Receptive awareness of prosody may be processed in the bilateral superior temporal sulcus.

Prosody is defined (Wikipedia) as "those elements of speech that are not individual vowels and consonants but are properties of syllables and larger units of speech. These contribute to such linguistic functions as intonation, tone, stress and rhythm. Prosody may reflect various features of the speaker or the utterance: the emotional state of the speaker; the form of the utterance (statement, question, or command); the presence of irony or sarcasm; emphasis, contrast, and focus; or other elements of language that may not be encoded by grammar or by choice of vocabulary."

As such, the rhythms, time patterning, and emphases of speech contain both verbal content and emotional content. It's not too surprising, therefore, that understanding the prosody of speech is processed bilaterally.



The cortical analysis of speech-specific temporal structure revealed by responses to sound quilts

Tobias Overath, Josh H McDermott, Jean Mary Zarate, & David Poeppel

Nature Neuroscience (2015) doi:10.1038/nn.4021

Received 08 February 2015 Accepted 20 April 2015 Published online 18 May 2015

Speech contains temporal structure that the brain must analyze to enable linguistic processing. To investigate the neural basis of this analysis, we used sound quilts, stimuli constructed by shuffling segments of a natural sound, approximately preserving its properties on short timescales while disrupting them on longer scales. We generated quilts from foreign speech to eliminate language cues and manipulated the extent of natural acoustic structure by varying the segment length. Using functional magnetic resonance imaging, we identified bilateral regions of the superior temporal sulcus (STS) whose responses varied with segment length. This effect was absent in primary auditory cortex and did not occur for quilts made from other natural sounds or acoustically matched synthetic sounds, suggesting tuning to speech-specific spectrotemporal structure. When examined parametrically, the STS response increased with segment length up to ~500 ms. Our results identify a locus of speech analysis in human auditory cortex that is distinct from lexical, semantic or syntactic processes.

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