By Sophie Andrews, Associate Professor and Lead, Healthy Brain Ageing Research Program, Thompson Institute
WE’VE all experienced it.
You walk into a room and suddenly forget why you’re there.
You freeze during an exam and cannot recall an answer you studied the night before.
Or someone asks you a question and your mind goes completely blank.
These moments can feel frustrating or stressful.
But researchers say occasional “mind blanking” is actually a normal part of how the brain works.
Psychologists have long known our thoughts usually flow in a stream of consciousness. Sometimes our attention is focused.
At other times our mind wanders.
But researchers estimate that roughly 15 percent of the time our thoughts may disappear entirely.
During these moments, people report having no thoughts at all, a phenomenon known as mind blanking.
This might occur during an exam when answers vanish from memory, or when you walk into a room and forget your purpose.
It can also occur when we are not consciously thinking about anything.
Someone might ask you a question and you realise you had “zoned out”.
Some people experience this more often than others.
Those with attention deficit hyperactivity disorder (ADHD) or anxiety report mind blanking more frequently.
It is also more common when people are sleep deprived, after intense physical exercise, or in certain neurological conditions such as Lewy body dementia.
Researchers believe the phenomenon is linked to a system in the brain called the executive attention network.
This network helps us stay alert, focus on tasks and retrieve memories.
It works with areas in the frontal and parietal parts of the brain that support planning, decision making and processing sensory information.
A brain chemical called noradrenaline plays a key role in keeping this system alert and ready for action.
If this attention network is disrupted, the brain may struggle to focus or retrieve memories, resulting in a brief mental blank.
Sleep deprivation is one common cause.
When people are extremely tired, parts of the brain can briefly enter a sleep-like state even while the person remains awake.
High stress can also trigger mind blanking.
Anxiety increases noradrenaline levels and activates the body’s fight or flight response, shifting attention toward immediate threats rather than recalling stored information.
Distraction or multitasking can contribute as well, because memories that were never properly stored are harder to retrieve.
Experts recommend seeing a GP if mind blanking becomes more common, starts suddenly, or interferes with daily activities.
