It is a "myth" of U.S. politics that the Kremlin deliberately tests the will of each new occupant of the White House to resist Soviet expansion, an American scholar told a conference of academic specialists here yesterday.

A study of the American-Soviet record since the 1950s shows that "The notion of Soviet 'testing' of new American presidents is simply dead wrong," said George W. Breslauer of the University of California.

The persistence of this belief, he said, "can best be explained by its utility as a legitimizing myth in U.S. politics."

"Indeed," Breslauer told an audience of specialists on eastern Europe, "the opposite proposition has much greater basis in the historical record: that U.S. behavior toward the Soviet Union during presidential transitions was, more often than not, characterized by increased belligerence."

American presidential campaigns, he said, generally stimulate a tougher, more bristling U.S. posture toward the Soviet Union.

Therefore, he maintained, there is "a correlation between the U.S. electoral cycle and changes in U.S. behavior toward the Soviet Union."

On this record, he argued, some of the regular changes in Soviet power and policy "may have to be reinterpreted" as not simply due to internal Soviet requirements, but "as reactions to U.S. moves in the international arena."

That provocative analysis was given to a panel entitled "Soviet Views of the U.S. Presidency" in the second day of the annual convention of the American Association for the Advancement of Slavic Studies at the Capital Hilton Hotel. Breslauer said the cycles of "fundamental turning points" in Soviet power struggles and domestic policy "happen to coincide rather strikingly with the U.S. presidential electoral cycle."

That may be "simple coincidence," he said, but his studies indicate much more than that, he added.

There is "a familiar pattern," he maintained, by which "U.S. belligerence" has "only benefited the Soviet hard-liners." Many hawkish American analysts, however, have long challenged that line of thinking.

The Soviet Union's "American policy" has now been "reduced to a shambles," said another panelist, Franklyn Griffiths of the University of Toronto.

From Soviet perspective," Griffiths said, "the commitment of the Reagan administration to restore the United States to a position of primacy is not regarded as credible. Nor is it regarded as a response to Soviet behavior."

Griffiths sees the Soviet Union as being in a "hold-the-line" posture, awaiting the outcome of the Nov. 2 midterm elections in this country and watching for "the incapacity of the Reagan administration" to be demonstrated, to confront the United States with a need "to return to detente," possibly through the election of a Democratic president in 1984.

But the odds, he said, are on "a greater Soviet policy of militancy and emphasis on Soviet expansionist tendencies in the years ahead."

Griffiths said that in the past, notably in the Nikita S. Khrushchev years, the Soviet Union tried to influence the American electoral process by encouraging what it regarded as presidential candidates "more likely to yield to perceived Soviet needs."

Since 1964, he said, the Soviet leadership has essentially abandoned attempts "to reform the United States," and concentrated instead on efforts to improve Soviet strength and pressure the United States "to behave with greater restraint."

But the leadership overestimated the durability of the American commitment to its concept of detente, Griffiths said, and also U.S. willingness to allow the Soviet Union "to press for unilateral advantage."

It is important to recognize, Griffiths said, that Soviet decision-makers operate with multiple, competing images of the American scene, and "each image puts the pieces of the American puzzle together in different fashion." He identified four competing images of the United States in Soviet literature since 1945, beginning with the Stalinist image of the United States as "a one-party state governed for the monopolists by the Democratic-Republican Party," with the president "as the puppet of the financial oligarchy."

The subsequent, competing Soviet images of the United States show considerably increased knowledge about the American system, the role of the president and the political parties, Griffiths said, but these images are still short of American realities.

Another panelist, Lawrence T. Caldwell of the Central Intelligence Agency, said Soviet sophistication about the United States "has increased enormously" since the 1950s.