In his model of speech production, Frank Guenther proposes the different parts of his model are in specific areas of the CNS -- claims that are somewhat controversial. However, to really evaluate these claims, we need to know something about what is known about the anatomy of speech production and perception. Greg Hickok has been working on this problem for a long time, and has definite opinions on the subject. His recent opinion/review article explains his hypotheses, and is also a good review of the evidence for what parts of cortex do what in speech production/perception. Tomorrow at Sensorimotor Journal Club, I will present his article:
Hickok, G., & Poeppel, D. (2007). The cortical organization of speech processing. Nature Reviews Neuroscience, 8(5), 393-402. (link to pdf of article)
Despite decades of research, the functional neuroanatomy of speech processing has been difficult to characterize. A major impediment to progress may have been the failure to consider task effects when mapping speech-related processing systems. We outline a dual-stream model of speech processing that remedies this situation. In this model, a ventral stream processes speech signals for comprehension, and a dorsal stream maps acoustic speech signals to frontal lobe articulatory networks. The model assumes that the ventral stream is largely bilaterally organized - although there are important computational differences between the left- and right-hemisphere systems - and that the dorsal stream is strongly left-hemisphere dominant.