John w. Hinckley Jr., after days of listening to psychiatrists describe him as an insane man driven by distorted and violent fantasies, declined to come to court yesterday.

Instead, he watched his trial on closed-circuit television in a small holding cell behind the sixth floor courtroom where he has been on trial for four weeks for the attempted assassination of President Reagan.

"He did not want to go to court this morning," one official said. Judge Barrington D. Parker told the jury that Hinckley had "elected to voluntarily excuse himself" from the day's proceedings, and he warned them not to draw any inferences from the fact that he was not present.

As the trial continued, Dr. Thomas C. Goldman, a defense psychiatrist, acknowledged that Hinckley had lied to him when he said he had not purposely bought exploding Devastator bullets for his attack on Reagan and three others outside the Washington Hilton Hotel more than a year ago.

Under cross-examination by chief prosecutor Roger M. Adelman, Goldman testified that the false statements made him "a bit less certain" about other things Hinckley told him. Nevertheless, he said, he was "still reasonably certain" that Hinckley's description of his mental state on the day of the shooting "was accurate."

Goldman, who conducted 48 hours of interviews with Hinckley after the shooting, told the jury that doubts about details of the attack would not cause him to change his diagnosis. He has testified that Hinckley suffered from a severe mental illness when he fired on Reagan and should not be held criminally responsible for his acts.

During the trial, Hinckley left court once unexpectedly and twice was excused by Parker. Parker has said that Hinckley, who appeared on several occasions to have become upset by testimony about his obsession with actress Jodie Foster, could stay out of the courtroom, but could not come and go on whim.

The psychiatrist said he interpreted Hinckley's compulsive desire for a union with Foster as the pursuit of an "idealized mother figure," adding that Hinckley perceived Reagan, like other "authority figures," as standing in the way of that union.

"Are you maintaining that he shot Mr. Reagan because Mr. Reagan was denying him access to the idealized mother figure Jodie Foster?" Adelman asked.

"He felt in some ways that was so at the moment, at the time that he decided he had to do it, yes," the psychiatrist testified.

Hinckley "had some feelings that getting rid of President Reagan would help him to get to Jodie Foster and in that sense . . . President Reagan was an obstacle. Someone who had to be eliminated," he said.

Goldman said Hinckley's pursuit of Foster was motivated mainly by "the intensely dependent infantile wish to be loved and nourished, together with the rage and sense of total dissolution of the self in the face of intolerable frustration."

The mother figure "was endowed with virtually magical powers to heal, make whole and endow life and he knew he must acquire access to her and recognition by her if life was to be supportable at all," the psychiatrist testified.

Since the infantile mind cannot accept a mother who is both "giving and frustrating," Goldman said, the idea becomes split into a idealized mother and "all prohibitive figures" who deny access to her.

Goldman said that while Hinckley's main objective was to impress Foster, he also wanted to involve her in his life, involve her in his guilt and punish her for being inaccessible to him.

Goldman acknowledged that he said in an earlier report to the court that Hinckley had "planned and premeditated a great deal" on the day of the shooting and months before, including going to a Colorado shooting range for target practice.

Hinckley told a government psychiatrist that he stood outside the Hilton before the shooting and debated with himself about whether or not to go ahead. Adelman, referring to that statement, suggested yesterday that Hinckley had in fact deliberated about attacking Reagan. Goldman said he had questioned Hinckley about the remark, but insisted that Hinckley, because of his mental illness, had no "viable choices."

However, Goldman also said under questioning by Adelman that he would agree with an earlier defense expert who testified that if Hinckley had been asked at the moment of the shooting whether it was right or wrong, he would have said it was wrong.

If such a question had been asked, Goldman testified, "I think he would have come back in some extended contact with reality. It might have at least for the moment caused him not to commit the shooting."

Hinckley had stalked both President Carter and President-elect Reagan in the months before the shooting, but Goldman told the jury that Hinckley's inner pressure had "not built up yet." When Hinckley came to Washington in December 1980 and hung around Blair House, where Reagan was staying, he was a man "flirting with disaster," Goldman said.

Hinckley flirted with getting caught when he took a photograph of himself outside Ford's Theater, where President Abraham Lincoln was assassinated, which is a short distance from FBI headquarters, Goldman told the jury.

Tuesday, Goldman testified that Hinckley also thought he might be caught by the FBI in late 1980 after he sent the agency an unsigned kidnap note about Foster, who knew Hinckley's name from notes he left for her at Yale University and from telephone calls. When nothing happened, Goldman said, Hinckley concluded "they had not put two and two together and they were stupid."

Over the objections of defense lawyers, prosecutor Adelman repeatedly questioned Goldman about Hinckley's suicidal impulses, which Goldman had testified were part of the drive that caused Hinckley to shoot Reagan. Adelman noted, and Goldman agreed, that, while Hinckley had written and spoken about suicide and said he had played Russian roulette, he had taken no action to harm himself.

On those occasions, Goldman testified, Hinckley's impulses "were not so strong that he could not control them."

Goldman discussed a short story Hinckley wrote, called "Son of a Gun Collector," in which a son brutally kills his father with a rifle. He said that the classic Oedipal complex, first described by Sigmund Freud, has some significance to his interpretation of Hinckley's thoughts.

In the Oedipal theme, drawn from Greek mythology, the father is seen as an obstacle to the son's union with his mother, Goldman explained to the jury. While Hinckley's violent story may have raised some of those notions, he strongly denied that he felt at all violent towards his father, Goldman said.

Hinckley perceived himself as an ineffectual adult and saw guns as "a way of winning the love of a woman he wants to impress," Goldman testified.