  Speech prosody enables communication of emotional intentions via modulation
of vocal intonations. Reciprocal interactions between superior temporal (STG)
and inferior frontal gyri (IFG) have been shown to anchor a neural network for
prosodic comprehension, which we refer to as the Prosody Neural Network (PNN).
Although the amygdala is critical for socio-emotional processing, its integral
functional and structural role in processing social information from speech
prosody as well as its role in the PNN is largely unexplored including
inconsistent recent empirical findings. Here, we used magnetoencephalography
and diffusion magnetic resonance imaging of white-matter pathways to establish
that the PNN is characterized by (1) a robust amygdala-cortical functional
connectivity that dynamically evolves as prosodic interpretation progresses,
(2) direct structural fiber connections between amygdala and STG/IFG traversing
a ventral white-matter pathway, and (3) robust amygdala-insula functional
connectivity and structural insula fiber projections to arcuate STG-IFG
connections. These findings support a role for functional and structural
amygdala-centric ventral pathways in combining speech features to form prosodic
percepts. They also highlight insula contributions to prosodic comprehension,
potentially via vertical integration of amygdala-centric ventral processing
into dorsal pathways responsible for prosodic motor articulation and speech
planning.
