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ACQ
uiring knowledge
in
sp eech
,
language and hearing
, Volume 11, Number 1 2009
19
MULTICULTURALISM AND DYSPHAGIA
system. The exercising of a cognitive capacity, such as
memory, supports its further development, and this develop
ment in turn allows more sophisticated organisation of
language – a sort of mutually expanding capacity and complexity
in language organisation. This is represented in the model by
an arrow spiralling outward through cognitive capacities and
the internal language system shown in figure 3.
The application of a cognitive capacity to the formation or
access of symbolic representations is the only way this
capacity can be observed, i.e. a child can only “attend” when
“attending to
something
”. Thus, while cognitive capacities are
conceptually distinct from language, they are functionally
interwoven, and impossible to separate out in real-life
situations. This is important for practice in that many sup
posedly language-free measures of cognitive functioning are
directly or indirectly dependent on language (Camarata &
Nelson, 2002). In our model, language is heavily dependent
upon the cognitive capacities, but is itself a discrete construct.
ing to spelling conventions (Leitão, 2001). For example,
“horse” may be linked with other words spelled with “or”
replacing the link with other words with the same rime but
different spelling. Throughout development, links between
related concepts/words form schemas or other efficient
organisational systems for thinking and communicating (e.g.,
see Reynolds, Sinatra & Jetton, 1996; Rumelhart, 1980). A
mature internal language system with multiple overlapping
organisational systems is considerably more complex than
can be represented in a drawing, so figure 2 only inadequately
captures the increasing complexity by the inclusion of an
arrow.
Sophisticated neural organisation according to relevant
features is the key to efficient retrieval of symbols (Camarata
& Nelson, 2002). Highly sophisticated and easily accessible
language symbols within efficient organisational systems are
required for thinking and for literacy. Factors in the environ
ment, the person’s genetic predisposition, the language
context, and the person’s emotional state impact on how an
individual forms, organises and accesses symbolic repre
sentations (see figure 5). The environment is important in
how/when/how many symbolic representations of concepts
are formed. Thus, poor health or limited communicative
opportunities can negatively impact on the development of
the internal language system. The individual’s response to
interaction and situational events, general well-being,
emotions and other factors all influence the formation and
organisation of symbolic representations. This organisation
has implications for efficient retrieval; failure to develop a
sufficiently detailed and well-organised representational
system may lead to difficulties or inefficient retrieval, i.e.,
language problems (Nash & Donaldson, 2005).
The link with visual images
A very close link exists between the symbolic representation
and the visual/image representation for that concept. A
longstanding debate about whether image and verbal
representations are separate, parallel or the one underlying
system, has been discussed in an enormous body of literature
which was beyond us to fully cover (e.g., Ley, 1983; Paivio,
1971). We considered the researchers’ very definition of
language
would influence their research methodology, and
that findings might depend upon how it was investigated.
Findings from positron emission topography (PET)
investigations suggest that largely the same parts of the brain
are activated for pictures and for words (Vandenberghe, Price,
Wise, Josephs & Frackowiak, 1996). Clark (2006) also
suggested that it is plausible that the internal language system
plays a mediating role in image storage and access. Rather
than trip on this early point, we decided simply to assume
that the visual image and symbolic representation are very
closely linked.
Links to cognition
We could find no widely used definition of
cognition
, even in
psychologists’ reviews of the literature (P. Clayton, personal
communication, 20 August 2006), so we used the term
cognitive capacities
for simple mental processes, and
thinking
for higher level, integrated mental process.
Cognitive capacities, such as memory and attention, are
necessary for the formation and organisation of symbols
(Flavell, Miller and Miller, 1993). In our model these cognitive
capacities are conceived of as a capacity of the brain structure,
rather than as entities. These capacities are drawn upon for
forming, organising and accessing the internal language
Cognitive capacities
Internal language system
Figure 3. An increasing spiral of cognitive capacity and internal
language complexity
Links to spoken and written codes
The internal language system is not observed directly; it is
neurologically situated and manifest only through spoken,
written and other codes. Spoken language symbols and
written language symbols are the material manifestations of
the same underlying language system in the brain (Clark,
2006). The written word is not a symbol for the spoken word.
They are both symbols for the one underlying concept
(although there is a relationship between the “form” of words
in the spoken and written codes). Other codes for com
municating, such as signs and pictorial symbols, are also the
material manifestation of the same underlying language
system. All forms of communicating and thinking use the
same internal language system as illustrated in figure 4. For
example, mathematic symbols are types of material symbolic
representations for concepts that are stored and organised
within the same internal language system as words (Clark,
2006). An individual’s experience of these material (i.e.,
manifest in the world) symbols and codes influences develop
ment, represented by the feedback arrow on the model. This
part of the model represents a specific challenge to common
representations of language by speech pathologists. Typically,
written language is considered as having material form (it can
be seen on the page), whereas spoken language is equated
with the internal language (and considered “immaterial”).
However, both spoken and written symbols can be measured
and should be considered as “material”. Much of the literature
outside speech pathology that we sourced stressed the
importance of distinguishing between the internal language
system and its material manifestation in the world: the actual
spoken and written symbols themselves (e.g., Clark, 2006).