Do you suffer from insomnia?

Does your spouse complain about how much you toss and turn?

Wake up feeling less refreshed than you once did?

Maybe, without even knowing it, you've been fretting over some nagging question from the history of art: Who was better, Raphael or Michelangelo? Did Rembrandt use a hidden camera to get his portraits so lifelike? Did Picasso teach Matisse to toughen up, or did Matisse persuade Picasso to go mellow?

If it's this last question that's causing trouble, you'll want to head for the Museum of Modern Art's temporary home in Queens, where a newly opened show called "Matisse Picasso" is already drawing crowds.

The exhibition surveys the contacts, cross-influences and occasional incompatibilities between these two certified giants of modern art. It gives the definitive answer to the question -- posed and re-posed over the years, in books and lesser shows -- of when and how each master played off the other's work, or deliberately turned his back on it.

Of course, if that's not a question keeping you up nights, this blockbuster exhibition may not do too much for you. If you're already a big fan of just one of these two painters, the MoMA show might even make you lose some sleep.

"Matisse Picasso" was organized by a team of six art historians enlisted by Tate Modern in London, the Musee Picasso and Centre Pompidou in Paris and MoMA in New York, where it's making its final stop. The curators have pulled in a rare spread of more than 130 paintings, sculptures, prints and drawings by their heroes, arranged into 34 pairings or small groups meant to highlight crucial moments in the painters' 50-year artistic tango.

(The catalogue includes 34 related essays, one for each display. The viewing experience gets a big boost from contributions by Elizabeth Cowling, a scholar from Edinburgh, and by Kirk Varnedoe, a former bigwig at MoMA now at Princeton University's Institute of Advanced Study. He's set to deliver the National Gallery's prestigious Mellon Lectures in Washington starting March 30. The other essays mostly range from iffy to plain bad.)

Some of the show's invitations to "compare and contrast" yield genuinely interesting insights, even if they are a touch SAT-ish.

Given what a radical Picasso turned out to be and how viewer-friendly Matisse can now seem, it's easy to forget that things started out the other way around. In his "blue" and "rose" periods of the very early 1900s, when he had just begun to live in Paris, Picasso was not much more than gently moody. Matisse, on the other hand, was already leader of the "fauves" -- the "wild beasts" of modern art's first days.

In an early gallery at MoMA, Picasso's wan, clay-colored picture of a boy leading a horse, from 1906, comes up against Matisse's famously weird and wonky "Luxe I" -- three rubber-jointed naked women doing strange things by the sea -- painted the next year. The pairing shows how far the 26-year-old Spaniard still had to go to catch up with his French counterpart, 12 years his senior.

The two first met around this time, when they were both being collected by Gertrude Stein and family. They might already have seen each other's work in the shows the Steins bought from, or on the Steins' own walls.

By the spring of 1907, Picasso would have had to deal with tough-guy Matisse once again, when the Frenchman's "Blue Nude" made a big splash at the Salon des Independants, an annual showcase of the Parisian avant-garde. We're so used to thinking of Matisse as he turned out later, all cheery color and enchanting line, that his "Blue Nude" still comes as a shock when you encounter it at MoMA. (Once this show is over, Washingtonians will once again be able to hop over to the Baltimore Museum of Art to get a look at it.)

A big-breasted, huge-hipped nude, painted with so much black and blue that she looks almost bruised, is stretched out in a kind of eerie, black-light patch of untamed nature. This is Eve set in a jungle Eden, with no use at all for Adam.

In the terms of this exhibition, which imagines the two artists as determined rivals caught up in an unending psychodrama, Picasso's rejoinder to the "Blue Nude" is his earth-shaking, monumental "Demoiselles d'Avignon," a treasure from MoMA's own collection. The painting started out as something tamer; as this show tells the story, Picasso would have boosted its volume after seeing what Matisse was getting up to.

Where Matisse's lonely nude has the kind of tough beauty that asserts her independence from the desires of her (male) viewers, Picasso's five naked prostitutes, unbeautiful in the extreme, have been hardened by a professional eagerness to please. They stretch their arms, spread their legs, and throw open curtains to make themselves as available as possible. In a further gesture of what was conceived as deliberate uglification, in the final version of the picture he painted over the almost Homeric, Mediterranean, "ox-eyed" faces of two of these women, giving them African-inspired masks.

