Ullman completed training in neurology and psychiatry and, after returning from military service, entered private practice in 1946.
In 1961 he also founded one of the first sleep laboratories in New York City at the Maimonides Medical Center, devoted to the experimental study of dreams and telepathy.
Ullman was also Clinical Professor of Psychiatry Emeritus at Albert Einstein College of Medicine and was a president of both the Parapsychological Association and of the American Society for Psychical Research.
Hansel also wrote there had been poor controls in the experiment as the main experimenter could communicate with the subject.
[7] An attempt to replicate the experiments that used picture targets was carried out by Edward Belvedere and David Foulkes.