Cross-modal plasticity preserves functional specialization in posterior parietal cortex

Cereb Cortex. 2014 Feb;24(2):541-9. doi: 10.1093/cercor/bhs340. Epub 2012 Oct 31.

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.

Keywords: congenital blindness; cross-modal plasticity; proprioceptively guided reaching.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Arm / physiology
  • Blindness / physiopathology*
  • Brain / physiopathology
  • Female
  • Humans
  • Magnetic Resonance Imaging
  • Male
  • Middle Aged
  • Motor Activity / physiology*
  • Neural Pathways / physiopathology
  • Neuronal Plasticity*
  • Occipital Lobe / physiopathology
  • Parietal Lobe / physiopathology*
  • Proprioception / physiology*
  • Visual Perception / physiology*