# The cortical organization of speech processing **Abstract:** | 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. Understanding the functional anatomy of speech perception has been a topic of intense investigation for more than 130 years, and interest in the basis of speech and language dates back to the earliest recorded medical writings. Despite this attention, the neural organization of speech perception has been surprisingly difficult to characterize, even in gross anatomical terms. The first hypothesis, dating back to the 1870s1, was straightforward and intuitive: speech perception is supported by the auditory cortex. Evidence for this claim came from patients with auditory language comprehension disorders (today’s Wernicke’s aphasics) who typically had lesions of the left superior temporal gyrus (STG). Accordingly, the left STG in particular was thought to s **Authors:** [[Gregory Hickok and David Poeppel]]