Brain areas interact with each other to perform individual roles and continuously process information. These numerous connected brain regions form a complex and integrated network that communicates with each other linked brain areas (van den Heuvel and Hulshoff Pol, 2010). Thus, for the brain to function properly, it requires a balance between the activities of individual brain areas and the integrated activities of neural networks (Friston, 2001; Le Van Quyen, 2003). Connections of brain areas through the synchronization of neural oscillations generated in several areas are necessary to integrate this information (Buzsáki and Draguhn, 2004). In particular, it has been suggested that synchronization between more distant areas, even more than that between closer areas, is an important mechanism for communication and integrating information among brain areas (Coullaut-Valera et al., 2014). For example, a study that measured brain activity while monkeys were performing a visual memory task reported that the link between the inferior temporal cortex and the prefrontal cortex was important for recalling stored information and forming new memories (Fuster, 1997). This result indicates that activation of neural networks covering
