Abstract
To examine the neural bases of co-speech gesture production and perception, using the animation narration task in a face-to-face condition, we examined the brain activity changes in the prefrontal cortex (PFC). The prefrontal activity was measured in 34 participant pairs of speaker and listener using NIRS. The speaker’s task was to watch an animation and to narrate the story to the listener. Based on the number of gestures produced by each speaker, 34 participant pairs were divided into two groups (high vs. low gesture groups). The results showed that the left prefrontal activity of speakers in the high-gesture group was significantly lower than that of speakers in the low-gesture group, while the bilateral prefrontal activity of listeners did not show any significant differences between the two groups. These findings suggest that production of gestures functions to reduce the cognitive load of memory retrieval and narrative framing in the left PFC.