Researchers are using MRI scans to learn more about the brains of people with extraordinary memory.
Six years ago,
we told you
about a woman, identified as A.J., who could remember the details of
nearly every day of her life. At the time, researchers thought she was
unique. But since then, a handful of such individuals have been
identified. And now, researchers are trying to understand how their
extraordinary memories work.
Bob
Petrella, 62, of Los Angeles had to go through a lot of memory testing
to qualify as someone with superior autobiographical memory. First,
there were lots of questions about news events from the past several
decades, like the O.J. Simpson car chase.
Petrella scored 55 percent correct on the news events, according to a
paper published in July in the journal
Neurobiology of Learning and Memory. (Most people get 15 percent.) Then he was quizzed about his own life.
"They
asked, 'What day of the week was Jan. 1, 1984?' — which was a Sunday,"
Petrella recalls. "And the Steelers, my favorite team, lost to the
Raiders that day, 38-10."
Petrella is one of 11 individuals who have now been extensively studied by memory researcher
James McGaugh at the University of California, Irvine. The testing has shown that Petrella and the others like him don't use memory tricks.
They don't have photographic memories. They're not savants. Other than their remarkable memories, they're normal, says McGaugh.
"They're reasonably successful in what they do. There is a professional violinist; there is
Marilu Henner, who is a successful actress ... and so on," McGaugh says.
Surprisingly,
Petrella and the group didn't do any better than you or I would on most
standard memory tests — like repeating back lists of words, or a string
of numbers. It's their autobiographical memory that's exceptional.
Other types of memory are pretty much normal.
"People
like us, we forget normal things. Like, I forgot where I parked my car a
couple of months ago coming out of a theater. Or I forget where I left
my keys," he says.
The researchers have identified another surprising set of behaviors that these individuals share.
Here
are a few questions from the preliminary screening for people with
extraordinary memories. Subjects are given either a date and asked to
give the event, or an event and asked to give the date.
- May 25, 1977. Answer: Star Wars opened, a Wednesday.
- Death of Anna Nicole Smith. Answer: Thursday, Feb. 8, 2007.
- July 29, 1981. Answer: Princess Diana and Prince Charles were married, a Wednesday.
"Most, if not all of them, have some
obsessive-compulsive tendencies," says Petrella. "They tend to save a
lot of objects. They tend to have some repetitive habits. They tend to
store things."
Take Petrella, for example.
"He's
germ-avoidant. If he drops his keys, he has to wash them. He can't wear
shoes that have shoestrings, because shoestrings touch the ground,"
McGaugh says.
But the obsessive
tendencies don't seem to interfere with daily living, McGaugh says. It's
a tantalizing clue, especially when coupled with the MRI findings that a
brain area known to be involved in
obsessive-compulsive disorder, or OCD, is larger than normal in these folks.
This
brain area, called the caudate, may be related to having the constant,
repetitive and precise replay of past events. The brain scans also
revealed other differences in brain structure.
"What we've identified are nine regions of the brains of these subjects that differ from those of control subjects," he said.
Many
of these regions are involved in memory encoding and retrieval. McGaugh
hopes further research on these individuals will reveal how their
phenomenal memories work, and perhaps how ordinary memory works as well.
Hate
Mondays? Think that people have bad moods on Mondays more than any day
of the week?
