History of a thought : introspection-based determinants and neural correlates of spontaneous thought

Spontaneous thought and mind wandering engender approximately 30% of the thoughts\ud one experiences daily, but little research has elucidated the patterns underlying the\ud determinants of spontaneous thought. While performing a concentration exercise (9 min)\ud requiring one to focus on one???s breathing, participants observed spontaneous thoughts\ud and counted the number of cognitions/percepts (???links???) that they believed led to each\ud spontaneous thought. In three studies using this paradigm, participants reported few links\ud (Ms < 2 links) per thought (Ms < 12 thoughts). Participants reported that roughly half of\ud the thoughts were caused by the current environment (Studies 2 and 3). Study 4 expanded\ud on this observation and examined the neural (EEG) correlates of spontaneous thoughts\ud attributed to environmental stimuli or stimulus-independent cognitions. The findings\ud from these studies are consistent with current theorizing about the many constraints\ud (including environmental constraints) on conscious thought. More generally, they begin\ud to illustrate the dynamic and causal nature of thoughts comprising the stream of\ud consciousness