Why do People Blank Out?

Blanking out is a term used to explain common mental absences which can occur in various scenarios. Whether it is during a conversation, while listening to a lecture or in the middle of a task, individuals find themselves zoning out or staring into space, becoming unaware of their surroundings and unable to recall what they were doing. So, why do people blank out?

1. Cognitive overload

Cognitive overload is when the human brain is overwhelmed by too much information, this causes lapses in attention or memory, or in other words, “zoning out”.

According to a study that is published in the journal “cognitive psychology”, when individuals are required to process excessive information, their performance declines, which can result in lapses in attention(Sweller, 1988). This phenomenon is particularly prone to happen in high pressure environments such as exams or public speaking, where the individual can feel large amounts of stress.

2. Stress and anxiety

Blanking out can also be used as a coping mechanism when an individual feels a large amount of stress. When individuals are stressed, our bodies are hard-wired to shift into a fight or flight response, this causes those individuals to enter a state of temporary relapse. This is supported by research from the American Psychological Association, which indicates that high levels of stress can impair working memory and decrease attention span (APA, 2019).

In stressful situations, the brain prioritizes survival over cognitive function, this leads to moments where a person forgets what they were doing or saying. This is often referred to as "brain freeze," (not the cold one!) a temporary inability to think clearly.

3. Fatigue or sleep deprivation

Physical or mental fatigue plays a huge role in the likelihood that people are going to blank out. Lack of sleep affects cognitive processes, such as attention or memory. The study conducted in Sleep Medicine Reviews notes that sleep deprivation can lead to blanking out(Goel et al., 2009).

When we are tired, the brain struggles to maintain focus, making it easier to lose track of conversations or thoughts. This is why many people find themselves zoning out during long lectures or meetings when they haven’t had enough rest.

Conclusion

In conclusion, blanking out is a phenomenon that is influenced by cognitive overload, stress and anxiety, or sleep deprivation. Understanding these factors can help individuals manage their mental state better, leading to improved focus. By recognising the potential conditions that lead to blanking out, individuals can take action to help mitigate its effects, such as sleeping more or managing stress.

References

1. Stress (2018). Stress effects on the body. [online] https://www.apa.org. Available at: https://www.apa.org/topics/stress/body [Accessed 6 Oct. 2025].

2. Goel, N., Rao, H., Durmer, J. and Dinges, D. (2009). Neurocognitive Consequences of Sleep Deprivation. Seminars in Neurology, [online] 29(04), pp.320–339. doi:https://doi.org/10.1055/s-0029-1237117.

3. Killingsworth, M.A. and Gilbert, D.T. (2010). A Wandering Mind Is an Unhappy Mind. Science, [online] 330(6006), pp.932–932. doi:https://doi.org/10.1126/science.1192439.

4. ‌Andyʼs working notes. (2024). Sweller, J. (1988). Cognitive load during problem solving: Effects on learning. Cognitive Science, 12(2), 257–285. [online] Available at: https://notes.andymatuschak.org/z9oJyCh2UgEHU1LrkqNGDxm [Accessed 6 Oct. 2025].

5. Sweller, J. (1988). Cognitive Load During Problem Solving: Effects on Learning. Cognitive Science, [online] 12(2), pp.257–285. doi:https://doi.org/10.1207/s15516709cog1202_4.