In her 1995 paper, Nancy Andreasen included two key observations that would grow in significance over the subsequent decades. When she interviewed the subjects afterward, they described their mental activity during the REST state as a kind of effortless shifting back and forth in time. “They think freely about a variety of things,” Andreasen wrote, “especially events of the past few days or future activities of the current or next several days.” Perhaps most intriguing, Andreasen noted that most of the REST activity took place in what are called the association cortices of the brain, the regions of the brain that are most pronounced in Homo sapiens compared with other primates and that are often the last to become fully operational as the human brain develops through adolescence and early adulthood. “Apparently, when the brain/mind thinks in a free and unencumbered fashion,” she wrote, “it uses its most human and complex parts.” - www.nytimes.com