Amnestic Syndromes: The Play's The Thing ...
January 23, 2007
Amnesiacs May Be Cut Off From Past and Future Alike
By BENEDICT CAREY
The New York Times
In the movies amnesia is bizarre, and thrilling. The star is usually a former assassin or government agent whose future depends on retrieving the bloody, jigsaw fragments that restore identity and explain the past.
Yet in the real world, people with amnesia live in a mental universe at least as strange as fiction: new research suggests that they are marooned in the present, as helpless at imagining future experiences as they are at retrieving old ones.
The new study, reported last week in The Proceedings of the National Academy of Sciences, is the first rigorous test of how brain-injured people with amnesia mentally inhabit imaginary scenes. The results suggest that to the brain, remembered experience and imagined experience are reflections from the same mirror, rich inner worlds animated by almost identical neural networks.
The findings provide a glimpse into what it might mean to truly live in the moment. And they feed a continuing debate about memory. Some researchers say that the brain region central to forming new memories — the hippocampus, a sliver of tissue deep in the brain where the day’s memories are registered — is not necessary for retrieving those experiences, once they have been consolidated elsewhere in the brain.
Others, including the authors of the new study, contend that the hippocampus in fact provides the stage on which inner mental dramas are set. Without its help only the props remain — loose facts, people’s names, snippets from favorite songs: the players without the play.
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