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Re: [ontolog-forum] Semantic Dementia

To: "'[ontolog-forum] '" <ontolog-forum@xxxxxxxxxxxxxxxx>
From: "Rich Cooper" <rich@xxxxxxxxxxxxxxxxxxxxxx>
Date: Wed, 20 Nov 2013 11:33:51 -0800
Message-id: <97D77E9B3E1042B39DEAC167EDC97F1F@Gateway>
Thanks John,    (01)

I find their hub-and-spoke model very interesting
when trying to understand how the brain uses
language, sensors and effectors in such flexible
ways:    (02)

>From their paper:
                To account for the global,
pan-modal involvement of the ventrolateral ATLs in
conceptual knowledge, we have developed an
alternative framework for conceptual knowledge
termed the "hub-and-spoke" model (Lambon Ralph et
al., 2010, Patterson et al., 2007, Pobric et al.,
2010 and Rogers et al., 2004). This model holds
that in addition to modality-specific sources of
information ("spokes") and their
inter-connections, representation of conceptual
knowledge requires an integrative "hub". The hub
uses information from the modality-specific spoke
regions to develop modality-invariant, conceptual
representations that capture deeper patterns of
conceptual similarity across all sensory-motor and
verbal modalities. These integrated
representations are necessary because similarity
in any particular sensory-motor domain is, at
best, only a partial guide to conceptual
similarity (Dilkina and Lambon Ralph, 2013, Lambon
Ralph et al., 2010 and Smith and Medin, 1981). For
example, though apples and bananas have different
shapes, colours and tactile properties and are
manipulated in different ways, the conceptual
system must be able to recognise that they are
similar types of object. In addition, true
conceptual representation requires the integration
of properties that are experienced in different
times and situations, and representation of the
complex, non-linear relationships between the
concept's verbal and nonverbal modality-specific
properties and its conceptual significance (see
Lambon Ralph et al., 2010 for more detailed
discussion of these issues). The hub-and-spoke
framework holds that the ATL hub provides this
critical aspect of conceptual representation
through the formation of representations that
integrate information from all
sensory-motor-verbal domains. When this region is
damaged, as in SD, the result is a breakdown in
the complex boundaries that define different
concepts, such that semantic decisions come to be
made on the basis of superficial characteristics
rather than their deeper conceptual properties.
For example, SD patients may reject "emu" as an
example of a bird but simultaneously over-extend
the concept to accept "butterfly" (Lambon Ralph et
al., 2010 and Mayberry et al., 2011).    (03)

                Previous work on the function of
the ventrolateral ATLs has focused on their role
in representing existing knowledge and its
progressive deterioration as a result of ATL
atrophy in SD (e.g., Binney et al., 2010 and
Rogers et al., 2004). The hub-and-spoke framework
also predicts that the ATLs play a key role in the
acquisition of novel concepts (Rogers &
McClelland, 2004). There is already some support
for this idea from electrophysiological studies in
primates. The response properties of anterior
inferior temporal neurons change as monkeys learn
novel associations between visual stimuli,
suggesting a role for this region in the
acquisition of concepts (Albright, 2012). In the
present study, we tested this hypothesis in humans
by studying acquisition of new conceptual
knowledge in patients with SD. The hub-and-spoke
model predicts that the ATLs are critical for
integrating the various sensory features of an
object into a unified, coherent conceptual
representation that can be generalised to new
exemplars. We tested this prediction by training
SD patients to recognise novel visual stimuli as
members of two categories. Previous research has
shown that SD patients are able to apply
well-defined rules to classify novel stimuli, when
the classification rule is provided by the
experimenter (Koenig, Smith, & Grossman, 2006).
Here, we tested the patients' ability to acquire
more complex category structures that could not be
captured by a simple rule and when no information
about the nature of the categories was supplied by
the experimenter.    (04)

There are a lot of good papers on
sciencedirect.com.  One more that looks related to
ontology is:    (05)

http://www.sciencedirect.com/science/article/pii/S
0950705113002098    (06)

The second paper is titled: "Conceptual
Recombination: A method for producing exploratory
and transformational creativity in creative works"    (07)

What Chomsky called "productivity of language"
seems to be more of a creative construction of
linguistic expressions.  So a mechanism for
creating linguistic elements and combining them
into new elements probably involves some degree of
creativity.      (08)

-Rich    (09)

Sincerely,
Rich Cooper
EnglishLogicKernel.com
Rich AT EnglishLogicKernel DOT com
9 4 9 \ 5 2 5 - 5 7 1 2
-----Original Message-----
From: ontolog-forum-bounces@xxxxxxxxxxxxxxxx
[mailto:ontolog-forum-bounces@xxxxxxxxxxxxxxxx] On
Behalf Of John F Sowa
Sent: Tuesday, November 19, 2013 11:29 PM
To: ontolog-forum@xxxxxxxxxxxxxxxx
Subject: Re: [ontolog-forum] Semantic Dementia    (010)

Rich and John,    (011)

RC
> a quote from the abstract of the article:    (012)

From:
http://www.sciencedirect.com/science/article/pii/S
0010945213002517
> "Patients learned to assign abstract visual
stimuli to two categories.
> The categories conformed to a family resemblance
structure in which
> no individual stimulus features were fully
diagnostic; thus the task
> required participants to form representations
that integrate multiple
> features into a single concept. Patients were
unable to do this,
> instead responding only on the basis of
individual features."    (013)

Thanks for the citation.  That article mentions
the anterior temporal
lobes as critical "in acquiring new conceptual
knowledge."    (014)

For a survey of the brain regions and their
functions in language
and reasoning, see slides 25 to 30 of    (015)

    http://www.jfsowa.com/talks/goal2.pdf
    Psycholinguistics and Neuroscience    (016)

This is "Chapter 2" of the slides on "Goal of
language understanding."
I split up that huge collection into more
manageable "chapters" and
added a few more updates.    (017)

RC
> The way they describe the deficit sounds to me
that the loss was
> in deduction, specifically in integrating each
of the spokes into
> a coherent response based on all the spokes.    (018)

The frontal lobes are more directly involved in
reasoning (of which
deduction is an important aspect).  Your next
comment is more accurate
in citing the defect in perception and
interpretation.    (019)

RC
> When concepts had multiple spokes, (attributes
or properties in
> ontolog talk), the patients couldn't use
multiple properties,
> and relied on just one instead, leading to
errors of perception
> and interpretation.    (020)

Any defect in those functions would certainly
affect deduction.    (021)

JMC
> The interplay of topic maps and taxonomies,
within one's mind,
> surely complexify explanations for this
[semantic dementia].    (022)

Yes.  Slides 25 to 27 of goal2.pdf say more about
these interactions.
In slide 25, the line marked
"Frames/slide/Schemata" points to an
area in the parietal lobe called "Geschwind's
area."  That area,
which is also called the inferior parietal cortex,
is critical
for cognitive maps that relate and interpret
semantic info from
any sources.    (023)

John Sowa    (024)

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