Auditory cortical plasticity: a comparison with other sensory systems

The auditory cortex has a crucial role in higher cognitive functions, inclu ding the perception of speech, music and auditory space. Cortical plasticit y, as in other sensory systems, is used in the fine tuning of the auditory system for these higher functions. Auditory cortical plasticity can also be demonstrated after lesions of the cochlea and it appears to participate in generating tinnitus. Early musical training leads to an expansion in the r epresentation of complex harmonic sounds in the auditory cortex. Similarly, the early phonetic environment: has a strong influence on speech developme nt and, presumably,on the cortical organization of speech. In auditory spat ial perception, the spectral cues generated by the head and outer ears vary between individuals and have to be calibrated by reaming, which most proba bly takes place at the cortical level. The neural mechanisms of plasticity are likely to be the same across all cortical regions. It should be useful, therefore, to relate some of the findings and hypotheses about auditory co rtical plasticity to previous studies of other sensory systems.