What was going on when I was born?

The Critics' Choices column in The Guide last Sunday referred incorrectly to a Cezanne portrait of Victor Choquet. Although it is cited in the Marlborough Gallery's catalogue as part of a show of 19th- and 20th-century master paintings, the portrait is out on approval and not on exhibit.

A commentary by the Government press agency Tass said today that President Reagan's revised plan for strategic arms reduction was still aimed ''at gaining military superiority and pressing the Soviet Union into unilateral disarmament.'' Tass said Mr. Reagan's decision to revise the proposal for a limit of 850 long-range missiles on each side ''does not in any way affect the essence'' of his original offer, which was rejected by the Russians at talks in Geneva. (At the NATO foreign ministers' meeting in Paris, the United States made public a report aimed at showing that arms control had always been among the highest priorities of American administrations. Page A12.

''The Senate, for the first time, has blown the whistle on outside earned income.

The White House has been taking political soundings on the likely reaction of Republican conservatives should President Reagan reappoint Paul A. Volcker to head the Federal Reserve Board, an aide to the Senate leadership said today. The soundings were regarded as the strongest evidence to date that Mr. Reagan and his advisers were increasingly inclined to ask Mr. Volcker to remain at his post. On behalf of the White House, Senator Paul Laxalt of Nevada, a close friend of the President as well as a political confidant, has been testing the reaction of individual senators to a Volcker reappointment. He has let it be known that he has turned up ''a lot of support'' for Mr. Volcker.

The 10,000 people in Madison Square Garden yesterday were considerably less boisterous than the Garden's usual run of sports or rock concert fans. But they were fans nevertheless - of a corporate variety. More than 10,000 shareholders of the American Telephone and Telegraph Company traveled to the Garden to hear executives of the company talk about what will happen when the communications giant divests itself of its subsidiaries next Jan.1. While the forum was open to any Bell shareholder, the midafternoon session was attended mostly by elderly investors, who made up about 90 percent of the audience.

The White House has been trying to find out how conservative Republicans would react if President Reagan reappointed Paul A. Volcker as head of the Federal Reserve, according to a Senate aide. The effort was seen as the strongest evidence so far that Mr. Reagan is inclined to retain Mr. Volcker. The White House said, however, that no decision will be made before next week. (Page A1.) The S.E.C. proposed extending indefinitely a rule letting companies sell stocks and bonds through shelf registrations. Early opposition to the rule among investment houses appears to have eased, while many corporations are supporting it. (D3.)

ABRIGHT star in the glittering cast of 18th-century America was the polymath Charles Willson Peale (1741-1827). A saddlemaker in his youth, he went on to become a renowned portraitist, for whom George Washington sat no fewer than seven times. A naturalist, he led the first organized scientific expediton in American history. A museologist, he set up the earliest systematic museum of art and natural history in North America. An inventor and developer, he came up with porcelain false teeth and a farm cart based on the principles of the mariner's compass, which would transport milk without spilling it. A devoted husband and father, he survived three wives and sired 17 children, several of whom became artists themselves. The Peale we know best is, of course, the painter, a homespun realist, whose convincing renditions of early American faces - including the members of his own artistic family - reflect the buoyant energy and optimism of a country on its way to success. But the exhibition ''Charles Willson Peale and His World'' at the Metropolitan Museum of Art, Fifth Avenue and 82d Street, through Sept. 4, deals with all of the Peale facets, presenting some 170 objects, including portraits, miniatures, landscapes, drawings, prints and surviving exhibits from Peale's early museum. Surprisingly, it's the first full-dress show ever given to this Renaissance Yankee, whose bustling career embodies that of the young nation.

Members of the Senate, in the wake of an outcry over the outside income they received last year, voted today to limit the amount of money they could earn from speeches and articles. The Senate voted, 51 to 41, to limit members' honorarium income to 30 percent of their $60,662 salaries, or about $18,000. If the provision voted today becomes law, members of the House of Representatives would receive higher salaries than Senators and would be permitted to receive about $3,000 more in outside earned income. ''The Senate, for the first time, has blown the whistle on outside earned income,'' said Senator Henry M. Jackson, Democrat of Washington. ''It's long past due.''

Prime Minister Margaret Thatcher and her Conservative Government scored a crushing victory in Britain's general election on Thursday, winning a majority of about 140 seats over the combined opposition in Parliament. The Tories' sweep was the most far-reaching since the Labor landslide of 1945. Polling barely one vote in four, Labor suffered its worst debacle since 1922; it barely edged out the new Liberal-Social Democratic alliance in the popular vote. The alliance seemed unlikely to win more than 25 seats in the 650-member Parliament, however, because its vote was too evenly spread across the country. It finished second in hundreds of seats; Labor's vote was highly concentrated in its bedrock urban strongholds.

The Chemical New York Corporation, the sixth-largest banking company in the country, named three presidents yesterday, one for each of its major sectors. Walter V. Shipley, Chemical's president since January 1982, said, ''In banking it has not been done this way before, but in industry it is very common that major lines of business are headed by a president.'' Looking to October, when he succeeds Donald Platten as chairman and chief executive officer, Mr. Shipley said he wanted to shift the chain of command to more of a team approach. ''I don't need one No.2 man,'' Mr. Shipley said. ''I need three.''

Gen. Edward C. Meyer, the Army's Chief of Staff, said today that he would oppose sending United States combat forces to El Salvador because Americans would not support them and Salvadorans were not fully committed to defeating leftist insurgents there. The general, in response to a series of questions during a breakfast meeting with reporters, said the United States might have to consider intervention with troops if there was turmoil after the elections in El Salvador later this year. But he said that option should be considered only if there was a clear identification of political purposes, statement of military objectives, and public understanding of the costs in military manpower, weapons, money and time. The general said his views reflected those of the Joint Chiefs of Staff, the military advisers to the President. His comments were the most forthright public expression so far of the reasons senior military officers have opposed sending combat forces to Central America.

The Brazilian Government today announced a series of new austerity measures intended to gain agreement from the International Monetary Fund to proceed with its $4.9 billion program of assistance to Brazil. The steps are being taken to limit the growth of the federal deficit and to slow Brazilian inflation, now at an annual rate of 118 percent. Brazil's failure to meet agreed-upon figures in these two areas led the I.M.F. to hold up a $411 million payment due May 31. Negotiators from the I.M.F. will arrive next week to discuss the matter.