Forgetting Words Mid-Sentence: Causes and Explanations

Introduction

Why do we forget words mid-sentence? The science behind “tip-of-the-tongue” moments is a fascinating look at how our brains retrieve words from memory. The feeling of knowing a word but being unable to say it is a common phenomenon known as lethologica or, more commonly, a Tip-of-the-Tongue (TOT) moment. It’s a temporary memory lapse where the meaning and some of the features of a word are accessible, but the full word itself isn’t. ^[1]

What a TOT Moment Reveals About Memory

The feeling of a word being “right there” is a key part of the TOT experience and highlights how our brains store and access information. Word retrieval isn’t a single, monolithic process; it occurs in stages.

• The Semantic Stage: This is where you access the meaning of a word. When a TOT occurs, you can often describe the word’s definition, context, or category. You know what you want to say, but not how to say it.
• The Phonological Stage: This is where you access the word’s sounds. In a TOT state, this stage is blocked. You might be able to recall the first letter, the number of syllables, or similar-sounding words, but the complete set of sounds that make up the word is unavailable.

This two-stage process explains why we can feel so close to a word without being able to say it. The connection between the meaning (semantics) and the sounds (phonology) has temporarily failed.

Leading Scientific Theories for Why TOTs Occur

Neuroscientists have proposed several models to explain the precise mechanisms behind TOT moments, which can be broadly grouped into two categories.

• The Transmission-Deficit Model: This is the most widely accepted theory. It suggests that a TOT happens when the neural connection between a word’s meaning and its sound is too weak to allow for full retrieval. You have a strong grasp of the semantic information, but the signal transmission to the phonological part of the brain is incomplete, like a broken telephone wire. This model explains why aging leads to more TOTs, as these neural pathways can naturally weaken over time. ^[4]
• The Blocking Hypothesis: This theory posits that a TOT occurs when a related, but incorrect, word actively blocks the retrieval of the correct one. This is why you might get stuck on a similar-sounding word or a synonym, and no matter how hard you try, that incorrect word keeps popping up and preventing access to the one you actually want.
• The Incomplete Activation Hypothesis: This view suggests that the memory of the word isn’t strong enough to be fully activated. The memory trace is partially there, and you can sense its presence, but it hasn’t reached the threshold for conscious retrieval.

The Brain on a TOT: A Moment of Conflict

Brain imaging studies provide fascinating insights into what happens in the brain during a TOT state.

• The left temporal lobe and the hippocampus (brain regions critical for language and memory) show increased activity. These areas are working hard to search for the word.
• Simultaneously, the frontal and parietal lobes, responsible for cognitive control and self-monitoring, also light up. The anterior cingulate cortex, in particular, becomes active, likely signaling the conflict between the feeling of “I know this” and the inability to retrieve it. It’s the brain’s way of detecting a retrieval failure and prompting a more intense search.

These brain areas work in concert, creating the frustrating feeling of being “stuck.”

Factors That Increase the Likelihood of a TOT

TOT moments are not random; they are influenced by several predictable factors.

• Age: The frequency of TOTs increases with age, starting around the age of 40. This is a normal part of the aging process and not a sign of a serious memory disorder. ^[4]
• Word Frequency and Age of Acquisition: Words you use less often or that you learned later in life are more prone to TOTs. The more you use a word, the stronger its neural connections become, making it easier to retrieve.
• Bilingualism: People who speak multiple languages often experience more TOTs than monolinguals. This is because their brains have to manage multiple linguistic systems, which can lead to competition and temporary blocking between languages.
• Stress and Fatigue: Mental exhaustion and stress can impair cognitive function and word retrieval. A tired brain has a harder time accessing and activating the precise neural pathways needed for language. ^[10]

Practical Strategies to Overcome a TOT

When you find yourself in a TOT moment, there are a few simple strategies you can use to get unstuck.

• Take a Break: The most effective strategy is often to simply stop trying. A break from the active search allows your brain to reset and can lead to the word popping back into your head spontaneously a few minutes or hours later. ^[11]
• Use Cues: Try to recall the context or related information. If you’re stuck on a person’s name, think about where you met them. If it’s a word, think about its meaning or a related word. This can help re-engage the semantic networks. ^[11]
• Stay Cognitively and Physically Active: Engaging in mentally stimulating activities and regular physical exercise can help maintain cognitive health and improve memory retrieval. Some studies even suggest that higher aerobic fitness in older adults is linked to fewer TOT moments. ^[12]

When to Be Concerned

While frustrating, occasional TOT moments are a normal and healthy part of how our memory works. It’s only a cause for concern if they become so frequent or severe that they significantly disrupt your daily communication. If you find yourself consistently unable to recall common words and it’s accompanied by other symptoms like confusion or changes in behavior, it’s wise to consult a doctor to rule out an underlying neurological condition such as aphasia. ^[13]