Is it possible to define NVLD in terms of
CHC?
(I recommend reading part one, the previous
post, before reading this one).
In order to define NVLD in terms of CHC, we'll look at
the steps of learning disability definition according to Flanagan's model,
using CHC theory. Since I haven't found
literature dealing directly with this subject, I'll try to use the information
presented in the previous post.
Step 1: Significantly low achievement
in reading/ reading comprehension/writing/written expression/mathematics. It's probable that NVLD
children will have significantly poor achievement in math and maybe also in
reading comprehension and written expression.
But as stated in the previous post, this criterion is not always met in
NVLD children. When it's not met, the
child is not learning disabled. Mammarella &
Cornoldi write, that contrary to other learning
disabled children, the academic weaknesses of children with NVLD may be
moderate and not dramatic. So it's possible,
according to these authors, that the label NVLD is not correct (at least in
these cases). The authors suggest the
name "specific nonverbal disorder" or "specific visuospatial
disorder". In case the child meets
the first step, it's possible to move on to the next step:
Step 2: One (or more) cognitive ability is
significantly below average. NVLD children may have poor Visuospatial Processing
, Processing Speed, and maybe lowered Fluid ability. They also may have poor Working Memory. As for Long Term Storage and Retrieval, NVLD
children may poor Free Recall (of visual stimuli, for instance in the
RCFT). Probably not all these abilities
will be lowered simultaneously in each NVLD child. In the 2012 CHC model (see the first
presentation in the series "Intelligence and Cognitive Abilities" in
the right hand column of this blog), there are more cognitive abilities that
are likely to be lowered in NVLD children: Psychomotor Speed, Psychomotor Ability,
Tactile Ability and Kinesthetic Ability.
Step 3:
There is a logical or an empirical connection between the poor academic
achievement and the low cognitive abilities. This criterion may be met in an NVLD child
having mathematics difficulties that can be explained by poor Visuospatial Ability. Reading comprehension difficulties can be
related to poor Fluid Ability (in the aspect of integration of parts into a
whole and understanding implicit meaning in texts).
Step 4: Most cognitive abilities are
intact. NVLD children are
likely to have intact Comprehension Knowledge and Auditory Processing, as well
as intact Memory Span. As for Long Term Storage and Retrieval, most narrow abilities are likely to be intact
(Free Recall of auditory stimuli, Naming Facility, Ideational and Word fluency,
Meaningful Memory). It's possible that Fluid
Ability will also be intact, especially if assessed with nonvisual tests. When the lowered abilities are Visuospatial Processing
and Processing Speed and the other
cognitive abilities are intact, this criterion is met.
Step 5: Exclusionary factors
(insufficient instruction, immigration, emotional difficulties etc.) are not
the main reasons for the poor academic achievement. It's possible that NVLD
children will have emotional and social difficulties that are secondary to the
cognitive disabilities and are not a main reason for the poor academic
performance.
To summarize, there certainly will be children with
symptoms of NVLD that we can diagnose as learning disabled using this
definition, within CHC theory. Other
children, presenting most symptoms but without significantly poor achievement
in reading, writing and/or math, will not be diagnosed as learning disabled,
not according to the CHC definition, nor according to any other learning
disability definition.