Affiliations: Division of Neuroanatomy and Brain Development,
Department of Neuroscience, Karolinska Institutet, S-17177 Stockholm,
Sweden | Institute of Neuroinformatics, 8057 Zürich,
Switzerland | Institute of Developmental Physiology, 19127 Moscow,
Russia | Pediatric Neurology Service, CHUV, 1005 Lausanne,
Switzerland
Note: [] Correspondence to: Prof. G.M. Innocenti, Dept. of Neuroscience,
Karo-linska Institute, Doktorsringen 12, plan 5, S-17177 Stockholm, Sweden.
Abstract: MS is a little girl who suffered severe, bilateral destruction of
her primary visual areas at six weeks, after premature birth at 30 weeks.
Between the ages of 4.5 and 5.5 years she partially recovered different aspects
of visual function, and, in particular, the ability to segregate fig-ures from
background, based on texture cues. The recovery might have been due to the
compensatory role of the remaining visual areas that could have acquired
response properties similar to those of the primary visual areas. This is not
supported by the available FMRI (functional magnetic resonance imaging)
responses to visual stimuli. Instead, abnormalities in the pattern of
stimulus-induced changes of interhemi-spheric EEG-coherence in this patient
suggest that her visual callosal connections, and possibly other
cortico-cortical connections have re-organized abnormally. Since
cortico-cortical connections, including the callosal ones appear to be involved
in perceptual binding and figure-background segregation, their reorganization
could be an important element in the functional recovery after early lesion,
and/or in the residual perceptual impairment.
Keywords: Visual cortex, human, cat, ferret, corpus callosum, connections