In 1907, Picasso had only recently come across the art forms of Africa -- Matisse had helped to introduce them to him -- and saw in them a way forward for European art. (Matisse was fascinated by African art, too, although it didn't much affect his painting.) But this promising future didn't lie in spotting a new beauty that could be imported from abroad, as we might see the matter now -- or as Matisse might have imagined his own borrowings from medieval and Persian art. For Picasso, borrowing from African art was about finding a deliberate, "primitive" ugliness that could work as an antidote to "advanced" Europe's addiction to the pretty. It worked. Most viewers found the "Demoiselles" a shocking mess -- which can't have wholly displeased its maker.

Matisse was among those who didn't like the painting, having visited it in Picasso's studio. But even he couldn't escape its influence. His "Bathers With a Turtle," painted the following year on a canvas only slightly smaller than the "Demoiselles," has a toughness that goes beyond even his "Blue Nude." Three naked women, awkwardly proportioned and very coarsely painted, huddle in inexplicable dismay around a tiny turtle painted red. Picasso's attempt to one-up the "Blue Nude" seems to take him in a direction he was already heading, or that came naturally to him; Matisse's trumping of that same work -- or, according to this show, of Picasso's almost-cubist rejoinder to it -- seems to lead in a direction that he couldn't follow very far.

In these early pieces, it's not hard to see the two painters bouncing off each other's art. As both achieve more independent mastery, and fame, their relationship becomes more strained, and the contacts are less easy to make out. In the few cases where we have actual records of the indebtedness of one picture to another, the loan is hardly obvious.

A 1914 Matisse called "Goldfish and Palette" seems to have some Picasso in it. The subject matter is trademark Matisse -- a bowl of goldfish on a stand in front of a balustraded window, with the artist's palette set off to the right. Its colors, however, are less cheery than Matisse's norm, with a broad rectangle of black running down the picture's middle. And there are strange moments where objects' edges dissolve into a cubist haze out of Picasso. But it turns out that the influence runs the other way: Matisse complained that Picasso's important "Harlequin," painted in 1915, had stolen from his picture.

At first, the theft isn't easy to see. Matisse's painting, for all its cubist bits, gives an almost-natural view of the world, via a brushy, painterly surface; "Harlequin," on the other hand, is a product of Picasso's so-called "synthetic" cubism, made up of clean, geometric fields of color that only vaguely come together into credible objects. The theft from "Goldfish and Palette" can be seen, once you really search for it -- an extensive use of black, a composition built around a central rectangle, and a palette in the middle right -- but it hardly seems actionable.

Four decades later, a year after Matisse's death, Picasso set out to pay homage to his erstwhile rival and sometime friend. (As each aged into a venerated art-world silverback, they had found themselves with more and more in common. They wound up living not too far apart in the south of France.) The series of late-cubist pictures that came out of this commemorative moment, titled the "Women of Algiers," take off from a Delacroix that Matisse liked and give a nod to the Mediterranean hedonism that the dead artist had always played around with. But there is no sense that, even in this deliberate act of invocation, Picasso has tried to make his pictures conjure up the dead man's art.

Which brings us to this show's major stumbling block. If known contacts between the two artists don't always show up clearly on the surface of their works, how can anybody hope to pair up pictures that there aren't records for?

Most often, this exhibition matches pictures by deciding that they look a bit the same. A 1912 studio interior by Matisse includes a partial glimpse of his own famous painting called "The Dance," with three figures holding hands and skipping in a circle. The Picasso that hangs by it, from 1925 and about the same size as the Matisse, also centers on three figures dancing with linked hands. Otherwise, the two pictures could hardly be more different: One is a charming, peaceable view into a domestic space decorated with a painted frieze of dancers; the other is an aggressive, peculiar image of three wildly distorted figures imagined in real space, whose dance is closer to a witches' jig than the idyllic saraband seen in the Matisse. To concentrate on the superficial similarities between these two pictures is to risk a profound misunderstanding of what they're all about. They are like the "false friends" that language teachers warn against -- words that sound the same in French and Spanish, say, but have quite different roots and mean wholly different things.

