Semantic satiation

Semantic satiation (also semantic saturation) is a psychological phenomenon in which repetition causes a word or phrase to temporarily lose meaning for the listener, who then processes the speech as repeated meaningless sounds.

History and Research
The phrase "semantic satiation" was coined by Leon Jakobovits James in his doctoral dissertation at McGill University, Montreal, Canada awarded in 1962. Prior to that, the expression "verbal satiation" had been used along with terms that express the idea of mental fatigue. The dissertation listed many of the names others had used for the phenomenon:

"Many other names have been used for what appears to be essentially the same process: inhibition (Herbert, 1824, in Boring, 1950), refractory phase and mental fatigue (Dodge, 1917; 1926a), lapse of meaning (Bassett and Warne, 1919), work decrement (Robinson and Bills, 1926), cortical inhibition (Pavlov, 192?), adaptation (Gibson, 1937), extinction (Hilgard and Marquis, 1940), satiation (Kohler and Wallach, 1940), reactive inhibition (Hull, 19113 [sic]), stimulus satiation (Glanzer, 1953), reminiscence (Eysenck, 1956), verbal satiation (Smith and Raygor, 1956), and verbal transformation (Warren, 1961b)." (From Leon Jakobovits James, 1962)

The dissertation presents several experiments that demonstrate the operation of the semantic satiation effect in various cognitive tasks such as rating words and figures that are presented repeatedly in a short time, verbally repeating words then grouping them into concepts, adding numbers after repeating them out loud, and bilingual translations of words repeated in one of the two languages. In each case subjects would repeat a word or number for several seconds, then perform the cognitive task using that word. It was demonstrated that repeating a word prior to its use in a task made the task somewhat more difficult.

The explanation for the phenomenon was that verbal repetition repeatedly aroused a specific neural pattern in the cortex which corresponds to the meaning of the word. Rapid repetition causes both the peripheral sensorimotor activity and the central neural activation to fire repeatedly, which is known to cause reactive inhibition, hence a reduction in the intensity of the activity with each repetition. Jakobovits James (1962) calls this conclusion the beginning of "experimental neurosemantics."

Applications
An application has been to reduce speech anxiety by stutterers by creating semantic satiation through repetition, thus reducing the intensity of negative emotions triggered during speech.