February 05, 2008

Brain Injury May Not Erase Long-Term Memory

TUESDAY, Feb. 5 (HealthDay News) A new interviewing technique has drawn out extensive details hidden in the long-term memories of people with memory impairment, U.S. researchers say.

There's ongoing debate about whether long-term memory is always dependent on a brain region called the medial temporal lobe, which contains the memory-processing center called the hippocampus.

This study, conducted by a team at the University of California, San Diego School of Medicine, supports the theory that very long-term or remote memory remains intact, even after damage to this lobe.

Larry R. Squire, a professor of psychiatry, neurosciences and psychology, led the study, which used a new method called the Autobiographic Interview to examine the ability of five people with selective brain damage to recall events from their past. Three patients had limited damage to the hippocampus, and two had large medial temporal lobe lesions.

The researchers used extensive interviewing to get patients to provide 50 or more details of one memory from each of five periods in their lives: childhood, teen years, early adulthood, middle age and the year immediately before testing.

The results showed "that autobiographical recollection was impaired in patients with medial temporal damage when memories were drawn from the recent past, but fully intact when memories came from the remote past," Squire said.

The study appears in this week's issue of the Proceedings of the National Academy of Sciences.

More information

The MedlinePlus Medical Encyclopedia has more about memory loss.

-- Robert Preidt
SOURCE: University of California, San Diego, news release, Feb. 4, 2008
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