Affiliations: Institute of Experimental Psychology,
Heinrich-Heine-University, Düsseldorf, Germany
Note: [] Address for correspondence: Professor Dr. Petra Stoerig,
Institute of Experimental Psychology II, Bldg.23.03, Universitätsstr.1,
D-40225 Düsseldorf, Germany. E-mail: [email protected]
Abstract: The current doctrine regards fields of partial cortical blindness as
permanent once a temporally restricted window for spontaneous recovery has
passed. Accordingly, neuropsychological rehabilitation mainly applies
compensatory procedures that train patients to make better use of their sighted
field. The more ambitious goal of functional recovery depends on the survival
of pathways that continue to transmit retinal information from the blind field.
Although wide-spread antero- and retrograde degeneration follows lesions that
destroy or denervate the primary visual cortex and cause partial cortical
blindness, several retinofugal pathways survive in cats, monkeys, and humans.
In all three species, they subserve a variety of visual functions which develop
and improve with practice. Post lesion plasticity is greater when the lesion
occurs early in life, but changes in behavioural performance and brain
responses have also been demonstrated in late lesion subjects. Although the
extent of functional improvement is variable, and the most effective approaches
still need to be established across cohorts, the evidence for perceptual
learning in fields of cortical blindness indicates that the visual processes
mediated by the surviving parts of the visual system can be harnessed to
improve functional outcome.
Keywords: Primary visual cortex, degeneration, post lesion plasticity, age at lesion, blindsight, perceptual learning, cortical blindness, functional recovery
