Expectation-based decoding of ambiguous speech

Introduction: Accounts of predictive coding suggest that the brain continuously anticipates upcoming sensory events in order to reduce ambiguity by integrating incoming information with prior knowledge. The transient nature of spoken utterances should make speech a prime example of a process depending on prior information. We conducted an fMRI study involving a delayed-match-to-sample task with pairs of normal and degraded sentences. Methods: The degraded sentences merely contained the prosodic parameters of the original sentence and were therefore physically incomprehensible. Importantly, they could suddenly be…