Predict future learning accuracy by the structural properties of the brain, an in vivo longitudinal MRI study in songbirds

Abstract

Human speech and bird song are acoustically complex communication signals that are learned by imitation during a sensitive period early in life. Although the neural networks indispensable for song learning are well established, it remains unclear which neural circuitries differentiate good from bad song copiers. By combining in vivo structural Magnetic Resonance Imaging with song analyses in juvenile male zebra finches during song learning and beyond, we discovered that song imitation accuracy correlates with the structural architecture of four distinct brain areas, none of which pertain to the song control system. Furthermore, the structural properties of a secondary auditory area in the left hemisphere, are capable to predict future song copying accuracy, already at the earliest stages of learning, before initiating vocal practicing. These findings appoint novel brain regions important for song learning outcome and inform that ultimate performance in part depends on factors experienced before vocal practicing.