Imagine former President Bill Clinton celebrating his birthday in the Oval Office. Then envision your next birthday party and recall your previous one. Do this lying in a functional magnetic resonance imaging (fMRI) machine and you will have an idea of what researchers instructed 12 female and nine male subjects, all right-handed, to do so they could attempt to determine the regions of the brain exclusively used when humans envision specific future events.
Neuroscientists Karl Szpunar, Jason Watson and Kathleen McDermott measured the brain activity of subjects as they performed these and similar tasks. Because people in scanners tend to consider various aspects of their own lives, the researchers explicitly asked subjects to also mull memories of past events. But simply comparing predictions with memories could end up canceling out brain regions employed in both conditions, so researchers added a third: imagining Bill Clinton in the same or similar scenarios. For example, a subject might be asked to recall a previously attended barbecue, imagine a future one as well as picture Clinton at such a cookout.
By canceling out regions that were similarly employed in all three testing scenarios--such as the parts of the brain associated with breathing, seeing, and so on--the neuroscientists uncovered those parts of the brain selectively employed when performing these jobs. Eight different regions displayed extra activity--in other words benefited from increased blood flow--when dealing with imagining the future, including Brodmann's area, the medial posterior parietal cortex and the posterior cerebellum, among others. An additional 15 regions played a role in either remembering the past or imagining the future, including those previously identified as important for remembering locations visited in the past.
This seems to suggest that "to effectively generate a plausible image of the future, subjects reactivate images (e.g., visual-spatial context)," the researchers write in a paper published online January 1 in Proceedings of the National Academy of Sciences USA. "Postexperiment questionnaires indicate that while envisioning the future, subjects tended to place those images in the context of familiar places (e.g., home, school) and familiar people (e.g., friends)." In other words, to imagine the future, we remember the past and put our projection in that context.
Because none of the subjects had actual experience with Bill Clinton, imagining him did not benefit from such memories, though many could picture the environs in which he would find himself. As one subject put it: "I see Bill Clinton at a party in the White House, alongside several faceless senators." These faceless senators, and the subjects who imagined them, however, have given at least a preliminary indication of where future research into the brain regions associated with picturing what will come might delve.