Why does my mind go blank?

It one of the main reasons people are scared of public speaking...

what if my mind goes blank?!

And we all know that feeling, right? You have rehearsed that speech, standing in front of your bedroom mirror you have it down pat.  But for some reason, when you are up on stage and standing in front of all those people (with all those eyes staring at you) your mind suddelnly stops working.

For a long time, I just assumed that it had to do with nerves or not practising enough. Untill I started researching the science and relaised there's a lot more to it.

But before we look at the science, we have to look at how different parts of the brain work...

1. The first is the hypothalamus - a small part of the brain. In fact, it's about the size of an almond. But it's important.

Put simply, it is the bridge between your emotions and your physical sensations.

It plays an important role in the nervous system as well as in the endocrine system. Why is this important? Because it is responsible for the amount and type of hormones that flow through your body.

2. Second is the hippocampus.  Named after its resemblance to the seahorse (ish).

Humans have two of these, and it is an important part of the brain.  It is crucial for the retrieval of facts and concepts.  In fact, in Althzeimers disease, it is one of the first areas to suffer damage.

Psychologists and neuroscientists generally agree that the hippocampus plays an important role in the formation of new memories about experienced events.

3. The third is the prefrontal cortex (PFC). Located behind your eyes, this is the calm, cool, rational part of your brain. All the things that suggest you, as a human being, are in control are largely mediated here: things like working memory (the ability to hold and manipulate information in your mind), impulse control (the ability to dampen unwanted behavioural responses), decision making (the ability to select a proper response between competing possibilities), etc.

How it works when you're rehearsing

When you're rehearsing your speech in your bedroom it's easy right? Becuase it's a no-risk situation.  If you stumble over a line or forget something - it doesnt mattter.  You can just start again. 

In other words, you are able to engage in cold cognition. This is the term given to logical and rational thinking processes.

When you are rehearsing in a quiet bedroom with no one watching, the hypothalamus slows down the production and release of key stress hormones while the PFC and hippocampus are confidently chugging along unimpeded.

How it works on stage

Now, let's move to the stage.  Perhaps it's a presentation in fron of colleagues at work. 

We have now moved from the world of no-risk to high-risk.  It may even trigger a set of negative thinking.

My boss is sitting just over there.  If I stuff this up in front of everyone, I can kiss that promotion goodbye

Hello hot cognition!

This is the term given to non-logical and emotionally driven thinking processes. Hot cognition is typically triggered in response to a clear threat or otherwise highly stressful situation.

With this type of loaded thinking, giving the speech is no interpreted by your body as the threat. When a threat is detected, the hypothalamus stimulates the generation of several key stress hormones, including norepinephrine and cortisol.

Large levels of norepinephrine enter the PFC and serve to dampen neuronal firing and impair effective communication.

What does this mean?  The PFC stops working and essentially wipes out your working memory!

It also stops the rational, logical PFC from influencing other brain regions.

But wait theres more.

At the same time, large levels of cortisol enter the hippocampus and not only disrupt activation patterns there, but also (with prolonged exposure) kill hippocampal neurons. This serves to impede the ability to access old memories and skews the perception and storage of new memories.


In short, when you interpret the speech as a threat- a stress response is triggered in your body.  Your working memory is wiped clean, your recall mechanisms are disrupted, and your hypothalamus overrides the normally rational cold cognition driven by the PFC.

So can we do anything about it?

Of course!  First of all let's start with some of the triggers.

1. Get used to the silence

When you're not used to speaking in public, one of the most uncomfortable moments come with the silence.  So, you compensate by filling in any possible gap with words. 

Not only does this make it hard to listen to you - it puts even more pressure on you if you do have a mind blank.

The answer is to get used to the silence.  When you rehearse, also include long pauses at the end of each paragraph.  If you're really keen, record your rehearsals and watch it back. Before you watch the recording, estimate how long you thought the silence went for and then time it.  You will be surprised at how short these little gaps were.

2. Don't try to be perfect

The possibility of a mind blank increases when you are aiming for perfection.  Before you get onto stage, accept the fact that your speech will not be perfect.  No one's speech is ever perfect. 

As Dale Carnegie said, “There are three speeches...The one you practiced, the one you gave, and the one you wish you gave.”