Brain waves yield echoes of the past

New Scientist : Even when at rest, the human brain continues to be active. Such brain activity may echo previous ideas and experiences, say Rafael Malach (Weizmann Institute of Science in Israel) and colleagues. In their paper published in the Journal of Neuroscience, the researchers describe their comparison of MRI scans taken of 20 different subjects before, during, and after a period of intense cognitive activity. With computer software, the researchers analyzed the activity patterns and found that those observed later, when the brain was resting, mirrored those observed when the brain was concentrating on the task. Although such brain imaging experiments are still in the very early stages of development, Malach says he hopes to one day be able to directly correlate brain waves with particular experiences and thus be able to determine a person’s recent past by studying his or her current brain activity.