We’ve all had the experience of not being able to recall a familiar or known word and having that ‘tip of the tongue’ (TOT) sensation, which is also known as Lethologica.

People feeling TOT sensation can often recall some of the word’s features like its first letter or words that sound similar, and while TOT is normally just a short-term frustration, and happens across all age groups, its frequency does increase as we age.

But what is actually happening in our brains that makes us unable to retrieve a word from our memory that we clearly know?

While the cause of TOT is unknown, there are several theories on what’s behind it.

Clinical Neuropsychologist, Dr Marjorie Collins, explains to Mike what science believes may be happening when we experience TOT, and can also reveal what factors might increase the severity or frequency of TOT.