Speech chunking

In a recent study, Ding et al. (2016) showed that spectral peaks of brain waves corresponded to multiple levels of linguistic structure (e.g., peaks in the delta and theta range corresponded to the phrase and syllable rate, respectively). Because no acoustic/prosodic cues at this time scale were present, the peaks in the delta range must be generated internally. What does the presence of those brain waves tell us? Two equally valid interpretations can be offered: (i) they reflect cortical tracking based on syntax, generated by a built-in hierarchical oscillatory mechanism, or (ii) they reflect fumes of information transit at the end of decoding (at the phrase and at the syllable level), not necessarily the product of oscillators. The aim of this MEG study is to resolve this oscillations/fumes conundrum, and, furthermore, to test the influence of external cues such as prosody versus top-down processing on this mechanism. The study builds on a behavioral study (Ghitza, 2016) that measured the accuracy of digit retrieval.