The neural basis of speech perception - a view from functional imaging

Functional imaging techniques, such as Positron Emission Tomography (PET), functional Magnetic Resonance Imaging (fMRI), have enabled neuroscientists to elaborate how the human brain solves the formidable problem of decoding the speech signal. In this paper I will outline the properties of primate auditory cortex, and use this as an anatomical framework to address the data from functional imaging studies of auditory processing and speech perception. I will outline how at least two different streams of processing can be seen in primary auditory cortex, and that this apparently maps onto two different ways in which the human brain processes speech. I will also address data suggesting that there are considerable hemispheric asymmetries in speech perception.