Brain responses to spoken F0 changes: Is H special?

• Sudden rises in speaker F0 stimulate the attention orienting mechanisms.
• P300 and beta band activity are sensitive to a sudden rise in spoken F0.
• Stress and tone features correlate with signals that trigger attention orientation.

Across languages and linguistic phenomena, rises in spoken pitch seem to occupy a privileged position compared to steady F0 or pitch lowering. Speakers are more likely to use sudden rises in pitch to arouse listener attention, rather than using falls; e.g., contrastive stress, questions seeking a response, beginnings of units of discourse, expressions of intense emotion, etc. The study evaluated whether there are brain responses that are more sensitive to stepwise raised vs. lowered spoken F0, and whether any such responses were also caused by pure tone stimuli. Three types of brain response were evaluated. Mismatch negativity (MMN), which reflects pre-attentive mechanisms, was only sensitive to degrees of F0 change, and not to direction. P300, which is an indicator of attention orientation, did not show sensitivity to F0 direction to non­speech stimuli, but showed greater sensitivity to raised F0 than to lowered F0 in speech. Time–frequency analysis of EEG data showed beta-band response in the right parietal area, when presented with spoken F0 elevation. Taken together, the P300 and beta band results suggest that attention modulation mechanisms are triggered when listeners are exposed to sudden rises in spoken F0. However, there was a lack of attention orientation response when non-speech F0 changes were presented, or when subjects were exposed to lowering of F0 in speech.