Semantic satiation occurs when you say or think of a word for so long that it loses its meaning.
It has been used by speech therapists to reduce speech anxiety with stutterers by creating semantic satiation through repetition, thus reducing the negative emotions linked to the pronunciation of certain words.
“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.”
– Leon Jakobovits James