Evoked potentials, which is a technique used in measuring
the electric activity of the brain through electrodes put on the head,
measured when learners are five years old robustly predicts eventual risks for
dyslexia, this was shown by Giraud and collaborators.
Finally, functional magnetic resonance studies show, before learning to read and
write, the density of the grey substance is rarefied in
the temporal region which (is) the region where reading occurs,
and that this region is less activated in children proving
to be dyslexic compared to non-dyslexic.
There is a sort of continuum between difficulties in oral
language development called specific language impairment, or SLI, and dyslexia -
most children with SLI will develop dyslexia afterwards,
will display subsequent reading difficulties.
In fact, we can say, to put it simply, that SLI is often co-occurring
with dyslexia, and that it's a sort of 'stronger form'
which start with difficulties with the oral language first,
then subsequently with the written language.