[9] After graduating, he spent a short time treating holocaust survivors and refugees in mainland Europe,[10] and then moved to the United States where he took up a position as an instructor at the Yale School of Medicine investigating the use of lobotomies as a method of controlling depression.

[3] At Melzack's urging they wrote a paper on the Gate control theory of pain and published it in Brain in 1962; according to Wall it was read by around three people.

After expanding and rewriting the article they republished it as Pain Mechanisms: a new theory in Science in 1965 where it drew wider attention, with mostly negative comments.

[11] The paper was looked at in a new light after Wall collaborated with Bill Sweet to produce the Transcutaneous Electrical Nerve Stimulator, developed along the lines of the theory.

[10] In 1967 he returned to Britain due to threats from the CIA that refusal to disclose the political affiliations of his research group could jeopardise his funding,[12] and took up a position as Professor of Anatomy at University College London,[13] under JZ Young.

[8] In 1999 he was awarded the Royal Medal 'in recognition of his fundamental contributions to our knowledge of the somatosensory system and, in particular, pain mechanisms'.