Abstract: Mind-wandering is involuntary conscious experience arising internally, and it’s a significant part of “stream of consciousness”. The phenomenon of mind-wandering suggests the significance of non-perceptual consciousness in human consciousness system, and the significance of ongoing unconscious processing for individual survival. The research about mind-wandering is becoming the live topic in psychology and cognitive neuroscience. After reviewing the studies about the content of mind-wandering, its relation with emotion and its neural correlates, we discussed the possible mechanism of mind-wandering and its adaptive function. At the end of the paper, we summarised the deficiency of the existing studies, such as the ambiguity in the definition of mind-wandering and the methodological limitations, and the future study trends was developed.

Key words: mind-wandering, non-perceptual consciousness, emotion, default network, self consciousness