“…The mean K represents the network density, in which the network connections are sparse when the average node degree is small. Meanwhile, functional near‐infrared spectroscopy (fNIRS) is a noninvasive and affordable neuroimaging technique (Ehlis, Schneider, Dresler, & Fallgatter, 2014; Ferrari & Quaresima, 2012; Vanderwert & Nelson, 2014), which utilize the near‐infrared light (wavelengths between 680–950 nm) to inspect the brain activation by measuring the concentration changes of oxygenated hemoglobin (HbO) and deoxygenated hemoglobin (HbR) (Ferrari & Quaresima, 2012; Jobsis, 1977; Villringer & Chance, 1997). fNIRS studies have been conducted to reveal the neural mechanisms underlying various cognitive tasks (He, Wang, Li, & Yuan, 2017; Lu, Wang, Zhang, Chen, & Yuan, 2017; Wang, Lu, Hu, Zhang, & Yuan, 2018).…”