title: Cross-modal plasticity preserves functional specialization in posterior parietal cortex.
abstract: In congenitally blind individuals, many regions of the brain that are typically heavily involved in visual processing are recruited for a variety of nonvisual sensory and cognitive tasks (Rauschecker 1995; Pascual-Leone et al. 2005). This phenomenon-cross-modal plasticity-has been widely documented, but the principles that determine where and how cross-modal changes occur remain poorly understood (Bavelier and Neville 2002). Here, we evaluate the hypothesis that cross-modal plasticity respects the type of computations performed by a region, even as it changes the modality of the inputs over which they are carried out (Pascual-Leone and Hamilton 2001). We compared the fMRI signal in sighted and congenitally blind participants during proprioceptively guided reaching. We show that parietooccipital reach-related regions retain their functional role-encoding of the spatial position of the reach target-even as the dominant modality in this region changes from visual to nonvisual inputs. This suggests that the computational role of a region, independently of the processing modality, codetermines its potential cross-modal recruitment. Our findings demonstrate that preservation of functional properties can serve as a guiding principle for cross-modal plasticity even in visuomotor cortical regions, i.e. beyond the early visual cortex and other traditional visual areas.
authors.affiliation: Center for Mind/Brain Sciences (CIMeC), University of Trento, Italy.
authors.forename: Angelika
authors.initials: A
authors.lastname: Lingnau
authors.forename: Lukas
authors.initials: L
authors.lastname: Strnad
authors.forename: Chenxi
authors.initials: C
authors.lastname: He
authors.forename: Sara
authors.initials: S
authors.lastname: Fabbri
authors.forename: Zaizhu
authors.initials: Z
authors.lastname: Han
authors.forename: Yanchao
authors.initials: Y
authors.lastname: Bi
authors.forename: Alfonso
authors.initials: A
authors.lastname: Caramazza
mesh_terms: D000328:Adult; D001132:Arm / Q000502:physiology; D001766:Blindness / Q000503:physiopathology*; D001921:Brain / Q000503:physiopathology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D009434:Neural Pathways / Q000503:physiopathology; D009473:Neuronal Plasticity; D009778:Occipital Lobe / Q000503:physiopathology; D010296:Parietal Lobe / Q000503:physiopathology*; D011434:Proprioception / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*
keywords: congenital blindness; cross-modal plasticity; proprioceptively guided reaching