Ever Wonder How Some People Remember Every Day of Their Life?

Could you say what day of the week Jan. 1, 1984, fell on? How about the date Princess Diana and Prince Charles were married or the day the first Star Wars opened in theaters? Could you then elaborate on personal details of what happened to you on that day?

These are just a few questions researchers are asking subjects being studied for a "highly superior autobiographical memory," according to NPR. Most people can only answer questions such as these with 15 percent accuracy, University of California-Irvine researcher James McGaugh told NPR. Those with highly superior autobiographical memory (HSAM) on the other hand can get 55 percent of them right.

NPR describes Bob Petrella as one of those with an extraordinary memory. In addition to identifying the date of a news event or the notable event that occurred on a specific date, Petrella, who is 62 years old, was able to tell researchers Jan. 1, 1984, fell on a Sunday, which was the day the Steelers, his favorite team, lost to the Raiders, 38-10.

McGaugh said the 11 people being studied are not considered to have photographic memories, and when it comes to everyday memory tasks, they score relatively normal. McGaugh and colleagues recently published a study of these people in the journal Neurobiology of Learning and Memory:

Results indicated that HSAM participants performed significantly better at recalling public as well as personal autobiographical events as well as the days and dates on which these events occurred. However, their performance was comparable to age- and sex-matched controls on most standard laboratory memory tests. Neuroanatomical results identified nine structures as being morphologically different from those of control participants. The study of HSAM may provide new insights into the neurobiology of autobiographical memory.

A new finding the researchers were able to link to those with HSAM was obsessive-compulsive disorder, which researchers believes will help them in further memory studies.

"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 told NPR about Petrella.

NPR added that MRI scans of these individuals' brains found the area linked with OCD seems to be larger.

Scientists plan to continue studying these 11 participants and nine specific regions of their brains that appear different compared to those in the control group to better understand memory as a whole and why theirs seem to be so good.

Listen to NPR's full report on Morning Edition: