應用腦訊號與臉部表情影像於華人與俄羅斯人之非語言溝通方式研究(2/3)

Synchronous neural patterns can occur when two brains are coupled through a physical stimulus, such as light, sound, or pressure. Inter-brain synchrony can be caused by various factors, such as cooperation in task engagement, social interaction, emotional contagion, neural mirroring, or shared attention and perception. This study aims to measure the brain synchrony between individuals with different linguistic backgrounds by having them play nonverbal facial communication games. Two eight-channel EEG systems were used to simultaneously measure two remotely situated participants with different language backgrounds in playing the nonverbal facial communication game designed in this study. Six groups (twelve participants; two participants per group) located in two different countries were recruited to participate in an Easy game and a Difficult communication game. The participants' Electroencephalography (EEG) signals were analyzed using a two-layer empirical mode decomposition (EMD) to decompose the measured EEG signals into frequency-modulated intrinsic mode functions (IMFFMs) and amplitude-modulated intrinsic mode functions (IMFAMs). The phase-locking values (PLVs) between the Easy-condition and Difficult-condition in IMFFMs and IMFAMs were calculated and compared. As the number of execution time increased, the PLVs of the IMFFMs in the frontal cortex was significantly greater under the Difficult-condition in both alpha and beta bands, compared to the Easy-condition (p<0.01). Further investigating the IMFAMs, the AM modulation of alpha-band EEG showed a significant phase synchronization around 0.76 ± 0.13Hz in playing Difficult game (p<0.01), and the AM modulation of beta-band EEG showed a significant phase synchronization around 1.14 ± 0.15 Hz under the Difficult-game condition. This study demonstrated the inter-scale coupling of brain signals when the participants were engaged in a more challenging nonverbal cooperative game.