Cross Modal Re-Organization of the Auditory Cortex
Meredith and Allman (2012) report that "neural plasticity affords the brain the remarkable capacity for adapting to features of its sensory environment…."
The authors report that their findings based on young ferrets with induced early hearing loss demonstrates cross-modal reorganization within the auditory cortex. Specifically, neurons that typically respond to auditory input were shown to respond to somatosensory stimulation. Meredith and Allman note that previous researchers have unsuccessfully looked for core auditory cortex changes following early deafness, yet have successfully demonstrated secondary auditory cortex changes following early deafness. However, when other researchers used somatosensory stimulation, cross-modal plasticity was observed in humans (previously) and in animals (this study).
The present study demonstrates core auditory cortices exhibit cross-modal reorganization following early hearing loss secondary to somatosensory stimulation. The authors report their findings are consistent with the recently proposed "brainstem theory for cross-modal plasticity induced by hearing loss." The Brainstem Theory reveals that the auditory brainstem naturally receives cross-modal input prom the somatosensory systems at multiple locations. Further, neurons in the dorsal cochlear nucleus and the inferior colliculus are impacted by somatosensory stimulation.
For More Information, References, and Recommendations
Meredith MA, Allman BL.. (2012) Early Hearing Impairment Results in Cross-modal Reorganization of Ferret Core Auditory Cortex. Neural Plasticity 2012. Article ID 601591. doi:10.1155/2012/601591