either ‘evoked’ or ‘induced’. Phase-aligned ERO signals (during the trials of cognitive events) are called ‘evoked’ or ‘phase-locked’ oscillations, while the (remaining) signals that become ‘out-of-phase’ across trials are termed ‘induced’ or ‘non-phase-locked’ oscillations [90]. The combination of both evoked and induced oscillatory power has been referred to as ‘total’ power [78]. Further, specific frequency bands within oscillatory responses have been attributed to underlie various cognitive processes [91-95], although the interpretation is often task-specific. For example, delta oscillations are thought to mediate signal detection and decision making (e.g., [91,96,97], while theta frequencies are linked with different cognitive processes, such as conscious awareness, recognition memory, episodic retrieval, and frontal inhibitory control [83,92,94,96,98,99]. The slow alpha rhythm (8-10 Hz) has been reported to modulate as a function of attentional demands [100-102], and fast alpha activity (10-12 Hz) has been shown to mediate semantic memory processes as well as stimulus-related aspects [92,101,103,104]. Further, it has been shown that oscillatory gamma responses are involved in visual perception, cognitive integrative function such as “binding,” and frontal input during sensory processing (top-down processing) [93,96,105-107]. Furthermore, these event-related oscillatory rhythms have been shown to mediate neural communication; higher frequency oscillations are involved in more localized neural networks,