The exhibition's other trick for matching pictures by these artists, according to their subject matter, does even less useful work.

Two pictures of seated women -- Picasso's 1927 "Woman in an Armchair" and Matisse's "Decorative Figure on an Ornamental Background," finished a year or so before -- are presented side by side. All they show is how radically, irreconcilably different these two artists were at this moment in time -- a moment, incidentally, when they were living at opposite ends of France and were barely on speaking terms. To note the gap between their art is hardly news to anyone and is not an observation that will take you very far. (A Picasso portrait doesn't look much like one by Rembrandt, either, or like any by a thousand other artists, but what are we to make of that? A show built around all those famous painters who didn't influence each other would be rather large.) Same problem for the pairing of Matisse's painting called "Interior With a Violin" and Picasso's sheet-metal sculpture of a cubist guitar, or the various still lifes that get placed side by side in this show. There's too much standard subject matter in the Western tradition, as well as time-hallowed arrangements of it, for us to make a fuss about echoes or rhymes that seem to run from one picture to another.

And yet, as this show is constructed, it's impossible to ignore these visual rhymes -- it would be like trying to read a limerick as ordinary speech. I dare anyone to walk through this exhibition without playing an obsessive game of "spot the difference" or "find the similarity," or at least trying to puzzle out what any given work by one master is supposed to say about the other. The selection of works is so premise-driven that the objects risk becoming simple-minded illustrations for the show's argument, rather than free-standing works of art with lots of different kinds of things to say.

This exhibition has pulled in quite a few wonderful works from private or obscure collections. A couple named Tony and Gail Ganz have lent a brilliantly grim, wartime Picasso painting of a tabletop bearing a knife, a coiled sausage and two artichokes, all painted in shades of gray. (In her essay, Cowling sees in it a coiled mess of bowels and two severed hands, which doesn't seem as far-fetched as it sounds. Think of black-and-white news photos of the carnage of war.) An unidentified lender provided Matisse's stunning 1916 "Bowl of Oranges," a simple, symmetrical composition that captures the glass container and its charge of fruit with spectacular economy and force. But, for all their stand-alone quality, Picasso's monochrome still life ends up reading only as a foil for a brightly colored one by Matisse that sits next to it, while Matisse's fruit bowl seems joined at the hip to Picasso's nearby "Pitcher and Apples."

If anything, these artists suffer more from their constant comparison than they gain by it. Matisse is necessarily mostly shown at his toughest, most Picassoid moments: You would barely guess that he was a painter famous for bright, lighthearted hedonism, who said that a painting should be like a comfortable armchair that viewers can settle into. Picasso, meanwhile, tends to look more colorfully Matissean than he might have wanted: Analytic cubism, his most famous style, is barely represented, since Matisse never took much notice of its taciturn monochromes. In a show of works cherry-picked to underline similarities, crucial differences inevitably get played down -- and likeness hardly comes as a surprise.

Of course, this exhibition only claims to tell a single story, about the points of contact between Matisse and Picasso. Fine. But like it or not, it does far more than that: Its blockbuster scale, and all the hype that's grown up around it, inevitably implies that this is the whole and only story there is to tell. It implies that the rich and complex history of these two artists' work, and of modern art in general, can be reduced to a Claymation Battle of the Titans.

Matisse Picasso is at the Museum of Modern Art in Queens until May 19. Call 212-708-9400 or visit www.moma.org.

Giants' steps: Matisse's 1914 "Goldfish and Palette," left, and Picasso's 1915 "Harlequin," above, are among the examples given in "Matisse Picasso," the Museum of Modern Art's at times strained exhibition of the influences of the two artists on each other.Radically, irreconcilably different: The thesis of MoMA's show is undercut by Matisse's 1925-26 "Decorative Figure on an Ornamental Background," left, side by side with Picasso's 1927 "Woman in an Armchair," above.Matisse's 1952 "Acrobats," above, and Picasso's 1930 "Acrobat": The show imagines the two artists as determined rivals caught up in an unending psychodrama.Matisse's 1917-18 painting "Interior With a Violin," above, and Picasso's 1924 sheet metal sculpture "Guitar" are paired in "Matisse Picasso," but any echo between the two can be explained by their both addressing standard subject matter in the Western tradition.