Functional MRI: brain plasticity, brain disease and functional recovery.

Brain plasticity may be defined as long-term alteration in behavior related activity of distributed neural systems. Functional imaging, and particular ly functional MRI, allows to investigate the mechanisms underlying brain pl asticity. Two aspects may be distinguished : one is learning in healthy sub jects; the other is functional reorganization following or associated with acute or chronic brain injury. Because functional MRI is totally non invasi ve, it appears well suited to follow such reorganization over time. This th eme will be developped in the following text.