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How the neuroscience of uncertainty can help you make better decisions

A complex series of chemical processes are triggered in our brains when we are confronted with uncertainty.

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Published: January 26, 2023 at 2:40 pm

When you hear the word ‘uncertainty’ what do you feel? Scared, anxious, excited or challenged? As humans we have a dichotomy of needs; part of us needs to feel safe, secure and to have some routine, and yet another part of us needs variety and opportunity.

Life presents us with uncertainty and with change, and over the last three years this has been true to an even greater degree than usual. With many global challenges still ongoing, we are likely to face even more of the unknown - so we had better get used to managing it.

We need to hack into how our brain actually responds and detects uncertainty. By understanding this, we can learn to let go of what we can't control – and improve our decision making. So, how do we detect uncertainty and which part of the brain is responsible for it?

Researchers have found that noradrenaline is the key chemical involved in our response to uncertainty. Noradrenaline is a neuromodulator; it works within the brain to affect inhibitory or excitatory signals that brain cells receive.

To investigate the role noradrenaline plays when we are faced with uncertain events, scientists at MIT conducted an intriguing experiment with mice. The animals were conditioned to push a lever down when they heard a high frequency by rewarding them with a drink of water. They also learned they'd receive an unpleasant puff of air if the lever was activated when a low frequency noise was played. Simple enough. But the researchers also added in an element of uncertainty, sequencing a sound where the frequency was unclear.

From this experiment, the researchers discovered that a small area of the brainstem called the locus coeruleus – an area that modulates noradrenaline – was essential in detecting uncertainty. When the high frequency was clear and the reward was expected for the mice, their noradrenaline release was small. But when the frequency wasn’t clear, and the reward was a surprise, the release was much larger. However, overall the mice were less likely to take action and push the lever down when reward was uncertain.

The study's conclusion: the mice brains learned to deal with different levels of uncertainty – and that the locus coeruleus is perhaps key to this process.

Another study – this time with humans – carried out at University College London, added two other neuromodulators, acetylcholine and dopamine, to the list of chemicals known to regulate our reaction to uncertainty. After running an experiment that asked participants to predict changing sequences of symbols, they discovered that acetylcholine helps us adapt to how our environment is changing and dopamine triggers us to action.

With any decision in the midst of uncertainty there is a balance of risk and loss, and whilst these chemicals underly the process of how we detect, adapt and act, there is also a process going on in one particular area of the brain, the inner prefrontal cortex, that has a huge impact on our ability to make decisions.

It is this area that scientists from Tel Aviv University found dictates our avoidance behaviour when under stress. They found that subjects’ neurons here were proven to respond much more to loss (negative outcome) than to gain (reward outcome) when they had them play a computer game that involved risk and opportunity. If a subject lost, it provoked a response in their hippocampus – a brain area involved in memory process and feelings of anxiety – and they became more risk averse.

This is helpful in understanding our reluctance in life to expose ourselves to uncertainty and how sometimes we shy away from making big decisions.

The way our brains deal with uncertainty plays a key role in how we approach life. Once we understand our cognitive and emotional responses to uncertainty are a natural, human process, perhaps those big decisions can seem less intimidating – and we can make better choices.

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