Skip to content

Why Does Your Mind Go Blank During an Exam?

  • Sean 

Sometimes we sit down for an exam and find our minds just go blank during an exam. It was only years later that I realized exactly how to fix it.

During an exam, it’s common to draw a blank and struggle to recall even the basic information that we studied.

This can be caused by a variety of factors including practicing studying techniques that don’t emphasize encoding and active recall. By addressing these issues you can significantly reduce the likelihood of drawing a blank on your next exam.

This article explains some studying technique-related causes of blanking on an exam as well as a couple of non-studying related issues that can lead to the same issues.

Let’s get into exactly why you blanked out on your last exam.

4 Reasons You Blanked Out During Your Last Exam

1. Not encoding the exam content

Certain studying techniques such as flashcards are very retrieval-based and this can become a limitation if you don’t combine them with other techniques that emphasize deep encoding.

The forgetting curve shows this very well. In general, when you learn information, its retention drops off rapidly. This is even more pronounced if you don’t focus on encoding the material when you learn it.

Here is an image I created to visually display the difference in retention over time when you fail to use techniques that emphasize encoding.

The forgetting curve with both shallow vs deep encoding

Of course, this is only after a single studying session. You can effectively “reset” the very rapid decline of the forgetting curve by repeatedly retrieving the information.

However, the drop-off in retention remains significant. If you try to cram lots of information at once, it’s possible that so much information will have been forgotten by exam time that your performance will suffer greatly.

This is why it’s important to use techniques that promote high-quality encoding from the start. This way, when you write the exam you won’t have forgotten nearly as much information.

But how do we practice high-quality encoding?

This is a huge topic but there are some basics that, if you master, you will encode the material much more effectively.

Here’s a brief list of a few techniques that promote deep encoding:

  • Mindmaps: Mindmaps are very effective for getting a logical big-picture view of the topic and using high-quality imagery to increase retention. This is my favorite way to encode information.
  • Teaching others or an imaginary student: You can also teach other people
  • Whenever you learn something ask how it’s related to everything else: This is something you should do when creating a mindmap, explain while teaching, or just in general. This is actually the thing that makes these other techniques the most effective for encoding.

2. You tricked yourself into thinking you were ready

Another possibility is that you tricked yourself into thinking you were ready, but actually you weren’t. This is something that happens if you are not testing yourself in your revision or using the wrong revision techniques period.

If you use a lot of recognition-based studying techniques learning illusions can happen very easily. Recognition-based studying is when you use recognition instead of active recall. Examples of this include, rereading information and summarizing while reading.

The research is clear on this. Using recognition instead of active recall is worse for retention.1

What happens is that when students look over the information and recognize it, they equate recognizing it to knowing it. Even experienced students who know about this still can make this mistake. It’s very easy to do.

So how do we avoid tricking ourselves?

You need to practice active recall instead of recognition. This means recalling the information purely from memory. Not only will avoid the illusion that you are ready but it’s also just a best practice to use when studying because active recall is much more effective than recognition.

If you want to level up your studying with active recall, I have an entire article that explains 9 proven active recall techniques to ace your upcoming exam. If you properly follow these techniques, it’s very likely that your exam performance will increase.

3. Lack of sleep

Lack of sleep can have a significant impact on cognitive processes like working memory, which can make recalling information on exams difficult.

In addition, sleep is important for the consolidation of memories. This is the process in our brains that stabilizes and strengthens our memories during sleep.2 So if you skip out on your sleep to study it’s highly likely that you will forget a great deal of what you needed to remember by exam time.

In addition, it has been demonstrated that getting enough sleep is crucial for an upcoming exam. Students who sleep less have been found to just get lower grades in general compared to ones that prioritize getting enough sleep.3

In general, try to get a minimum amount of about 6 hours of sleep before an exam. But there is a lot more to this topic, especially the importance of your sleep history.

I wrote a whole article on the minimum sleep you need before an exam if you are interested in this topic.

Lastly, a lack of sleep can also tie into the last reason you might have blanked on your exam, stress.

4. Exam Stress

Exam stress is common among university students. In a 2015 survey, it was found that more than 50% of students showed at least one physical symptom of stress.4

In the same survey, it was also found that students who had higher levels of stress also got worse grades than students with lower exam stress.

This is likely because stress has been found to mitigate cognitive processes that are important to exam performance. These include a reduction in both working memory and cognitive flexibility.5

If you struggle with exam stress there are a few things you can try to mitigate it.

Talk to a college or university counselor: these institutions have allocated these professionals for issues like this. If you need help with exam stress, you should seek it out.

Another general thing is to just strive for better life habits. Here is a list of some basic things you can improve that should help with exam stress in the long term.

The Takeaway

If you don’t study using techniques that emphasize both encoding and active recall you are at risk of drawing a blank on your next exam. Beyond this, there are also non-studying related reasons like lack of sleep and exam stress that can lead to these issues.


  1. Karpicke, J. D., & Grimaldi, P. J. (2012). Retrieval-Based Learning: A Perspective for Enhancing Meaningful Learning. Educational Psychology Review, 24(3), 401–418.
  2. Walker, M. P., & Stickgold, R. (2004). Sleep-Dependent Learning and Memory Consolidation. Neuron, 44(1), 121–133.
  3. Fakhari, A., Kheradmand, N., & Dolatkhah, N. (2016). Sleep Duration the Night before an Exam and Its Relationship to Students’ Exam Scores. British Journal of Medicine and Medical Research, 15, 1–6.
  4. Shields, G. S., Sazma, M. A., & Yonelinas, A. P. (2016). The effects of acute stress on core executive functions: A meta-analysis and comparison with cortisol. Neuroscience & Biobehavioral Reviews, 68, 651–668.