The tip-of-the-tongue (TOT) phenomenon is a cognitive experience characterized by a temporary inability to retrieve specific information from memory despite having a strong feeling of knowing the information. Although individuals cannot access the target word or detail, they frequently recall related elements, such as its initial letter, syllable count, or context. This partial retrieval often causes frustration, as one might recognize a familiar face or know that a name starts with a specific letter but cannot fully recall it.

The prevailing theory regarding TOT suggests that the phenomenon arises from retrieval failure, which occurs when there is a disruption in the connection between stored memory and the retrieval process. This disruption is likely due to interference from similar words or concepts stored in memory, causing confusion and misdirection during recall. Another contributing factor may be the weakness of the memory trace itself. For example, a person may struggle to recall an actor's name, remembering only that it begins with "B," while related names or sounds prevent access to the correct answer.

Interference plays a crucial role in TOT episodes. The brain often retrieves incorrect but similar words because language is stored and organized in verbal memory. Words with similar phonological structures or meanings are closely linked, leading to retrieval errors. For instance, while solving a crossword puzzle, a person might initially think of the word "bandage" instead of "bandanna" in response to the clue "colorful scarf." This mistake occurs because the brain prioritizes words that share similar sounds or patterns, even if they are semantically incorrect.