> Yes, these are very interesting findings. But do they mean that activation >of
visual cortex is interpreted as somatosensory input? Or does this >represent some
kind of visual imaging? In either case, since visual cortex >does not light up during
tactile tasks in patients blinded later in life, it >would seem that no CHANGE in
function from visual to somatosensory >occurred. GSD
Not necessarily for both cases. The fact that there is a difference between
congenitally blind patients and those blinded later in life seems to indicate to
me that there is an influence of critical period plasticity on this effect.
I agree that, with respect to those blinded later in life, there seems to be
no change in function from visual to somatosensory, because there is no
activation of primary visual cortex during braille reading in these patients.
Such large-scale cross-modal plasticity may be a product of developmental
plasticity during a critical period and not due to reorganizational changes
associated with adult plasticity.