In January, researchers in the United Kingdom reported that five people with amnesia caused by damage to the hippocampus, a crucial memory center in the brain, were less adept than healthy volunteers at envisioning hypothetical situations such as a day at the beach or a shopping trip. Whereas healthy subjects described such imagined events vividly, the amnesic patients could muster only a few loosely connected details, suggesting that their hippocampal damage had impaired imagination as well as memory.
In April, a brain-imaging study with healthy young volunteers found that recalling past life experiences and imagining future experiences activated a similar network of brain regions, including the hippocampus. Even studies with rats suggested that the hippocampus may have a role in envisioning the future: One team reported in November that when a rat faces a fork in a familiar maze, neurons in the hippocampus that encode specific locations fire in sequence as if the rat were weighing its options by mentally running down one path and then the other.
On the basis of such findings, some researchers propose that the brain’s memory systems may splice together remembered fragments of past events to construct possible futures. The idea is far from proven, but if future experiments bear it out, memory may indeed turn out to be the mother of imagination.