Convergent vocal representations in parrot and human forebrain motor networks

DOI

Cortical networks for the production of spoken language in humans are organized by phonetic features, such as articulatory parameters and vocal pitch. Previous

research has failed to find an equivalent forebrain representation in other species. To investigate whether this functional organization is unique to humans, here we

performed population recordings in the vocal production circuitry of the budgerigar (Melopsittacus undulatus), a small parrot that can generate flexible vocal output,

including mimicked speech sounds. Using high-density silicon probes, we measured the song-related activity of a forebrain region, the central nucleus of the anterior

arcopallium (AAC), which directly projects to brainstem phonatory motor neurons. We found that AAC neurons form a functional vocal motor map that reflects the

spectral properties of ongoing vocalizations. We did not observe this organizing principle in the corresponding forebrain circuitry of the zebra finch, a songbird

capable of more limited vocal learning. We further demonstrated that the AAC represents the production of distinct vocal features (for example, harmonic structure

and broadband energy). Furthermore, we discovered an orderly representation of vocal pitch at the population level, with single neurons systematically selective

for different frequency values. Taken together, we have uncovered a functional representation in a vertebrate brain that displays unprecedented commonalities with

speech-related motor cortices in humans. This work therefore establishes the parrot as an important animal model for investigating speech motor control and for developing therapeutic solutions for addressing a range of communication disorders.

Authors:

Zetian Yang & Michael A. Long

Published: 2025

PMID: 40108457

Products:

P128-5

Research Area:

Motor System, Cognitive and Behavioral Neuroscience

Species/Model:

Zebra Finch, Parrot