
one might be "sprouted", which is also abandoned when partly developed
etc.

If this sort of thing happens there could be a number of concurrently
active incipient meta-management structures with only a subset ever
managing to gain complete control from time to time.

This would require a neurodevelopmental mechanism which is partly
controlled by innate mechanisms and partly by the degree of success and
failure of interaction with the environment (including other people).
(Is that an accurate characterisation of early brain development in
altricial species?)

(Compare mechanisms involved in regeneration of capabilities after
damage in adult life?)

If all the above is correct we could expect to be able to distinguish

(a) varieties of MPD which have to do with a not very extreme extension
of normal mechanisms for switching "personalities" according to context

(b) varieties of MPD which actually have abnormal, possibly stunted,
physiological structures implementing various partly developed
meta-management mechanisms which compete with one another for control
(not necessarily on equal terms!).

Cases of type (a) might be treatable by various kinds of therapy which
train the patient's switching mechanisms to get better at classifying
situations and turning on appropriate sets of perceptual strategies,
evaluation criteria and responsive behaviours.

Cases of type (b) may be impossible to restore to full normality, though
it's possible that some sort of treatment might enable one of the
meta-management mechanisms to develop furhter while the others atrophy
and lose their ability to interfere with the main one. I have no idea
what sort of therapy could do this.

It has occasionally struck me that the above ideas might be closely
related to phenomena like hypnotism, mass hysteria, religious ecstasy,
"possession" by spirits, etc.

I wonder whether readers who actually meet and treat people they
classify as having multiple personalities find any of the above ideas
help them understand actual cases they have encountered.

I think these ideas resonate strongly with many of Doug's claims, e.g.

> That MPD-DID is occasionally faked, often hyped, etc., is by no means
> the same as proving that it doesn't exist.

I'd add: and it may exist in several different forms, depending on
whether the basic information processing architecture has been
"deformed" or whether a normal architecture is being "used badly".

> The real reason for the skepticism is the profoundly disturbing
> implications for a unitary self/identity and a unitary stream of
> consciousness, both of which we take for granted ...

Which se should not do if the sort of information processing
architecture I've described is at work.

> There can be more hypnotic ability and less trauma, or less
> hypnotic ability and more trauma in my experience.

Differences which might be explained in part by the difference between
context switching in one meta-management system and concurrent
competition between different meta-management systems.

> That we are willing and able to divide the global workspace to avoid
> terror and horror at a young age seems to me anyway to be an
> empirically established fact.

That suggests frequently switching the occupancy of the single
meta-management system with little communication between occupants.

However, an alternative in some cases might be abandoning the partly
grown neural architecture and starting another one.

> Why we see that as having little direct implication for the possible
> intrinsic relationships between emotion and consciousness is harder to
> understand  ....

The use of the word "emotion" to label the types of implicit evaluations
of success or disaster (or awfulness) which influence very early
developmental trajectories may be misleading insofar as these are very
different from the kinds of things we call "emotion" in normal adult
life, which presuppose an already developed successfully functioning
architecture, e.g. being apprehensive in the face of anticipated danger,
grieving for a lost friend, being proud of an achievement....

What they all have in common is the powerful role of evaluation in
control mechanisms, and large scale redirection of processing.

> the outline of important connections between HC, nRt, nucleus .....
> etc. ....
> might eventually provide some way of understanding the genuine
> islands of awareness, the local workspaces that are partially
> segregated within the global workspace of a divided personality system

And also the varieties of context switching in a normal personality
system?

> we are talking about a fairly long time span, a "working identity"
> analogue to working memory that has a much longer time frame than any
> WM.

Yes. the "working memory" would be only a portion of the whole
meta-management mechanism. (Likewise individual registers in a computer
can change their contents rapidly between less frequent global context
switches.)

> But there are no good neural network models.

However, requiring the models to work at the level of the neural
networks may be a mistake. E.g. some of them might involve higher level
virtual machines which do not map onto neural architectures in any
simple way. And chemical processes may play important roles (e.g.
changes of mood, and modulating various forms of decision making, etc.)

> What is not clear is how differential affective states prime
> the "retrieval" of different alters, with the alters having such a
> degree of non-access to episodic memories formed by other alters.

If I am right, some of this may be just an extreme application of a
useful normal mechanism for context switching, driven not only by
affective states but also by detection of changes in the environment.
Other cases may require suppression of competing concurrent subsystems.

> These later (and what I consider) truer diseases of consciousness
> reflect much more than the stripping out of modular processors and
> their contributions to qualia, but instead show more fundamental
> alterations and disturbances in self, qualia, and working memory (esp.
> relevant to the nature of delirium  .....

There are different ways in which the very complex mechanism outlined
above can go wrong. Some have to do with losing or gaining accessibility
to contents of various sensory buffers (qualia), some to do with various
malfunctions or abnormalities in the processing of the contents. More
dramatic cases involve malfunctions in the higher order control
mechanisms as opposed to just the contents of what is controlled.

I.e. I agree with Doug that there must be many different sorts of
"diseases of consciousness" all needing to be explained, pointing to
different aspects of the architecture and ways they can go wrong.

cheers.
Aaron
=====
Aaron Sloman, ( http://www.cs.bham.ac.uk/~axs/ )
School of Computer Science, The University of Birmingham, B15 2TT, UK
EMAIL   A.Sloman@cs.bham.ac.uk
Phone: +44-121-414-4775 (Sec 3711)       Fax:   +44-121-414-4281
See also
    ftp://ftp.cs.bham.ac.uk/pub/groups/cog_affect/0-INDEX.html
