Our lab is currently focusing on the following research topics.

1. Understanding mechanisms underlying intrinsic motivation for vocal practice in songbirds.

Intrinsic motivation, which drives animals, including humans, to exhibit various voluntary behaviors, spontaneously originates within the brain without immediate external stimuli such as rewards or punishments (Fig. A below). Songbirds such as zebra finches offer a unique opportunity to study mechanisms of intrinsic motivation because they spontaneously produce many renditions of songs even in the absence of apparent recipients mainly for vocal practice (Fig. B below).  We are investigating neural mechanisms of intrinsic singing motivation using a behavioral paradigm that we recently established to enhance singing motivation (Kim et al. 2021, Sci. Rep.).  

2. Understanding physiological and behavioral mechanisms of dawn chorus in songbirds

Many species of songbirds sing vigorously in the early morning hours. This well-known occurrence is referred to as the "dawn chorus (DC)" and has been recognized as a significant biological indicator of the start of the day across the world since ancient times (Fig. A below). Despite its widespread presence, the functions and underlying mechanisms of the DC still hold many mysteries. Our research aims to comprehensively understand this mysterious behavior from both proximate and ultimate causes through interdisciplinary research that bridges neuroscientists and ecologists studying who study birdsong (Fig. B below). We are specifically examining the "warm-up hypothesis," a recently proposed explanation for the dawn chorus in wild birds (Schraft et al. 2017, Anim. Behav.). 

3. Understanding how songbirds modify and optimize their vocal performance using the basal ganglia-thalamo-cortical circuit and the auditory feedback.

Songbirds learn to produce complex vocalizations (song) using a discrete and specialized circuit called the anterior forebrain pathway (AFP, black circuit in Fig. A below), which is homologous to the mammalian basal ganglia-thalamo-cortical circuits  (Fig. B below).  We are trying to understand how the AFP influences the song motor pathway to improve song structure using electrophysiological, pharmacologial, and optogenetic approaches.

4. Understanding how categorical perception of vocal sounds is shaped by vocal learning in early life and how it crystallizes with age.

Both songbirds and humans are known to perceive their own vocal sounds categorically, and the categorical boundaries are often determined by the statistical distributions of vocal sounds to which individuals are exposed during vocal learning early in life.   By tutoring young songbirds with specific songs and testing their perceptual ability, we are trying to create an animal model in which we can study the experience-dependent development of categorical perception in early life at both the behavioral and neural levels.