A Southern California man employed in the entertainment business is the fourth person verified by scientists to have an ultra-rare memory gift: He recalls in detail most days of his life, as well as the day and date of key public events, says Larry Cahill, who co-leads a project on people with super-memory.

The name of the latest "bona fide" won't be released by scientists because he's a research subject, but he is free to identify himself.

Meanwhile, MRI scans on Jill Price, 43, the Los Angeles religious school administrator who in 2006 was the first person confirmed to have such an ability, reveal two abnormally large areas in her brain.

That discovery could lead to breakthroughs on how memories are formed and kept, says Cahill, a neuroscientist at the University of California-Irvine. Price went public last year with the publication of her book, The Woman Who Can't Forget.

The two magnified areas in Price's brain are the caudate nuclei - typically used for memory when forming automatic habits - and a part of the temporal lobe that stores facts, dates and events, Cahill told USA TODAY.

These two areas of the brain may be working together, in a way unknown before, to make detailed recall of every day as automatic as remembering to brush your teeth in the morning or put on a seat belt, the research team speculates.

When Price first met the team eight years ago, "it seemed more of a scientific curiosity," Cahill says. "Now what we're looking at is a new chapter in the book on memories and the brain."

Hundreds of potential subjects have contacted the researchers, offering to be screened, he says. "Two or three look like the real McCoy" based on phone tests.

In addition to Price and the latest subject, the team also has verified the gift in Brad Williams of La Crosse, Wis., and Rick Baron of suburban Cleveland.

Unlike Price, the three men are left-handed, and they're not troubled by their rare ability, Cahill says. Price feels tormented by her onslaught of memories. She sees daily life in a kind of "split-screen," with present-day events, songs, smells, even TV programs cuing her back to detailed memories that she can't squelch. Gender differences in the brain could account for the differences, Cahill believes.

The larger areas in Price's brain almost certainly explain her rare gift, which was probably present at birth, says Brian Levine, a memory expert with Rotman Research Institute-Baycrest Centre at the University of Toronto.

Scientists now need to find out how the two large brain areas are connected so they can work together. "This may be a key piece of the puzzle as to how memory works, and that can be used in future research to help people with memory disorders," Levine says.