As the Kremlin maneuvers toward the first summit between a Soviet leader and an American president in six years, hopes in the West are inevitably rising that, despite the cold recent past, better relations may yet take shape after Geneva.

But to gauge Moscow's capacity to improve the atmosphere, the West must inevitably turn its attention to the most painfully dramatic evidence of the communist superpower's inner nature -- its brutal punishment of those who dare to "think differently," as dissidents of all persuasions are commonly described in the U.S.S.R.

Nothing so appalls the community of nations as the assiduous Soviet punishment of human-rights activists, blue-collar reformers, religious proselytizers, nationalists, writers, philosophers, hopeful Jewish ,emgr,es, and the many others who have the courage to assert their views or gather information in contravention of the regime's bizarre claim that "total unanimity of view" exists between party and people.

The victims of Soviet religious, racial and political repression are hidden in places far from our view: the labor camps of the Perm region in the Urals; crude exile villages deep in Siberia and the Soviet Far East; sinister "Special Hospitals for the Criminally Insane" which sit behind high walls in such cities as Dnepropetrovsk, Alma Ata and Moscow.

But even those remote places are no longer far enough away to escape notice, condemnation and alarm. The new leadership of Mikhail Gorbachev recognizes this, as shown by its absurd and bitter new propaganda attempt to paint the United States as a repressive police state.

There is, however, a detailed record of Moscow's grim reliance on abuse to silence critics and intimidate activists. A torrent of documented accusations has been made against the Soviet state by those who survived its repressions and are now safe in the West and by brave relatives and friends of prisoners of conscience still in the U.S.S.R.

Rather than avoiding the truth, the Kremlin could quickly improve matters prior to -- and after -- the Geneva summit by releasing scores of prisoners of conscience.

The most prominent case at the moment is that of Yelena G. Bonner, wife of exiled Soviet Nobel Peace laureate Andrei Sakharov. Her family in the United States anxiously awaits word that she will be allowed to cross the Soviet Union's closed borders to receive medical treatment for her failing eyesight. Sakharov risked his own increasingly frail health by engaging in a hunger strike some months ago to force the authorities to allow her out for help. There are hundreds of additional cases that cry out for common decency, for a merciful gesture from the Kremlin.

Among these is that of Anatoli Koryagin, a Soviet psychiatrist imprisoned in a strict-regime labor camp. He was convicted of slandering the Soviet state: he declared perfectly sane more than a dozen persons who had been treated for mental illness in state psychiatric wards because of their dissenting political views. Dr. Koryagin's health is failing, a result of beatings by camp guards and his own hunger strikes to protest illegal prison procedures and conditions. Amnesty International and the International Association on the Political Use of Psychiatry in London have repeatedly sought assurances of humane treatment for him. Soviet authorities refuse to respond.

The recent release to the West of Irina Grivnina, one of the earliest and most determined Soviet activists on the subject of political abuse of psychiatry, is a welcome sign, to be sure. But efforts to aid Koryagin must continue.

Meanwhile, scores of other Soviet citizens have suffered terrible consequences for mistakenly believing their government would adhere to the human rights guarantees of the Helsinki Final Act of 1975, which the Soviet government and 34 others signed. A recent compilation by the U.S. Helsinki Watch Committee lists 50 men and women now in prison or internal exile for having participated in efforts to report Soviet human rights abuses to the West. These prisoners of conscience are drawn from across the spectrum of the Soviet population. Their numbers and diversity attest to the scale and intensity of civil repression under Gorbachev's rule:

There are Russians, Ukrainians, Jews, Georgians, Tartars and Lithuanians in exile and in work camps. Russian Orthodox and Roman Catholic priests have been imprisoned; Pentecostal Christians, Evangelical Baptists, Seventh Day Adventists and Uniate and Eastern Rite Catholic activists and clergy are behind bars. Others have been jailed on trumped-up charges for teaching Hebrew.

Among those who have been punished are handicapped people who sought better care and public accommodations and numerous Soviet citizens who have married Americans and are barred from joining their spouses abroad. In addition, tens of thousands of Jews and Armenians are seeking to emigrate to join relatives living in other countries. While there are signs of interest by the Kremlin in resuming significant emigration, Jewish groups in this country have compiled lists of hundreds of families that have waited more than a decade to leave.

Although Gorbachev in his Paris press conference last month stressed the civil right of a Soviet citizen to have a job, he neglected to mention the powerful corollary -- that able-bodied citizens can be prosecuted for "parasitism" if they do not work.

Many refusedniks have been fired from their jobs for what the Soviet media habitually describe as the "treasonous" act of seeking to live elsewhere than the U.S.S.R. They have been unwillingly thrust into a Kafkaesque legal twilight zone, fearful they will be prosecuted by the state for not holding jobs from which the state has fired them.

It is an immense irony that many of these cases of persecution are a direct result of the 1970s era of d,etente, when Moscow signed the Helsinki Act and allowed large-scale emigration in pursuit of important global political goals. While d,etente has long since faded, one of its most powerful legacies remains the sad spectacle of Soviet citizens' being punished because they believed the state's guarantees of fundamental freedoms. No substantial or lasting improvement in East-West relations can be expected if the fate of people like these is not accepted by Gorbachev, as by Reagan, as priority summit business.