Imaging pinpoints brain regions that 'see the future'
Human memory, the ability to recall vivid mental images of past experiences, has been studied extensively for more than a hundred years. But until recently, there's been surprisingly little research into cognitive processes underlying another form of mental time travel - the ability to clearly imagine or "see" oneself participating in a future event.
Now, researchers from Washington University in St. Louis have used advanced brain imaging techniques to show that remembering the past and envisioning the future may go hand-in-hand, with each process sparking strikingly similar patterns of activity within precisely the same broad network of brain regions.
"In our daily lives, we probably spend more time envisioning what we're going to do tomorrow or later on in the day than we do remembering, but not much is known about how we go about forming these mental images of the future," says Karl Szpunar, lead author of the study and a psychology doctoral student in Arts & Sciences at Washington University.
"Our findings provide compelling support for the idea that memory and future thought are highly interrelated and help explain why future thought may be impossible without memories."
Scheduled for advance online publication Jan. 1 in Proceedings of the National Academy of Sciences, the study sheds new light on how the human mind relies on the vivid recollection of past experiences to prepare itself for future challenges, suggesting that envisioning the future may be a critical prerequisite for many higher-level planning processes.
Other study co-authors are Jason M. Watson, a Washington University doctoral graduate now assistant professor of psychology at the University of Utah; and Kathleen McDermott, an associate professor of psychology in Arts & Sciences and of radiology in the School of Medicine at Washington University.
McDermott, principal investigator for the University's Memory and Cognition Lab, where the research is based, suggests that the findings are notable for two reasons.
First, the study clearly demonstrates that the neural network underlying future thought is not isolated in the brain's frontal cortex, as some have speculated. Although the frontal lobes play a well-documented role in carrying out future-oriented executive operations, such as anticipation, planning and monitoring, the spark for these activities may well be the very process of envisioning oneself in a specific future event, an activity based within and reliant upon the same neurally distributed network used to retrieve autobiographical memories.
Second, within this neural network, patterns of activity suggest that the visual and spatial context for our imagined future often is pieced together using our past experiences, including memories of specific body movements and visual perspective changes