My mind keeps on going blank. How worried should I be

Let's start with the brain

To understand what causes our mind to go blank, we need to start with how our brain usually pays attention and learns new memories.

A key brain network involved in these processes is the executive attention network. This is a network of interconnected brain regions that's important for being alert, paying attention and feeling motivated.

These brain areas are connected to regions in the outer layer of the brain, the frontal and parietal cortex, which support our planning, decision-making and sensory integration.

This executive attention network is used both for passing information to our memory systems for storage, and then later retrieving those memories when we need them.

One of the key brain chemicals that supports this network is noradrenaline, also known as norepinephrine. This controls our alertness and readiness for action.

So what happens when our mind goes blank?

Disruption in any part of the executive attention network can impact the brain's ability to pay attention and retrieve memories, leading to a blank mind.

When we're sleep-deprived

Fatigue caused by sleep deprivation or sleep disorders can impact the alerting part of the network.

When we are very tired, we can experience "local sleep ". This is where the activity in parts of our brains is sleep-like even if we are awake. This can cause the attention system to temporarily shut off, which researchers think may lead to mind blanks.

Neuroimaging research shows parts of the executive attention network are "deactivated" during mind blanking.

This likely explains what causes the "zoning out" kind of mind blank.

When we're stressed

High levels of stress or anxiety, such as what we might experience in an exam room, can result in high levels of noradrenaline. This puts the body in "fight or flight mode".

This focuses our attention on immediate threats, reducing its ability to retrieve what it sees as non-essential memories, such as information you've been revising the day before.

When we're multi-tasking

If the executive attention network doesn't encode a memory efficiently in the first place - because for example, we were multi-tasking or distracted - then it might not be easily retrieved later on. This can also lead to a mind blank.