Robert A. Baker, 84, a University of Kentucky psychology professor emeritus and a leading "ghost buster" who worked on the premise that "there are no haunted places, only haunted people," died Aug. 8 at his home in Lexington. He had congestive heart failure.

Dr. Baker was foremost a skeptic, believing that one could not assume from the start that unusual phenomena -- ghosts, UFO abductions, lake monsters, remembrances of past lives -- were real. In books and scholarly articles, he argued that they could be explained as mental states, that abductions by aliens, for example, were hallucinations -- or "waking dreams" -- that occur in the twilight zone between fully awake and fully asleep.

Much of his work involved being a sympathetic counselor to those who believed they were being toyed with or tortured by unexplainable forces.

In the 1960s, he visited a traumatized young Kentucky wife who was convinced that she was seeing a "golden-haired 3-year-old girl" in her home.

"After talking with her and her husband," he wrote, "I quickly learned that she was the only one who ever saw or heard the child. Moreover, I learned that she and her spouse wanted children desperately but had no luck. I urged them both to consider adoption, and as soon as they took these steps, the 3-year-old spirit disappeared forever."

Dr. Baker worked more than 60 cases, volunteering his time to visit those who called the university's psychology department or found him through his writings and reputation.

He often worked with Joe Nickell, a senior research fellow at the Committee for the Scientific Investigation of Claims of the Paranormal, a group based in Amherst, N.Y., whose members have included Carl Sagan, Isaac Asimov and B.F. Skinner. Nickell said Dr. Baker was seldom confrontational in his methods and knew when a little theater was needed.

One investigation took Dr. Baker and Nickell to an Indiana farmhouse, where a family was disturbed by loud noises near their children when they were sleeping. When Dr. Baker began questioning one boy, he confessed that he was responsible but begged the professor not to tell.

Agreeing to amnesty, Dr. Baker decided to solve the matter by playing to the mother's deeply religious convictions.

"He took out a little vial and told the woman with a straight face that it contained the powered bones of saints," Nickell said. "He went around upstairs sprinkling this powder, this charm, around and telling the woman this would be very effective at keeping out bad forces. . . . He did not want to offend her, and this was an emergency situation."

Robert Allen Baker Jr. was born June 27, 1921, in Blackford, Ky. His father fixed shoes, and his mother was a drugstore clerk. Both were poor and unschooled, he wrote, but "they encouraged me to read, think and get an education."

"They also, inadvertently, started me on the skeptical path by taking me at an early age to the local First Baptist Church, where the new minister -- one Percy Walker -- a kind, gentle, soft-spoken man, turned into a fiery-faced, screaming maniac every time he took the pulpit. . . . When I asked my father what was wrong with the reverend, he smiled and said, 'Religion makes some people crazy.' "

As a young man, he also grew disillusioned with ghosts after two acquaintances tracked down mysterious moans in a cave, reputedly haunted. A cracked boulder had been transforming gusts of wind into an eerie noise.

During World War II, he was an Army Air Forces cryptographer, and he began reading hungrily about human psychology during those years. "I resolved that the only thing that could save man from himself was a fully developed science of human behavior," he wrote.

He graduated from the University of Kentucky in 1948 and the next year received a master's degree in psychology there. He received a doctorate in psychology from Stanford University in 1951.

He then became a staff scientist at the Massachusetts Institute of Technology's Lincoln Laboratory, which conducted military research. In 1953, he joined the Human Resources Research Office at Fort Knox, where his work included finding ways to improve soldiers' alertness during guard duty.

At Fort Knox, he also worked as an assistant at mental hospitals and began hunting ghosts.

In 1969, after budget cuts there, he left for the University of Kentucky. He spent the first four years as psychology department chairman. He retired in 1988.

He teamed with Nickell, a former Pinkerton detective, when the latter was working on a doctorate in English at the university. They collaborated on a book, "Missing Pieces: How to Investigate Ghosts, UFOs, Psychics & Other Mysteries" (1992), which Dr. Baker called a "do-it-yourself guidebook for would-be skeptical investigators."

Dr. Baker's other books included "They Call It Hypnosis"(1990) and "Hidden Memories: Voices and Visions From Within" (1992). He found hypnosis galling, "nothing more than relaxation, suggestion and the turning on of one's imagination." He also denounced the tendency toward over-medication through "pill-popping" in "Mind Games" (1996).

He edited the volume "Child Sexual Abuse and False Memory Syndrome" (1998) and, early on, a collection of science humor called "A Stress Analysis of a Strapless Evening Gown and Other Essays for a Scientific Age" (1963).

He died on the 52nd anniversary of his marriage to Rose Paalz "Dolly" Baker, who survives, along with six children and seven grandchildren.

Dr. Robert Baker's suspicions about "ghosts" formed at an early age.