What was going on when I was born?

The art gallery at the Asia Society, 725 Park Avenue, at 70th Street, boasts ''Emaki: Narrative Scrolls From Japan'' (through Nov. 6), a small but incomparable group of lively ''picture scrolls,'' from medieval times to the 20th century, which regale us with dramatic scenes of adventure, romance, battle, history, biography and Buddhism. And at the Japan House Gallery, 333 East 47th Street, there is ''Autumn Grasses and Water: Motifs in Japanese Art'' (through Nov. 13), a gathering of 50 elegant, sumptuous things from the 13th to the 19th centuries - screens, lacquerware, textiles and porcelains adorned with classical Japanese emblems of nature - mostly borrowed from the Suntory Museum in Tokyo, which organized the show in conjunction with the Japan Society. One of the key differences between Japanese and Western art is the strong pictorial tradition developed by Western painters since the Renaissance, based on a structured composition depicting the figure and other objects in a unified space. ''Decoration'' - i.e., design that lacks this pictorial structure - is considered secondary, and in Western culture the ''fine'' arts thus have it over the applied, or ''decorative'' arts. But no such distinction occurs in Japanese art, where the decorative and the pictorial can even coexist in the same object. For one thing, the Renaissance concept of pictorial space never invaded Japanese art, and for another - as Masakazu Yamazaki, a Japanese playwright and critic, points out in in essay for the splendid ''Autumn Grasses'' catalogue - the Japanese have always viewed artmaking as a highly social activity.

President Ferdinand E. Marcos said today that he would be compelled to order ''extreme measures'' if there were any resumption of the anti-Government rioting of Wednesday night and early today. The statement, delivered over national television, was taken as a warning that he would reimpose martial law, under which he ruled from 1972 to 1981. Mr. Marcos said his Government held ''the opposition and its leaders responsible for the unfortunate incidents last night and early this morning.'' According to the police, the clashes between security forces and demonstrators left 11 dead and about 200 wounded.

The Soviet Union has rejected an American appeal that it use its influence to restrain Syrian military involvement in the fighting in Lebanon and has blamed the United States for the trouble there, Administration officials said today. The officials disclosed the substance of a secret diplomatic exchange with Moscow this month to underscore their frustration in trying to bring about a cease-fire. A senior Administration official said this afternoon that ''there is a view within the United States Government that one of the fallouts from the Korean airliner incident has been a more aggressive policy by the Russians in the Middle East.'' The official added, ''The Russians seem to think that an exacerbation of tensions in the Middle East would work to their benefit.''

A new book's conclusions that Julius Rosenberg was indeed a Soviet spy whose execution served the purposes of the American Government and the Communist Party has revived an emotional debate about his guilt and the role of his wife, Ethel. The conclusions of the book, ''The Rosenberg File,'' are by no means new. But in a controversy that has thrived for more than three decades, the book's credibility has been enhanced on two counts. Its authors said they began their research believing Mr. Rosenberg and his wife were not guilty, and the authors combine personal interviews with corroborating evidence from Government files, much of which had previously been released but never assembled. But not everyone is convinced. Those who insist the Rosenbergs were not guilty - not guilty, at least, of the formal espionage conspiracy charges and of stealing a key secret to the atomic bomb - still question the credibility of the witnesses for the prosecution.

Markets Stock prices registered a strong advance, with the Dow Jones industrial average closing at a new high for the second time this week. The Dow rose 14.23 points, to 1,257.52, which was 8.33 points higher than its record Tuesday. Analysts cited a late credit market rally and Wednesday's favorable short-interest report. (Page D1.) The auction of $3.5 billion of 20-year Treasury bonds attracted heavy institutional buying. Shortly afterward, prices rose almost a point. (D7.) Assets of money market mutual funds climbed $389 million, to $164.55 billion, in the week ended Wednesday. (D2.)

THE 21st New York Film Festival, which opens this evening, has a rich mix of 32 features in 26 programs from 16 countries and departs from its predecessors in three major areas. The 17-day gala brings to Lincoln Center more directors than any previous festival, 16, more American films than ever, 11, and a movie that generated the sharpest critical split in the selection panel in memory. The five-member panel of experts began using a 1-to-5 rating system about six years ago, according to Richard Roud, the festival's exuberant director and one of its founders. A 1 vote, he said in his basement office at Lincoln Center the other day, connotes, ''I hate this dreadful film, and I'll hate the rest of you if you accept it.'' A 2 vote, he continued, indicates ''I don't like it, but if the rest of you like it, I won't be angry.'' A 3 signifies ''Yes.'' A 4 concludes ''It must be in the festival.'' And a 5? ''It's a masterpiece!''

Under this heading, The Times amplifies articles or rectifies what the editors consider significant lapses of fairness, balance or perspective. Corrections, also on this page, continue to deal with factual errors.

French jet fighters attacked anti-Government gun batteries behind Syrian lines in mountains east of Beirut today, shortly after a barrage of rockets rained down on French and Italian troops in the capital. The air attack, flown by eight Super Etendard planes from the carrier Foch, marked the first time the French have become directly embroiled in fighting with the Syrian-backed Druse militiamen, Palestinian guerrillas and Lebanese leftists. It was also the first time that any of the American, French, Italian or British contingents of the international force here have introduced fighter planes into the conflict. 6 French Troops Wounded A French Embassy spokesman said the fighters ''retaliated against sources of fire that had inflicted damage on French forces in Beirut in the past few days.'' Today's rocket barrage landed in southeastern suburbs of the capital.

TO connoisseurs of street fairs New York City, this weekend will be something of a smorgasbord. On Sunday, 13 blocks of Columbus Avenue will be lined with displays of the Upper West Side's crafts and cuisines, 52d Street will play host to jazz bands, folk musicians and flamenco dancers, and Atlantic Avenue in Brooklyn will offer 12 blocks of antiques, clowns, floats and food. Tomorrow at noon on Fifth Avenue, 7,000 German-Americans are expected to march north from 61st Street in the Steuben Day Parade, which is scheduled to end with beer and wursts at Second Avenue and 86th Street. At the same time, celebrants of a Hindu festival will be marching south from 59th Street, pulling 50-foot floats adorned with flower garlands and multicolored mystical paintings to Washington Square Park. There, the organizers say, they will provide a free vegetarian feast for 10,000 people.

The Sports of The Times column Tuesday incorrectly described Buddy Young's standing among black football players. Numerous all-America teams are selected each year by various organizations, but several black players in addition to Fritz Pollard are regarded as having preceded Mr. Young as all-Americans.

The stock market, propelled by a late rally in the credit markets and a favorable short interest report, made a strong advance yesterday, with the Dow Jones industrial average closing at a new high for the second time this week. At the end of trading, the 30 prominent issues that make up the average were up 14.23 points, to 1,257.52. On Tuesday, the indicator closed at a record 1,249.19 by posting an advance of 15.25 points. The two other major market indexes, which are much more broadly based than the Dow, failed to post new highs although they scored good gains. The New York Stock Exchange's composite index of 1,500 common stocks rose 0.74, to 98.20, and Standard & Poor's index of 500 stocks gained 1.35, to 169.76.

The Securities and Exchange Commission today reduced the amount of information about management compensation that companies must disclose. The new rule is effective immediately. By a vote of 5 to 0, the commission decided that publicly held corporations must continue to report the cash compensation of senior officers but may withhold details of such perquisites as the use of company planes, cars, apartments or club memberships.