WASHINGTON - The year 1901 was a pivotal moment for Pablo Picasso to experiment and find his own unique style. At just 19 years old, he was living in Paris, dirt poor and painting furiously. It wasn't unusual for him to take one canvas and reuse it to paint a fresh idea.

Now scientists and art experts are revealing they've found a hidden painting beneath the surface of one of Picasso's first masterpieces, "The Blue Room." Using advances in infrared technology, they have uncovered a hidden portrait of a bow-tied man with his face resting on his hand.

Now the question that conservators at The Phillips Collection in Washington hope to answer is simply: Who is he?

It's a mystery that's fueling new research about the painting. "The Blue Room" was made early in Picasso's career while he was working in Paris, at the start of his distinctive blue period of melancholy subjects.

Curators and conservators revealed the discovery of the portrait for the first time to The Associated Press last week.

Something's Up With The Brushstrokes

"When he had an idea, you know, he just had to get it down and realize it," Phillips curator Susan Behrends Frank told the AP, describing how Picasso had hurriedly painted "The Blue Room" over another complete picture. "He could not afford to acquire new canvases every time he had an idea that he wanted to pursue. He worked sometimes on cardboard because canvas was so much more expensive."

Experts long suspected there might be something under the surface of "The Blue Room," which has been part of The Phillips Collection since 1927. Brushstrokes on the piece clearly don't match the composition that depicts a woman bathing in Picasso's studio.

A conservator noted the odd brushstrokes in a 1954 letter, but it wasn't until the 1990s that an X-ray of the painting first revealed a fuzzy image of something under the picture. It wasn't clear, though, that it was a portrait.

In 2008, improved infrared technology revealed for the first time a man's bearded face resting on his hand with three rings on his fingers. He's dressed in a jacket and bow tie, painted in a vertical composition.

"It's really one of those moments that really makes what you do special," said Patricia Favero. Favero is the conservator at The Phillips Collection who pieced together the best infrared image yet of the man's face.

"The second reaction was, 'Well, who is it?' We're still working on answering that question."

Identity Of The Mystery Man

Scholars have ruled out the possibility that it was a self-portrait. One possible figure is the Paris art dealer Ambroise Vollard, who hosted Picasso's first show in 1901. But there's no documentation and there are no clues left on the canvas, so the research continues.

Over the past five years, experts from The Phillips Collection, National Gallery of Art, Cornell University and Delaware's Winterthur Museum have developed a clearer image of the mystery picture under the surface. A technical study confirmed the hidden portrait is a work the Spanish artist likely painted just before "The Blue Room," curators said.

Since the portrait was discovered, conservators have been using other technology to scan the painting for further clues. Favero has been collaborating with other experts to scan the painting with imaging technology and X-ray mapping to try to identify and map the colors of the hidden painting. They would like to recreate a digital image approximating the colors Picasso used.

Curators are planning the first exhibit focused on "The Blue Room" as a seminal work in Picasso's career for 2017. It will examine the revelation of the man's portrait beneath the painting, as well as other Picasso works and his engagement with other artists.

Picasso's Habit Of Painting Over A Painting

For now, "The Blue Room" is part of a tour to South Korea through early 2015 as the research continues.

Hidden pictures have been found under other important Picasso paintings. A technical study of "La Vie" at the Cleveland Museum of Art revealed Picasso significantly reworked the painting's composition. And conservators found a portrait of a mustached man beneath Picasso's painting "Woman Ironing" at the Guggenheim Museum in Manhattan.

Dorothy Kosinski, the director of The Phillips Collection, said new knowledge about Picasso and his process can be discovered through the high-tech collaboration among museums.

"Our audiences are hungry for this. It's kind of detective work. It's giving them a doorway of access that I think enriches, maybe adds mystery, while allowing them to be part of a piecing together of a puzzle," she said. "The more we can understand, the greater our appreciation is of its significance in Picasso's life."