Lecture | David Poeppel | Speech Is Special and Language Is Structured
I discuss two new studies that focus on general questions about the cognitive science and neural implementation of speech and language. I come to (currently) unpopular conclusions about both domains. Based on a first set of experiments, using fMRI and exploiting the temporal statistics of speech, I argue for the existence of a speech-specific processing stage that implicates a particular neuronal substrate that has the appropriate sensitivity and selectivity for speech (Overath et al. 2015). Based on a second set of experiments, using MEG, I show how temporal encoding can form the basis for more abstract, structural processing. The results demonstrate that, during listening to connected speech, cortical activity of different time scales is entrained concurrently to track the time course of linguistic structures at different hierarchical levels. Critically, entrainment to hierarchical linguistic structures is dissociated from the neural encoding of acoustic cues and from processing the predictability of incoming words. These results demonstrate syntax-driven, internal construction of hierarchical linguistic structure via entrainment of hierarchical cortical dynamics (Ding et al. 2015). The conclusions I reach — that speech is special and language syntactic-structure-driven — provide new neurobiological provocations to the prevailing view that speech perception is ‘mere' hearing and that language comprehension is ‘mere' statistics. (October 22, 2015)